Page 2 of 4 FirstFirst 1234 LastLast
Results 51 to 100 of 153
  1. #51
    mtbr member
    Reputation:
    Join Date
    Sep 2015
    Posts
    658
    last year, i watch a labor foreman send his 5 man crew into the bushes wacking away with machetes and line trimmers. all five were crusty with the pink lotion for a week. they were crushed.

    tough folks. one was a cute young woman, and they never complained. just kept working.
    Santa Cruz 5010 C
    Surly Crosscheck.

  2. #52
    Moderator Moderator
    Reputation:
    Join Date
    Apr 2011
    Posts
    1,968
    I want to right up a BoB trailer with a pair of herbicide sprayers with a handle bar mounted releases so I could just ride along giving a quick shot to the left or right side of the trail as needed. Maybe MTBR could fund the project and we could share it around the region every spring.

  3. #53
    fc
    fc is online now
    mtbr founder Administrator
    Reputation: fc's Avatar
    Join Date
    Aug 1996
    Posts
    26,272
    Quote Originally Posted by Metamorphic View Post
    I want to right up a BoB trailer with a pair of herbicide sprayers with a handle bar mounted releases so I could just ride along giving a quick shot to the left or right side of the trail as needed. Maybe MTBR could fund the project and we could share it around the region every spring.
    herbicide? Good intent but this weed is the chuck norris of cockroach weeds.
    IPA will save America

  4. #54
    mtbr member
    Reputation:
    Join Date
    Apr 2015
    Posts
    206
    Jewelweed lotion stuff I have is awesome. Put it on after contact and apply like crazy at first sign of a rash. I swear it works.

  5. #55
    mtbr member
    Reputation:
    Join Date
    Apr 2015
    Posts
    206
    Quote Originally Posted by fc View Post
    herbicide? Good intent but this weed is the chuck norris of cockroach weeds.
    I used some vegetation killer last spring on a local trail. Right now all the oak I sprayed is yet to sprout. All the other stuff is in full on growth mode. Not sure it killed it, but it is still leafless.

  6. #56
    mtbr member
    Reputation:
    Join Date
    Jan 2017
    Posts
    162
    Quote Originally Posted by prozach0215 View Post
    I used some vegetation killer last spring on a local trail. Right now all the oak I sprayed is yet to sprout. All the other stuff is in full on growth mode. Not sure it killed it, but it is still leafless.
    There is a lot of good information about removing large amounts of poison oak on the net, but also some bad information (such as spraying, which can't work on large areas simply because you'd need a helicopter to drop fire-buckets worth of the stuff).

    Yet, I personally find spraying useful AFTER I cut the vines, especially since much of the poison oak I encounter is in very steep hillsides and stream beds (which makes the mechanics a special case).

    Generally I go "below" the vine, and I follow the vine to the "mother root" (if I can), usually I'm a foot above the ground on a "nest" of poison oak and crawling since you can't possibly stand up when it's that thick.

    Then I cut the vine and immediately spray a 40% mix of glyphosate (which I buy in 5-gallon jugs at the seed shop near the Home Depot and Frys on Hamilton and Highway 17). I don't dilute the stuff I buy, but all the research I've read says you can dilute it a lot.

    Since you're crawling around, you don't spray with those typical 2-gallon pump action sprayers, but instead you keep in a belt pouch a small half-Windex-sized hand sprayer for spritzing plants.

    You end up refilling it a lot, but it's easier to carry when you're crawling around literally under and over the poison oak vines.

    Many say you should add a few drops of surfactant (e.g., dish detergent) since there are better solutions than glyphosate specifically made for poison oak, but I find that the glyphosate straight works just fine.

    Some have done studies on Scotch Broom and Spanish Broom, both of which can be handled the same way with the cut-and-spray method, where some find you need to spray in the first five minutes after cutting while others say you can spray a day later. Hence, I carry the spray with me and cut-and-spray in basically the same action.

    NOTE: Scotch Broom is best handled right about this time of year, when the ground is saturated and they can easily be pulled out, taproot and all.


    BTW, I've ruined far too many pairs of clothes, but here is just my new pair of jeans, where you can see the tell-tale splotches of urushiol (black lacquer) where they show up after being oxidized in the wash as black marks.

    Luckily, AFAICT, the oxidized urushiol is not contagious (bearing in mind that the urushiol isn't what your body reacts to - your body reacts to the quinone).

  7. #57
    mtbr member
    Reputation:
    Join Date
    Jan 2017
    Posts
    162
    Quote Originally Posted by fc View Post
    Your camera is fine. It's just out of focus as the camera is focusing on the busy background. If it's a cellphone camera, touch the subject on the screen and it should focus there. Otherwise if it's a real camera, half-press the shutter button until it finds your subject.
    Yeah. It's a stinky ancient Android cellphone camera. I'm not high tech like most of you guys. I don't even use GPS unless I have to (where it's basically impossible to get lost in these mountains since you can see for 20 miles in most directions).

    Here's a better picture I snapped just for you with that camera, this time with better focus!

  8. #58
    mtbr member
    Reputation: B1KER's Avatar
    Join Date
    Jul 2006
    Posts
    1,026
    That post made me think about the alcohol and a towel thing that FC posted about. Do you think having a spray bottle that's like half alcohol half water would work to spray on ya and wipe off with a towel? Or do you think to just use straight alcohol in a little spray bottle would be better?
    </robert> ::: B1KER.com - Be One

  9. #59
    mtbr member
    Reputation:
    Join Date
    Jan 2017
    Posts
    162
    Quote Originally Posted by fc View Post
    Your test and bravery is not entirely valid since the palms of hands CANNOT get oak. Pores not big enough. Put it on your forearm!!
    You sure do know how to challenge a guy to a one-armed duel!

    It's hard to press poison oak against your bare skin on one arm and snap pictures with an ungainly cellphone camera with the other hand you know.

    Try it. You'll see.

    With my bare hands, I pinched off that shoot of fresh poison oak and laid it on my forearm, just for you!


    First I just touched it lightly against my skin, but I figured you wouldn't consider that enough of an exposure:


    So I pushed it harder against my skin, just for your satisfaction:


    Then I laid it on my forearm, weeping from one end where I pinched it off.


    Funny thing, my neck started tingling when I did this, as if my brain was already telling my body to start itching!

  10. #60
    mtbr member
    Reputation:
    Join Date
    Sep 2015
    Posts
    658
    The poison oak this year-024.jpg
    Quote Originally Posted by B1KER View Post
    That post made me think about the alcohol and a towel thing that FC posted about. Do you think having a spray bottle that's like half alcohol half water would work to spray on ya and wipe off with a towel? Or do you think to just use straight alcohol in a little spray bottle would be better?
    i do exactly that. i use it for everything..clean a grubby lens, wiping down a nasty knife before i slice an apple. here it is. i keep one of these in all my cars. and my office. i have wiped down with it after dicking with poison oak, to not take chances.
    Santa Cruz 5010 C
    Surly Crosscheck.

  11. #61
    mtbr member
    Reputation: B1KER's Avatar
    Join Date
    Jul 2006
    Posts
    1,026
    Quote Originally Posted by Boomchakabowwow View Post
    Click image for larger version. 

Name:	024.jpg 
Views:	61 
Size:	67.4 KB 
ID:	1124566

    i do exactly that. i use it for everything..clean a grubby lens, wiping down a nasty knife before i slice an apple. here it is. i keep one of these in all my cars. and my office. i have wiped down with it after dicking with poison oak, to not take chances.
    So just straight rubbing alcohol or do you dilute it at all?
    </robert> ::: B1KER.com - Be One

  12. #62
    mtbr member
    Reputation:
    Join Date
    Jan 2017
    Posts
    162
    Quote Originally Posted by B1KER View Post
    That post made me think about the alcohol and a towel thing that FC posted about. Do you think having a spray bottle that's like half alcohol half water would work to spray on ya and wipe off with a towel? Or do you think to just use straight alcohol in a little spray bottle would be better?
    That's an interesting question because you'll note that at one point I said it could almost be better if you don't wash for a week before you go out into heavy infestations of poison oak.

    You know how Ivy Block was discovered?

    Firemen didn't get poison oak under their armpits.

    The government paid a company to investigate why, and it turned out that the company we paid now sells us the product we paid for them to essentially discover and develop what is essentially underarm deodorant (of sorts).

    Basically, the bentonite (well, it's a special bentonite quaternium-18 bentoquatam 5.0%) is basically "dirt" and oil on your skin that adsorbs (and probably absorbs) the urushiol as far as I can tell (nobody really says for sure).

    My point is that it's probably a "good thing" to have dirty oily skin, which you won't have the moment you swipe that alcohol cloth on it, right?

    In fact, since I pinched off that poison oak shoot with my bare hands, guess what I did immediately after? I sprinkled my fingertips in some loose nearby soil since I was definitely exposed to some oil as I pinched off the delicate shoot.

    Had I carried any baby oil type cream, I could have prophylactically covered my fingers in that, or just a paste of mud (or just my normal sweat and grime).

    So, what I'm saying is that putting anything on your skin to protect you from the urushiol is a good thing, and washing off the urushiol is a good thing, but if you wash off the urushiol, you also wash off the oil and dirt on your skin which was protecting you.

    So, my take (which isn't the only take so take what I say with a grain of salt), is sure, it would be fine to wipe with alcohol (or even just soap and water or even very mild bleach), but don't expose that skin again to poison oak in the same trip (or, I guess, wipe it each time).

    Anyway, the way I go through poison oak would drive me nuts if I stopped and swiped every time I touched the stuff, so I just assume I've been exposed, and I washed my arm with liquid dish detergent when I got home a couple of hours later.


    But, to summarize the answer, certainly you can remove the sap (I have never been able to find the concentration of urushiol in the sap, so, you're probably exposed more to sap than to urushiol, although it takes very little urushiol to be "infectious" so, that you are more exposed to "sap" than to "urushiol" is a minor distinction in practice).

  13. #63
    mtbr member
    Reputation: B1KER's Avatar
    Join Date
    Jul 2006
    Posts
    1,026
    What I was saying was just to do something like this at the end of the ride before I jump in my truck. I'm assuming that's what the other poster was saying he does as well. Not on the trail.
    </robert> ::: B1KER.com - Be One

  14. #64
    mtbr member
    Reputation: markm62's Avatar
    Join Date
    Dec 2013
    Posts
    102
    I have some alcohol in a bottle but a spritzer and paper towels is a good idea.

    So... this year I'll be using technu and Ivy X before, alcohol immediately after, and dawn and mean green for specific spots when I shower. All good (I hope)

  15. #65
    mtbr member
    Reputation:
    Join Date
    Jan 2017
    Posts
    162
    Quote Originally Posted by B1KER View Post
    So just straight rubbing alcohol or do you dilute it at all?
    Here's the problem.
    a. Alcohol slightly damages your skin
    b. Bleach slightly damages your skin
    c. Abrasives slightly damage your skin
    d. Dish detergent is designed to be "gentle" with your skin (but it also damages it, but far less)

    You don't want to damage your skin EXCEPT if you're trying to get rid of poison oak that is a day or three old (which is, after all, what your body does with its immune response when it throws all those anti-personnel cytokine grenades).

    So, my take is that dish detergent is about as rough of a chemical as I would want on my skin if I was constantly applying it every time I suspected I just brushed up against a poison oak vine.

    Going back to your question, alcohol, I think, would be fine to remove the sap, where you won't be able to get 100% ethanol if you wanted to, although I have it (it's about 98% reagent grade).

    I don't drink hard alcohol straight, so I was surprised when I went to a local liquor shop to find out I couldn't even get everclear in a decent concentration in California. So, basically all your alcohol is gonna be diluted (yes, I know you're probably talking isopropyl alcohol but the point is the same).

    It's gonna be diluted anyway, about 70% right?

    Even so, it's probably a good idea to dilute it further, not for the sap, but to protect your skin. Personally, I'd use plain old soap (I'm not big on complications unless they make a big difference).

    And, personally, I didn't even wash until a few hours after doing THIS for fc, by pressing a cut vine (albeit an old cut vine I had cut about a year ago) against my forearm.


    Here's me holding that cut vine at the same time I snapped these pictures, but I took a shot of this exact vine seeping when I first cut it about a year ago. I've been keeping tabs on it for the entire year, to see if I can tell when a plant was bruised by the way the sap oxidizes black on the outside.

  16. #66
    mtbr member
    Reputation:
    Join Date
    Jan 2017
    Posts
    162
    Quote Originally Posted by B1KER View Post
    What I was saying was just to do something like this at the end of the ride before I jump in my truck. I'm assuming that's what the other poster was saying he does as well. Not on the trail.
    Ah. Yes. That makes a LOT more sense (from a practical standpoint).
    In fact, it's the PERFECT time to wipe up, although remember it's on your clothes too.

    I can snap a photo of my old jeans to give you an idea how the spots are in the strangest places (don't even ask me how they got there 'cuz I don't know).

    Gimme a few minutes to dig up those old (ripped) jeans and shirts that I keep for doing trail work.

  17. #67
    mtbr member
    Reputation: B1KER's Avatar
    Join Date
    Jul 2006
    Posts
    1,026
    Quote Originally Posted by woodrock View Post
    Ah. Yes. That makes a LOT more sense (from a practical standpoint).
    In fact, it's the PERFECT time to wipe up, although remember it's on your clothes too.

    I can snap a photo of my old jeans to give you an idea how the spots are in the strangest places (don't even ask me how they got there 'cuz I don't know).

    Gimme a few minutes to dig up those old (ripped) jeans and shirts that I keep for doing trail work.
    No worries, I get the idea. Thanks for all the information!
    </robert> ::: B1KER.com - Be One

  18. #68
    mtbr member
    Reputation: B1KER's Avatar
    Join Date
    Jul 2006
    Posts
    1,026
    On another note I never used Tech nu because it was so expensive. But I found that IvyX online for pretty cheap! https://www.pksafety.com/ivy-x-post-...ogsaAjkT8P8HAQ
    </robert> ::: B1KER.com - Be One

  19. #69
    Lurkers Union - Local 916
    Reputation:
    Join Date
    Nov 2009
    Posts
    362
    Great thread, but dear god in heaven those pics of it on you are making me squirm.

  20. #70
    mtbr member
    Reputation: Trackho's Avatar
    Join Date
    Sep 2011
    Posts
    353
    Im generally not that bothered by it unless I have some kind of open scrape that it gets into. But Ive noticed that with the wet trails--seems like I am getting a mild case on my legs where water/mud gets splashed up. I guess it makes sense that the spores/oils or whatever remain active in rain runoff/mud--anyone else experience this??

  21. #71
    mtbr member
    Reputation:
    Join Date
    Jan 2017
    Posts
    162
    Quote Originally Posted by BStrummin View Post
    Great thread, but dear god in heaven those pics of it on you are making me squirm.
    Speaking of squirming from exposure to urushiol, I dug up a few pairs of my jeans, where the old adage holds that if you don't know what color poison oak is, then you've never been in poison oak (since you can clearly see the black oxidized urushiol on the back of my pants in vine-shaped circles and slashes).


    The front seems to get it a bit more than the back and it seems to be mostly around the foot above and below the knees but it's scattered about:


    Here's a closeup of the knee of one leg of those pants above:


    You can see why we say that anyone whose pants don't look like these has never been in poison oak (to any large degree anyway):


    I probably have at least a half dozen pants like these, where I should mark the spots and make a statistical analysis of the most likely spots (there's so much to learn):

  22. #72
    That Waters Guy
    Reputation:
    Join Date
    Jan 2004
    Posts
    605
    Quote Originally Posted by fc View Post
    herbicide? Good intent but this weed is the chuck norris of cockroach weeds.
    Like English ivy and St. John's wort, poison oak has a fairly waxy leaf coating and a woody stem.

    However, I've killed all of them with Bayer brush killer used full strength, enough to wet the leaf but not so much you get much drip off of it.

    The key is making sure you first damage the leaf surface (best) or stems (not as good, but still effective if you're cutting stuff up.) The leaf and stem damage defeats the effectiveness of the waxy leaf coating, which lets the brush killer get into the plant.

    This is triply effective against new growth, since there's less of a waxy coating, more circulation in the plant, and it's easier to damage both leaves and stems.
    Rolland

  23. #73
    mtbr member
    Reputation:
    Join Date
    Jan 2017
    Posts
    162
    Quote Originally Posted by Trackho View Post
    Im generally not that bothered by it unless I have some kind of open scrape that it gets into.
    That's an interesting comment since the urushiol is a rather small molecule which can seep past your skin cells, so, it doesn't need a scrape to get into your skin.

    In fact, I'm not sure what would happen if you dropped the urushiol into cut flesh because the area that the immune system normally reacts in is the "lower layers" of intact skin (aka Langerhans cells).

    Why do you think you'd need to have broken skin to be "infected"?

    Quote Originally Posted by Trackho View Post
    But Ive noticed that with the wet trails--seems like I am getting a mild case on my legs where water/mud gets splashed up. I guess it makes sense that the spores/oils or whatever remain active in rain runoff/mud--anyone else experience this??
    That's an interesting observation, where I've non-scientifically surmised that I get poison oak LESS when it's soaking wet outside, but I haven't tried to study the phenomenon to any great degree.

    One way we could test this without getting the rash is that we could buy two pairs of jeans, and then walk through a section of heavy poison oak on a dry day and then on a wet day and then wash the respective pants.

    Afterward we could count the tell-tale black spots.

    Of course, the other way would be to run naked through the same fields of poison oak, and a dry day and on a wet day, but, since I already took the fc challenge, we'll leave that task for the next intrepid scientist!

  24. #74
    mtbr member
    Reputation:
    Join Date
    Jan 2017
    Posts
    162
    Quote Originally Posted by The Sagebrush Slug View Post
    Like English ivy and St. John's wort, poison oak has a fairly waxy leaf coating and a woody stem.

    However, I've killed all of them with Bayer brush killer used full strength, enough to wet the leaf but not so much you get much drip off of it.

    The key is making sure you first damage the leaf surface (best) or stems (not as good, but still effective if you're cutting stuff up.) The leaf and stem damage defeats the effectiveness of the waxy leaf coating, which lets the brush killer get into the plant.

    This is triply effective against new growth, since there's less of a waxy coating, more circulation in the plant, and it's easier to damage both leaves and stems.
    Take everything I say with a grain of salt because everyone has their preferences who tries to eradicate an entire species off the face of the earth.

    I always have a problem with spraying since the thickets I go through are sometimes hundreds of yards long of vines so thick that you can't possibly get a hand held sprayer to spray the fifty feet you'd need in all directions.

    If I had do damage the leaves, it would take the rest of my lifetime just to spray one hillside of, say, a hundred feet on a side, which is infested with the stuff (tomorrow I'll go out and snap a picture of just such a hillside for you as they abound where I live).

    I mostly rely on mechanical means, which is that I find the thickest vine and follow it to the source and cut, cut, cut, cut, cut, cut, cut, cut, cut, cut, and then pull, pull, pull, pull, pull, pull, pull.

    You can see in a few spots that the cut vines imprinted my clothing:

    Then the only thing that gets sprayed is the inch-thick vine that stayed in the ground.

    I used to manually pull them out of the ground, but it's amazing how long those things go underground, so, I gave up after a while and just cut and pull out the cut parts (which can be fifty feet long).

    Still, I understand what you're saying about spraying the leaves, but I think that's only going to work for the really easy stuff that you could likely pull out with your hands anyway.

    You'll note that I stay away from discussing brand names because they are marketing terms that can have any meaning marketing people want them to have (and often have multiple different chemicals in each formulation).

    Since I do well with glyphosate, I don't use that Bayer stuff, so I googled just now what the chemical is and how it works.

    The Bayer brand seems to market a variety of concentrations of 0.8% to 8.8% (quite a range!) of "Triclopyr, triethylamine salt".


    We have a choice of herbicides, each of which works differently:

    • Glyphosate <== this is what I use
    • 2,4-Dichlorophenoxyacetic acid (aka, 2-4D)
    • 3,5,6-Trichloro-2-pyridinyloxyacetic acid <== this is what you use
    • imazapyr <== you need a license to use it because it lasts for a year


    According to this EPA document the Bayer 8.8% solution has a "6.36% Triclopyr acid equivalent" killing power.

    While a scientific study of the efficacy of the three methods (mostly the first and last) would be easy enough to do, our work will be in finding a decent study which tells us which works best overall (always keeping in mind price/performance considerations at whatever the useful concentrations are).

    This UC document lists a half dozen poison oak killer chemicals, where it says that glyphosate is one of the most effective when proper timing is used and that triclopyr is the most effective of the auxinic solutions (which doesn't include glyphosate so that doesn't help us in comparison purposes).

    Apparently we should be picky with the triclopyr because there are two types where the "Triclopyr ester or triclopyr ester plus 2,4-D ester gives better herbicide absorption into the foliage and is more effective than the Triclopyr amine".

    The good news is that the method I use, which is painting the stumps, can be done with either the glyphosate or with the
    triclopyr, so I'd go with whichever is most effective in a price/availability comparison.



    Last edited by woodrock; 03-03-2017 at 10:34 PM.

  25. #75
    mtbr member
    Reputation:
    Join Date
    Jan 2017
    Posts
    162
    Quote Originally Posted by B1KER View Post
    On another note I never used Tech nu because it was so expensive. But I found that IvyX online for pretty cheap! https://www.pksafety.com/ivy-x-post-...ogsaAjkT8P8HAQ
    That "stuff" looks interesting but we'll have to see what the active ingredients are and what the price/performance ratio is.

    Before I look up what the stuff is made up of and how it works, I'd summarize that there are three classes of "cleaners" that I know of before I look up the ingredients of that specific cleaner:
    1. Expensive stuff (these generally have five active ingredients)
    2. Less-expensive stuff (these generally have four active ingredients)
    3. Cheap stuff (i.e., big surfactant, alcohol, bleach, sand, & maybe small surfactant)

    When you look at the active ingredients and you look at what purpose they achieve, you'll find that, in general, the major difference between #1 and #2 above is the spermicide (aka small surfactant).

    This small surfactant, I think, is a finesse point, in that it certainly has an important function (which is to actually swap out the bound quinone with the spermicide deep inside your inner layers of skin cells).

    But, being a finesse point, I'd guess that the four-part stuff is "almost" as good as the five-part stuff, so my question will be what the chemicals are in your suggested stuff.

    Bear in mind it's my wild-assed claim that the 10¢/ounce individual stuff isn't all that bad either, considering the terrific price differential means you can literally make a single run at Costco and then slather the stuff on.

    It's sort of how the Americans or Russians defeated the German tanks in WWII where the Germans had technical superiority while the Allies had numerical superiority.

    After stating my general bent, I'll dig up tomorrow what I can find on the chemicals, as I'm ready to hit the sack (I wake up before the sun does, but I also go to bed rather early too).
    Last edited by woodrock; 03-03-2017 at 10:19 PM.

  26. #76
    graps the nettle
    Reputation:
    Join Date
    Aug 2005
    Posts
    489
    Quote Originally Posted by woodrock View Post

    I always have a problem with spraying since the thickets I go through are sometimes hundreds of yards long of vines so thick that you can't possibly get a hand held sprayer to spray the fifty feet you'd need in all directions.

    If I had do damage the leaves, it would take the rest of my lifetime just to spray one hillside of, say, a hundred feet on a side, which is infested with the stuff (tomorrow I'll go out and snap a picture of just such a hillside for you as they abound where I live).

    I mostly rely on mechanical means, which is that I find the thickest vine and follow it to the source and cut, cut, cut, cut, cut, cut, cut, cut, cut, cut, and then pull, pull, pull, pull, pull, pull, pull.

    You can see in a few spots that the cut vines imprinted my clothing:

    Then the only thing that gets sprayed is the inch-thick vine that stayed in the ground.

    I used to manually pull them out of the ground, but it's amazing how long those things go underground, so, I gave up after a while and just cut and pull out the cut parts (which can be fifty feet long).

    Still, I understand what you're saying about spraying the leaves, but I think that's only going to work for the really easy stuff that you could likely pull out with your hands anyway.

    You'll note that I stay away from discussing brand names because they are marketing terms that can have any meaning marketing people want them to have (and often have multiple different chemicals in each formulation).

    Since I do well with glyphosate, I don't use that Bayer stuff, so I googled just now what the chemical is and how it works.
    our 85 acre patch of land is affectionately dubbed poison oak acres, and the trial by weeping, oozing fire here corroborates most of what you say. my additional 2c based upon cutting my own trail network through an expansive forest of the stuff is as follows:

    1. when possible, don't build trail through huge thickets of poison oak. it will always come back at some point. but, if you must...

    2. pulling out root systems during the dormant months is absolutely the most effective way to remove large swathes.

    3. spraying glyphosate on green leaves is a good way to get access into heavy foliage. do not bother with the little bottles at home depot, they cost a fortune and are gone almost immediately. go to an ag supply store, or a lawn and turf management place, and buy the highest percentage concentration glyphosate you can buy. i usually end up buying 62.5% mix in 5 gallon increments. this gets diluted down to about 3-4% solution.

    4. timing of glyphosate spraying is critical. do it wrong and you are throwing money away. leaves must be in full green mode, when the photosynthetic engine is pinned. too early (like now), and there is not enough leaf to transport. too late (when leaves begin to redden), and the photosynthesis isn't as rampant. may/june is the high season for deathspray around here (inland monterey county). surfactant is good to add to the mix in order to aid coverage on leaves. adding some high nitrogen fertilizer, like ammonium sulphate, is also highly beneficial, as it helps the plant chug the mix down. areas i sprayed last year and the year before are still dead as dead can be.

    5. BE CAREFUL when spraying. that stuff is highly toxic, will lay waste to other leafy plants just as readily as it will the oak, and is really not the kind of thing you want to breathe or soak in.

    6. woodrock's root painting method works well. either triclopyr or glyphosate. triclopyr mixes are usually considered better at stump and root poisoning than glyphosate, which is predominantly leaf-targeting.

    i use a 6 gallon motorized backpack sprayer, a coated tyvek spraysuit, gloves and a facemask, and generally spray right around sunrise before any kind of breeze comes up. walking steep hillsides with a pack that weighs around 70 pounds full while wearing what is essentially a giant sweatbag is a special kind of crossfit. again, spraying is generally something i reserve for access into big swathes, or for after-the-fact spot control of already cleared areas. for most people, this size spray rig would be overkill, but i have a few miles of trail to deal with that can only be accessed by foot.
    hold my beer...

  27. #77
    fc
    fc is online now
    mtbr founder Administrator
    Reputation: fc's Avatar
    Join Date
    Aug 1996
    Posts
    26,272
    Quote Originally Posted by MtotheF View Post
    our 85 acre patch of land is affectionately dubbed poison oak acres, and the trial by weeping, oozing fire here corroborates most of what you say. my additional 2c based upon cutting my own trail network through an expansive forest of the stuff is as follows:

    ...
    You said, "...when the photosynthetic engine is pinned."

    That could be your new signature.
    IPA will save America

  28. #78
    mtbr member
    Reputation:
    Join Date
    Nov 2009
    Posts
    26
    With all the negative talk about this devil plant I thought what are the positives or pros? I imagine the root system helps reduce erosion on steep terrain but what else?

  29. #79
    That Waters Guy
    Reputation:
    Join Date
    Jan 2004
    Posts
    605

    Good job!

    Quote Originally Posted by woodrock View Post
    Take everything I say with a grain of salt [...] The good news is that the method I use, which is painting the stumps, can be done with either the glyphosate or with the triclopyr, so I'd go with whichever is most effective in a price/availability comparison.
    My comments were intended to be limited to a plant or two you're trying to get off a particular section of trail. I agree that mechanical removal is far superior to chemical, especially if you can follow up with chemical treatment of whatever remains.

    And yes, as you said, I'm using the 8.8% solution of Triclopyr.

    I've only had to pull a field of St. John's Wort once, and I had an excavator, so I used that. But I had to do it twice, several months apart, and am still occasionally following up with hand removal. Stuff's really tough to eliminate.

    I really appreciate your posts on this topic. You clearly know what you're talking about and you do a great job conveying your knowledge. Thanks!
    Rolland

  30. #80
    mtbr member
    Reputation: telemike's Avatar
    Join Date
    Jun 2011
    Posts
    473
    Quote Originally Posted by Empty_Beer View Post
    How do you think the poison oak will be on Hole In The Ground? I'm hoping to ride it when I'm in the area in May.
    The high sierra is now buried under 15 to 20 feet of snow at hole in the ground elevation. I'd be aiming more for July to ride it unless you're on a fatbike.

  31. #81
    middle ring single track
    Reputation: Moe Ped's Avatar
    Join Date
    Aug 2009
    Posts
    3,459
    As a former Los Gatos lad I mostly concur with what Woodrock is saying; with glyphosate (Roundup) I've found it easy to eradicate PO in a couple of seasons. My experience has been that timing isn't all that critical but maybe I've just been lucky. Mid-season, long days and max. sunlight seems to be the ticket. I mix 2 or 3 oz. per gallon of water. (2 oz. is spraying "weeds" in general and 3 oz. if only after more woody stuff like PO)

    But don't use glyphosate (or other herbicides) anywhere but on your own property or if the land manager has explicitly given permission. (Get it in writing) Depending on where it's done "vigilante" spraying could net felony charges.

    Good side of PO? Very good ground cover for holding loose soils together. Doesn't need a lot of water. Native Americans found it made good baskets. Nice fall colors later in the season. Food/shelter for some small critters.

    Disclaimer; I'm in the "lucky"15% of the population not seriously affected by it.
    Content here does not officially represent the CA DPR.

    Windows 10, destroying humanity one upgrade at a time.

  32. #82
    mtbr member
    Reputation:
    Join Date
    Sep 2015
    Posts
    658
    Quote Originally Posted by B1KER View Post
    So just straight rubbing alcohol or do you dilute it at all?
    iirc. It's a 70% solution. It's what we keep on hand to clean our half mask respirators at work. A dust mask essentially.
    Santa Cruz 5010 C
    Surly Crosscheck.

  33. #83
    mtbr member
    Reputation:
    Join Date
    Apr 2006
    Posts
    2
    This tread has been very informative, thanks to everyone who has contributed.

    Sometimes I have come in contact with poison oak and did not know till it was too late, like a couple of days later when the dreaded itching, oozing blisters had appeared. What will help them heal and and reduce the itching?

    For me, it was a 3 week ordeal until I tried Benadryl cream / gel. From what I understand, the urushiol causes an allergic reaction and Benadryl, being a antihistamine helps to reduce this reaction. Since using the Benadryl the healing time for me has been cut to 1-1/2 to 2 weeks and it helps a lot with the itching.

    I have also found that taking an extreme hot shower, letting the water hit the infected area helps to reduce the itching, but while the water is hitting the area there is an intense tingling.

    I'd be interested to know what works for others....

  34. #84
    Just here for the scenery
    Reputation: EddyKilowatt's Avatar
    Join Date
    Aug 2007
    Posts
    344
    I had to extirpate PO from nearly an acre when I bought my place, and found glyphosate plenty effective, either from a pump sprayer at 1% in water with a few drops of dish soap, or painted on vine stumps at 18%. It kills everything green(*) so wait for a windless morning and mind what's behind your target.

    (*)except oleander... spray cut or burn, that plant just don't care
    Greg LeMond for graybeards: "It doesn't get easier... you just go slower"

    If You Can't Fix It, You Don't Own It

  35. #85
    Captain One Lung SuperModerator
    Reputation: JCWages's Avatar
    Join Date
    Jan 2015
    Posts
    3,233
    Quote Originally Posted by Moe Ped View Post
    As a former Los Gatos lad I mostly concur with what Woodrock is saying; with glyphosate (Roundup) I've found it easy to eradicate PO in a couple of seasons. My experience has been that timing isn't all that critical but maybe I've just been lucky. Mid-season, long days and max. sunlight seems to be the ticket. I mix 2 or 3 oz. per gallon of water. (2 oz. is spraying "weeds" in general and 3 oz. if only after more woody stuff like PO)

    But don't use glyphosate (or other herbicides) anywhere but on your own property or if the land manager has explicitly given permission. (Get it in writing) Depending on where it's done "vigilante" spraying could net felony charges.

    Good side of PO? Very good ground cover for holding loose soils together. Doesn't need a lot of water. Native Americans found it made good baskets. Nice fall colors later in the season. Food/shelter for some small critters.

    Disclaimer; I'm in the "lucky"15% of the population not seriously affected by it.
    Usually best results can be had by spraying in the late summer just as the plants are starting to build up winter stores and sucking all that expensive chlorophyll back into their root structures. Herbicide like Glyphosate is designed to inhibit a specific protein production and it does this best when as much of the product is transported from the leaves to the roots as possible. Thus it is important to spray when temps are between approx. 70F-82F and on days with little to no wind. This is increase the time it takes for the chemical to dry and allows more of the chemical to get into the plant.

    For trail systems or other areas that you want clear during summer, you can do an early season spray to knock it back away from pathways but expect to come back with a second application in the late summer. This works really well for blackberry too. On blackberry I usually mix glyphosate with triclopyr although the later requires a permit.

    More information:
    Poison Oak Management Guidelines--UC IPM

  36. #86
    mtbr member
    Reputation:
    Join Date
    Jan 2017
    Posts
    162
    Quote Originally Posted by Moe Ped View Post
    As a former Los Gatos lad I mostly concur with what Woodrock is saying; with glyphosate (Roundup) I've found it easy to eradicate PO in a couple of seasons.
    My kids tell me I'm a genocidal maniac because I am trying to wipe out Scotch Broom, Spanish Broom, and Poison Oak off the face of the earth.

    Each has its own pernicious ways, so you are completely correct in that it takes more than a few seasons to completely eradicate an infestation.

    Quote Originally Posted by Moe Ped View Post
    My experience has been that timing isn't all that critical but maybe I've just been lucky. Mid-season, long days and max. sunlight seems to be the ticket.
    My attitude on timing is "who has time for timing?". There is one thing, and only one thing, which is to get out there and eradicate it. I'm sure all that timing stuff matters, but I'm usually either in it or I'm already covered in dirt from some other task so I figure I'd go kill some species of pesky plant.

    It's like timing for sex. Sure, there might be a way to time it perfectly, nothing wrong with that, but any sex at any time is good sex all the time. That's how I handle my poison oak timing anyway. YMMV.

    Quote Originally Posted by Moe Ped View Post
    I mix 2 or 3 oz. per gallon of water. (2 oz. is spraying "weeds" in general and 3 oz. if only after more woody stuff like PO)
    I'm sure proportions matter, but I'm pretty sloppy with the measurements, where how much I use is more dependent on my mood and what measuring cup I have handy than any science.

    I try to tie a laundry measuring cup to the container but since I leave the container outside, by the end of the season, the cup is often long gone (I've not yet figured out how long the stuff lasts with respect to potency of the concentrated amber-tinted goopy liquid kept outside all year).

    I always have lots of glyphosate lying around as I buy the five-gallon jug of the concentrated glyphosate at that seed store (Pacific?) in between Hamilton and Campbell up against Highway 17. The price is about sixty bucks give or take.

    If you buy glyphosate at any of the hardware stores (OSH, HD, Lowes, Ace, etc.), you'll go broke.

    Quote Originally Posted by Moe Ped View Post
    But don't use glyphosate (or other herbicides) anywhere but on your own property or if the land manager has explicitly given permission. (Get it in writing) Depending on where it's done "vigilante" spraying could net felony charges.
    When I'm on the trail, I have a decimation rule, especially in the rainy season, which is that 10 Scotch Broom plants have to be pulled up (yes, I know decimation is 1/10th, but that's what we call it anyway).

    That's my quota for the ride. You can pull up 10 plants in one sitting, so, I often exceed my quota (did I mention my kids say I'm a genocidal maniac?).

    If I were Trail God, the rule would be "decimation"!
    Everyone on the trail has to pull up 10 Scotch Broom plants, down to the tap root - or - as punishment - I'll remove their bedroom door for a week back at home!

    Quote Originally Posted by Moe Ped View Post
    Good side of PO? Very good ground cover for holding loose soils together. Doesn't need a lot of water. Native Americans found it made good baskets. Nice fall colors later in the season. Food/shelter for some small critters.
    All that is well and good, but my motto is the only good poison oak is a dead poison oak!



    Quote Originally Posted by Moe Ped View Post
    Disclaimer; I'm in the "lucky"15% of the population not seriously affected by it.
    There are people far worse than I am at getting it, and some who never seem to get it, but I'm in the middle where I will almost always get it after working in it, but I spend my efforts at attacking it after the fact (since it's impractical not to be exposed).

    The complexity of the immunology is still befuddling me, but it's not at all like what most people think of with 'antibodies', which is the humoral system.

    This system is the "CMI" or cell-mediated immune system, which is different than the flu virus antibody stuff.

    The antigen here isn't even the Urushiol, as the urushiol itself does nothing bad to your body. So it's a mistake by your immune system. I can explain it in a later post but my problem will be simplifying the explanation because it contains random bits and then the body throws away some of that randomness (which is why people seem to be immune but never really can be sure) and then it attacks the bound quinone with a vengeance, but this post is long enough already.

  37. #87
    middle ring single track
    Reputation: Moe Ped's Avatar
    Join Date
    Aug 2009
    Posts
    3,459
    Quote Originally Posted by woodrock View Post
    When I'm on the trail, I have a rule, especially in the rainy season, which is that 10 Scotch Broom plants have to be pulled up. That's my quota for the ride. You can pull up 10 plants in one sitting, so, I often exceed my quota (did I mention my kids say I'm a genocidal maniac?).

    If I were Trail God, the rule would be:
    Everyone on the trail has to pull up 10 Scotch Broom plants, down to the tap root!


    All that is well and good, but my motto is the only good poison oak is a dead poison oak!
    I'm with you on eradicating Scotch Broom; it's a non-native invasive.

    On the other hand, poison oak is a native and as American as mom and apple pie. Why hate...?

    I don't recall seeing PO and Scotch Broom growing intermixed; perhaps there's a connection?


    Quote Originally Posted by woodrock
    The complexity of the immunology is still befuddling me, but it's not at all like what most people think of with 'antibodies', which is the humoral system.
    When I was a young lad I would get a PO rash as bad as the next kid; I remember 2 or 3 trips to the family doc I had it so bad. Calamine lotion was the go-to.

    By the time I was in high school I was no longer being much affected; my guess is the hormone changes of adolescence altered the chemistry of my immune system. As a side note; as a child I was allergic to cats---post adolescence no more kitty allergy.
    Content here does not officially represent the CA DPR.

    Windows 10, destroying humanity one upgrade at a time.

  38. #88
    orthonormal
    Reputation: andy f's Avatar
    Join Date
    Jan 2004
    Posts
    4,190
    I had zero sensitivity to PO for years, could get it all over myself without breaking out. Then on a ride, I crashed into a woody branch hard enough that it broke my skin. 2-3 days later I had my first ever PO rash. Since then, I have pretty average sensitivity. I don't have to rush to the ER but I will get the typical rash and itching if I don't remove the oils from my skin within a couple hours of exposure.
    The glass is twice as large as it needs to be

  39. #89
    mtbr member
    Reputation: patski's Avatar
    Join Date
    Dec 2005
    Posts
    749
    YMMV but, I'm really, really susceptible to POak, our neighbor coaches a local HS MTB team and he(and the other coaches) swear by this stuff.

    Boericke & Tafel - Oral Ivy

    I used to take Zyrtec for allergies starting about Apr15, I just moved the start date up about 6 weeks.

    I use Oral Ivy and Zyrtec starting about Mar1 through Memorial day.

    I rarely get it bad since I started the Zyrtec/Oral Ivy routine but if I do, Clobetasol(prescription)clears it up in a day or two. I keep a tube in my car.

    The poison oak this year-1051990-topic-poison-oak-back-clobetasol.jpg

  40. #90
    rho
    rho is offline
    Life is strange
    Reputation: rho's Avatar
    Join Date
    Dec 2007
    Posts
    1,878
    holy crap, this thread. This is great! Lot of good info on how to beat the stuff, too. I've always gone with the "get it and suffer" method but I'm a thick headed idiot.


    I can't say I'm looking forward to testing my resistance on the stuff this year, I've been slowly having worse and worse reactions to the stuff as I've gotten older. Not sure how messing with my endocrine system will play into this... but its time to start trying to prevent the rashes by some more post ride cleaning.

  41. #91
    mtbr member
    Reputation:
    Join Date
    Jan 2017
    Posts
    162
    Quote Originally Posted by Moe Ped View Post
    I'm with you on eradicating Scotch Broom; it's a non-native invasive. On the other hand, poison oak is a native and as American as mom and apple pie. Why hate...? I don't recall seeing PO and Scotch Broom growing intermixed; perhaps there's a connection?
    As you are surely aware, all three species favor "disturbed areas" (e.g., the sides of roads, or an area that was cleared years ago, where the brooms have an advantage that they're quite good with carbon and nitrogen in these nutrient-poor franscician soils.

    Being a nitrogen fixer essentially means they "make" their own nitrogen (well, technically, the bacteria do it, but it has the same effect as making the stuff themselves.), which gives them a head start in disturbed areas.

    The brooms are also quite good with carbon, photosynthetically anyway, in that even the stems can make carbon-based sugars from the sun.

    Based on the responses, a lot of us have been dealing with similar infestations of poison oak, so it's not surprising that our experiences are similar. What I like is that people are thinking, and they're not just jumping to old-wives'tales style conclusions.

    That's good, as there is a lot of bad information about poison oak out there, but it doesn't seem to be here, which is a good thing.

    I'm still on crutches after the ACL replacement, but, just for you, I went for a hobble today so that I make good on my promise to show you some shots of what kind of poison oak I deal with (and which others who posted seem to be dealing with).

    They and I have cut trails through the stuff, literally tunneling a man-sized cut (which, as people said, shrinks in size every year as the poison oak encroaches upon it from all sides).


    Here is a portion of a trail I cut maybe three or four years ago, where you can see the piles of still-infectious poison oak vines (and scrub oaks) off to the left.


    Interestingly, studies have been done on how long the poison oak remains infectious in the wild, where in dendrology drawers, they have been proven infections after 100 years.


    But in the real world, it's said the dead debris only remain infectious for five years in wetter climates, and perhaps eight to ten years in our relatively sunny clime.


    While I was out there today, and before I had read Moe Ped's question about whether the brooms co-exist with the poison oak, I snapped this photo of me pulling out a 1/2 inch thick Scotch Broom, where the photo shows the poison oak nearby:


    While pulling the little vines works fine, such as this one springing up along a tree where I cut it's mommy about a year or two ago:


    Pulling is never gonna work on this bigger stuff, which abounds where I live:


    This is a trail, for example, I cut through the poison oak, about five years ago:


    Over time, the poison oak vines have encroached on what was a human-sized path:


    This is a look to the side at that same point, which shows what it looked like before I tunneled through it:


    This is why I said before that the only way "spray" is gonna help here is if we drop it from a fire-bucket helicopter:


    If I'm cutting a tunnel through the stuff, I just pick a straight line, and I start cutting, where, you have to realize, you're surrounded by the stuff, especially when it's weeping from all sides, not only above you and to both sides, but also a foot deep under your very feet.


    If I'm trying to eradicate a patch such as these (which I will eventually tackle), my strategy is to undermine the main roots by cutting parallel checkerboard patterns about 20 or 30 feet apart:


    I guess I could just bring in heavy equipment to rip out the entire hillside some day, and plant a vineyard in its place!

  42. #92
    mtbr member
    Reputation:
    Join Date
    Sep 2015
    Posts
    658
    i learned a lot from this thread...thanks.
    Santa Cruz 5010 C
    Surly Crosscheck.

  43. #93
    mtbr member
    Reputation: rzims's Avatar
    Join Date
    Sep 2005
    Posts
    1,097
    awesome thread with lots of great info.
    I've been buying IvyX wipes online and using those to wipe all exposed areas after a ride and before getting home to a shower with lots of soap and a washcloth for scrubbing myself red....
    Seems to work although I'm glad to know I no longer have to suffer through a cold shower - the "closed pores" thought made sense to me but now I understand.

    I usually get it a couple of times a year and it's when I don't realize I've been exposed...

  44. #94
    fc
    fc is online now
    mtbr founder Administrator
    Reputation: fc's Avatar
    Join Date
    Aug 1996
    Posts
    26,272
    Quote Originally Posted by Boomchakabowwow View Post
    i learned a lot from this thread...thanks.
    Right on. It's a goldmine of info this year. That's why we start dem threads.

    And we're gonna need it!

    Perhaps the best cure to poison oak is knowledge. Be very observant these days and remember where the poison oak lives in your local trail. It is useful knowledge for years to come.
    IPA will save America

  45. #95
    mtbr member
    Reputation:
    Join Date
    Jan 2017
    Posts
    162
    Quote Originally Posted by fc View Post
    Perhaps the best cure to poison oak is knowledge.
    I agree with you that knowledge is what matters.
    Luckily, this crew, including you, seems to know their poison oak well.

    I had promised a description of the "infection" process, so I'll start with an off-the-cuff description of poison oak "chemistry", but I ask the real chemists out there to pitch in to fill in the gaps in our knowledge.

    Let me know if this off-the-cuff description makes sense, because there are some parts that I don't completely understand (like what process oxidizes the catechol in the skin for example or where exactly does the diffusion occur, whether it's membranes or between cells, etc.).

    As I tried to graphically show in the fc forearm challenge, the urushiol is, technically, not on the outside of the plant, but inside the plant, specifically in the phloem, where there are resinous canals that contain an oily resinous sap.

    You can graphically see this, by the way, because the phloem is just under the bark, where in my previous photos, you could see the black oxidized urushiol stains on my clothes exactly mirrored the phloem location where the nasty sap is confined.

    In that oleoresinous sap of the plant is a set of phenolic catechols collectively called urushiol. A phenol is a six-carbon benzene ring with at least one hydroxyl (OH) group on it. A catechol is a benzene ring with two hydroxyl groups on it.

    NOTE: Because of the level of bonding with the electron shell, it "sounds" like an alcohol, but apparently it's not an alcohol (where are the chemists when you need them?).

    Since there's a benzene ring in the middle - it's an aromatic.

    There is also an alkyl group (single, double and triple-bonded), so, maybe the alkyl group gives it the oily consistency? Dunno yet. Need chemists to help out here!

    It sure sounds like an "oily aromatic alcohol-like thingy" to me.

    The poison-ivy variety of this thingy "mostly" consists of four different chains of 15 carbon atoms each, while the poison-oak variety mostly comprises four different chains of 17 carbons each. But that 15/17 distinction doesn't seem to make any difference in the immune response, as far as I can tell to date (but I need to research that further).



    What happens inside your skin is that the funny-looking thing above is "oxidized" (I'm still trying to figure out what oxidizes it) to a quinone, which is not an aromatic and which no longer has the hydroxyl groups.

    It is not obvious to me why your body doesn't react to the non-oxidized aromatic, nor, what oxidizes it to the qunone, but your entire immune reaction is to the quinone, and not to the catechol.

    Since this post is getting long, I'll wrap up the "chemistry" part of the description, but I ask that any chemists out there help us out by explaining the significance, chemically of the poison oak molecule's various parts (I'll cover biochemistry separately).

  46. #96
    mtbr member
    Reputation:
    Join Date
    Jan 2017
    Posts
    162
    Quote Originally Posted by fc View Post
    Perhaps the best cure to poison oak is knowledge.
    The first thing to note of importance, immunologically, is that both the catechol and the quinone, chemically, are completely harmless to the human body, in and of themselves.

    So this is not a case of your body trying to get rid of a harmful chemical.

    It's a case of your body trying to get rid of a chemical that it doesn't know if it's harmful - so it errs on the assumption that it is (more about that later).

    The second thing to note is that antibodies aren't involved.

    So forget everything you know about how vaccines work!
    Your cells are doing the mediating; not your humoral antibodies.

    That means a whole bunch of things that are different from what people generally know about "infections", which is why there are so many old wives' tales about poison oak rashes.

    For example, CMI strongly implies that repeated contact will NOT give you immunity. (I need to research that statement better though, so take it with a grain of salt.)

    As far as I can figure out, each contact should be "technically" worse than the previous contacts, because your cellular immune system "memory" gets 'better and better" at it, but the reality is that no two situations are ever going to be exactly alike in that the amount of urushiol you get is different, whether those slow-moving cells bump into the quinone is a random thing, and even the current state of your immune system seems to fluctuate over time.

    But what all that means is that I take with a huge amount of skepticism what many people say about how they used to get rashes before - but after doing whatever, now they've desensitized themselves.

    So, let's just say that your response may fluctuate - but it's gonna be in the general range of a typical dose-response curve specific to your gene expression curve (since the cell mediated immunity process causes genes to express themselves).

    It's important to note that a funny thing about cellular stuff versus humoral antibody stuff is that cells are relatively slow moving things.

    So this is always gonna be all about a delayed response.

    You're not gonna get a reaction in just a short time.
    It might take one or two days to start, and a week or two to complete.
    Then it takes time to heal.

    Moving on, let's assume anywhere from as little as two micrograms to fifty micrograms of an oily polymerous sap from the phloem leaks out, and gets on your bare skin.
    And, for now, let's assume you have been prior sensitized, and that your immune system elicits a response.

    If you wash now, before the urushiol is "bound" to a cell membrane, you will probably wash it off easily; but once it's bound to a cell membrane, it's more difficult to merely wash off.

    The chemists out there might be able to suggest a good solvent, but, it's clear given the nature of the sap that treatment is best that begins at once, by washing off the oleoresinous oil before the urushiol in the sap is oxidized and bound to your langerhans cells, and after that, treatment consists of sloughing off skin cells to exchange a surfactant for the bound quinone, and after that, rougher action with the skin cells and a surfactant with a better affinity for the bound quinone, and after that, you have to start using corticosteroids (i.e., hormones, e.g., hydrocortisone, aka cortisol, prednisolone, prednisone, dexamethasone, etc.) which diminish the immune response by affecting gene expression as a sort of chill-out "sedative" for the immune system. But I get ahead of myself.

    The point is, if you don't immediately remove the sap, it doesn't take long before that funny-looking urushiol in the oleoresinous sap immediately begins to wick past the stratified squamous epithelial cells by molecular diffusion, which takes something on the order of fifteen minutes to get past the Berlin Wall of the outer skin squamous layers.

    Up until now, we needed help from the chemists but moving forward, we're gonna need the biochemists to pitch in to explain what's going on.

    What I know is that the urushiol seeps past your outer epidermis by some "wicking" or "diffusion" process.

    Down, down, down it goes, through the various external layers of your skin.

    In the deeper layers of the skin the urushiol is metabolized (aka oxidized) to a benzoquinone (as explained in the prior post).

    As we described earlier, that benzoquinone looks like a benzene ring with two oxygens, but the carbon-to-carbon bonds are conjugated (and not aromatic).
    The quinone binds to proteins in the membranes of dendritic epidermal white blood cells called Langerhans cells.

    Up until now, it was sheer chemistry; but once it's bound to the dendritic white blood cell, everything changes.

    First off, washing it off won't be as easy as we'd like.
    And, now we're going to journey into the center of cell mediated immunology.

    I'll try to explain the cell mediated immune process specific to poison oak, but here's a simplified diagram of what we're going to be dealing with:

  47. #97
    mtbr member
    Reputation:
    Join Date
    Jan 2017
    Posts
    162
    Quote Originally Posted by fc View Post
    Perhaps the best cure to poison oak is knowledge.
    Are you ready for the fun stuff?

    Do you see in the diagram in the prior post the MHC (major histocompatibility complex) on the Langerhans cell?

    That's the thing that causes the quinone to bind to the Langerhan's cell.

    The Langerhans cell "looks different" to your immune system with the quinone bound to it, just like you would look funny if you had a clown nose stuck to your face, and, by looking funny, you cause the immune system to elicit a "laughing" response (of sorts).

    Once the quinone is bound to the Langerhan's cell, it's "activated" where it's job is now to migrate to the nearest lymph node circus where all the fun stuff is supposed to be.

    In the circus are clones of special white blood cells variously named effector T-cells or helper T-cells, some of which are already primed to have a special affinity for your specific clown-nosed Langerhan's cell.
    (Separately, we'll take up where those specific-to-the-quinone helper T-Cells came from in the first place - but I'm trying to keep this simple.)

    One important thing to note is that there is a certain randomness to cell mediated immunity. So luck plays a role.

    If you're really lucky today, no effector T-cell that has been primed for the bound quinone will bump into your activated Langerhan's cell before the quinone is absorbed into the cell, and nothing bad will happen to you today.

    The Langerhan cell will eventually engulf the quinone, and then it will die in a couple of days, and that will be the end of our story.

    Of course, if you've never been exposed before, then you can't have any of this reaction, so you're again, just randomly lucky that you haven't yet been exposed to poison oak, so, the activated Langerhan cell doesn't elicit any response in the lymph node.

    Or, you could have been exposed, but you're one of the lucky people whose thymus recognized the quinone analog as "self", and therefore no immature T cells got past your thymus, and you won't have any primed T cells to react to the activated Langerhans cell.

    Even if you have been exposed before, and even if your thymus didn't recognize the quinone analog as self, today could just be your lucky day, like when you run a metering light and there's no cop anywhere in sight - where there just didn't happen to be any primed effector T-cells in the lymph node to mate with the activated Langerhan's cell.

    Maybe you're really lucky (so to speak), and you have a t-cell-related immunodeficiency disorder, where your immune response is less active due to decreased T-cell counts.

    What I'm trying to outline is that there is a certain measure of chance involved, although the larger and more repeated the dose, the less you will be able to rely on chance luck in not having an immune response.

    If, perchance, today isn't your lucky day, then an appropriately sensitized effector T-cell will see your funny-looking Langerhan's cell, and bind to it in a complex mating dance.

    After that mating ritual, the effector T-cell produces clones of itself and exudes small signal-flag proteins cytokines (cell movers). Since they're produced by a lymphocyte, we call these specific cytokines lymphokines.

    These rather small signal-flag lymphokyne proteins attract the attention of other white blood cells, so, the explanation below starts getting confusing, I know.

    Some of the white blood cells release cytolytic enzymes and protein toxins called perforins which are little anti-personnel grenades that act on all cells in the vicinity, including the langerhan cell with its membrane-bound quinone.

    Another of those white blood cells that are attracted by the lymphokynes are particularly hungry monocytes which are activated by the lymphokynes which turns them into random-acting macrophages who randomly engulf anything in the vicinity.

    Yet another of those white blood cells that are attracted by the lymphokines are especially murderous cytotoxic thugs called Killer T-cells, where these killer thugs seem to come out of the alleys of the lymph node, already armed with the quinone receptors on their outsides (where they got those arms is the subject of another conversation).

    The point is that the macrophages and perforins are untargeted, while T-cells are targeted, so during that crucial first 24 to 48 hours, there's a mix of deadly randomness and murderous purpose involved in wiping out any vestige of the bound quinone in your system.

    A key point here is that some of this stuff is completely non selective. so there's always gonna be collateral damage.

    That means anything within the blast radius is also destroyed, including skin, blood, lymph, and nerve cells.

    Cellular fluids ooze out of the destroyed cells where the remaining undamaged cells have to hold back the blisters of ooze.

    Vasodilation brings in more blood flow to the area, causing a redness in the battle zone in linear streaks and patches.

    I haven't figured out the itching yet, but it could be as simple as nerve damage causing a pain, not like a headache or broken bone, but more like a superficial tingling sensation we perceive as itching.

    If anyone knows why the itching occurs, please let us know because I haven't figured that out yet.

    In the end, the funny-looking clown-nosed quinone-bound langerhans cells are no more and everything slowly gets back to normal but it may take one or two weeks to rebuild that which was damaged.


  48. #98
    mtbr member
    Reputation: dirtyBob's Avatar
    Join Date
    Jun 2005
    Posts
    135
    Quote Originally Posted by EddyKilowatt View Post

    There's video online by a guy who uses something like sticky axle grease to illustrate his view of the spreadability and tenacity of the stuff, and the need for soap and/or solvent plus vigorous scrubbing to remove it.
    that vid rules! i do trail work in addition to riding around "the evil weed" all the time. had cortizone shots for some nice cases in the past too. after watching that video, now i just keep mechanic's soap (the orange stuff with grains of pumice) in my shower. anytime i know i went through some oak, i just lather up in a lukewarm shower after i get home. works amazingly well.

  49. #99
    middle ring single track
    Reputation: Moe Ped's Avatar
    Join Date
    Aug 2009
    Posts
    3,459
    It's "Doctor woodrock" from now on.
    Content here does not officially represent the CA DPR.

    Windows 10, destroying humanity one upgrade at a time.

  50. #100
    mtbr member
    Reputation:
    Join Date
    Jan 2017
    Posts
    162
    Quote Originally Posted by dirtyBob View Post
    that vid rules! i do trail work in addition to riding around "the evil weed" all the time. had cortizone shots for some nice cases in the past too. after watching that video, now i just keep mechanic's soap (the orange stuff with grains of pumice) in my shower. anytime i know i went through some oak, i just lather up in a lukewarm shower after i get home. works amazingly well.
    You bring up two fantastic points, which is that there are TWO places to get rid of the stuff on/in your skin.
    A. The outside of your skin (before it penetrates), and,
    B. The inside of your skin (after it has had time to penetrate).

    There's also the matter that your clothes and bike have the stuff on it, so we also need to figure out how to clean them too.

    Each of these has to be taken individually, as you have.
    1. The outside of your skin has the sap, which seems to be sort of like sticky axle grease, but I really wish we could find out more about the composition of the sap, and how much of it actually contains urushiol, and what the other oily sticky is, because it's critical to "know your enemy" and how to get rid of it.

    2. Once inside your skin, I think you're on target with the abrasive soap. I generally leave the abrasives (toothpaste, for example) for the next day, but, it makes a lot of sense to abrade off any skin that contains activated langerhans cells. So your approach fits what we know about the immune system's reaction, which is good, because that means your approach is based on logic.

    3. For clothes, I've found empirically, that a standard washing-machine cycle suffices. Have others found that to be the case?

    4. For equipment like bikes and tools, I generally do nothing, but, if I were to suggest a wash, it would be a basic garden hose and detergent approach. Does that seem appropriate to get rid of the sap? (We know the sap is infectious for five to ten years outdoors, and far longer indoors, so, this is an important question).

    5. One odd component is leather stuff. I don't wash my boots or gloves. I do quarantine them, but they're hard to wash (especially the gloves). I have a pet theory, not at all confirmed, that maybe, just maybe, the animal skin, even dead, somehow, "inactivates" the urushiol? Can that be? What I find is that my gloves are black with oxidized urushiol but they don't seem to be infectious, even though they were slathered in sap. Does leather confer some type of inactivation that cloth doesn't?

    There are so many more questions than answers, so I'm hoping someone where can help with those answers for everyone to benefit from the tribal knowledge!

Page 2 of 4 FirstFirst 1234 LastLast

Similar Threads

  1. Poison Ivy & Poison Oak Warning.
    By DIRTJUNKIE in forum Passion
    Replies: 9
    Last Post: 05-21-2015, 04:05 PM
  2. Tis the season: Poison Ivy & Poison Oak Warning.
    By DIRTJUNKIE in forum General Discussion
    Replies: 6
    Last Post: 05-11-2015, 03:33 PM
  3. poison ivy
    By Carl1977 in forum General Discussion
    Replies: 15
    Last Post: 08-23-2014, 07:42 PM
  4. Poison ivy / oak
    By Corbinworks in forum Southeast/Midsouth - GA, TN, AL, FL, MS, LA, AR
    Replies: 17
    Last Post: 06-15-2012, 04:25 PM
  5. POO !!! (Poison Oak)
    By old'skool in forum General Discussion
    Replies: 1
    Last Post: 07-02-2011, 12:16 PM

Members who have read this thread: 401

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •