Thermal paste problem- Mtbr.com
Results 1 to 36 of 36
  1. #1
    meep meep !!!
    Reputation: Road_Runner's Avatar
    Join Date
    Mar 2009
    Posts
    113

    Thermal paste problem

    Morning all, I've got a quick question for you:

    I'm trying to remove these LEDs on their stars from an aluminium baseplate which is part of a drop in that I got from DX



    However the little beggars are refusing to budge because they are very firmly fixed down with white thermal paste.

    I have tried heating it, freezing it and applying generous amounts of isopropyl alcohol and acetone (propanone) but all to no avail.

    Does anyone know of a non-destructive method of unsticking them, or will I have resort to more drastic methods? I would like to recover the LEDs on their stars intact if possible.

    Thanks in advance.

  2. #2
    Five is right out
    Reputation:
    Join Date
    Sep 2006
    Posts
    3,174
    Even with the Arctic thermal adhesive product, I've found that a sharp, short knock can shatter the adhesive. That's probably the more 'drastic' measure that you mention, but it's worked for me. Runs a fair risk of damaging the LEDs though.

  3. #3
    mtbr member
    Reputation: Goldigger's Avatar
    Join Date
    Nov 2009
    Posts
    1,670
    How long did you freeze it for?
    I would freeze it over night then put the heat sink in a vice and knock them off with a screwdriver..
    I've always popped June off with a screw driver...but I only had a really thin layer of epoxy

    Or you could try freezing it then applying sudden heat...

  4. #4
    meep meep !!!
    Reputation: Road_Runner's Avatar
    Join Date
    Mar 2009
    Posts
    113
    Thanks for your input chaps.

    Womble; the thermal paste has set firmly, but is still a bit rubbery and flexible so I don't think that it will be possible to shatter it, unfortunately.

    GD; I froze the baseplate overnight and tried the vice + screwdriver method but there is limited room for manoeuvre in there and they still weren't budging, so I gave up.

    Well, I guess I'll have to get the hot air gun out and desolder the LEDs from their stars later today, unless someone comes up with a better plan between then and now.

    Have ordered some replacement bare stars from KD just case and after I've desoldered the LEDs I will be free to use extreme brutality to extract the old stars + thermal paste.

  5. #5
    Light freak
    Reputation: scar's Avatar
    Join Date
    Jun 2005
    Posts
    3,015
    Use a chisel type exacto knife blade Widget Supply X-ACTO X218 5pc No 18 Heavyweight Chiseling Knife Blade

    Place the backside of the knife blade against the base plate and the angled edge against the bottom side edge of the star. Give the exacto knife a slight rap with a hammer and the star will pop right off. I would start with the center LED and then that would give some more room to work with for the outer ones.

    Not sure exactly what type of adhevive you are using but it works like a charm with Artic Silver Thermal Adhesive.

    ****

  6. #6
    meep meep !!!
    Reputation: Road_Runner's Avatar
    Join Date
    Mar 2009
    Posts
    113
    Quote Originally Posted by scar View Post
    Use a chisel type exacto knife blade Widget Supply X-ACTO X218 5pc No 18 Heavyweight Chiseling Knife Blade

    Place the backside of the knife blade against the base plate and the angled edge against the bottom side edge of the star. Give the exacto knife a slight rap with a hammer and the star will pop right off. I would start with the center LED and then that would give some more room to work with for the outer ones.

    Not sure exactly what type of adhevive you are using but it works like a charm with Artic Silver Thermal Adhesive.

    ****
    Thanks scar, have ordered some from Amazon UK and will try your method when they arrive.

  7. #7
    mtbr member
    Reputation: HuffyPuffy's Avatar
    Join Date
    Jun 2008
    Posts
    890
    I believe (but am not an expert) that these thermal adhesives generally use Silicone. Since you say it still has a rubbery texture even though it is well cured, seems to back that up. In the past I have been lucky using razor blades to remove these (like the one you ordered), but I see your heatsink has a ledge to deal with that will make it difficult to get under it.

    Thinking that removing silicone may be useful info for myself in the future, I googled "removing silicone" and found a number of ideas. One is WD40 (and a cold beer or Pepsi while you wait), or some other petroleum products were mentioned, and if you google "silicone remover" there are quite a few commercial products. One thing to consider though is that the domes of the LED's are probably also silicone.

  8. #8
    mtbr member
    Reputation:
    Join Date
    Jan 2009
    Posts
    55
    Perhaps using a strong pair of needle-nose pliers to sort of twist them? Looks like you can get a good grip with the two screw mounts on either side.

  9. #9
    meep meep !!!
    Reputation: Road_Runner's Avatar
    Join Date
    Mar 2009
    Posts
    113
    I tried the twisting with pointed pliers trick, which has worked in the past, but not on this particular stuff - all that happens is the soft aluminium of the stars gets chewed and as they are 12mm stars there isn't a lot of metal there to get any degree of leverage with.

    The domes are hard plastic, rather than soft silicone, so I might give the WD40 a go later (and the beer option as well).

    Thanks for all the helpful suggestions guys, I will get them off somehow and when I do I'll let you know how I did it.

  10. #10
    mtbr member
    Reputation:
    Join Date
    Sep 2009
    Posts
    21
    Quote Originally Posted by goldigger View Post
    how long did you freeze it for?
    I would freeze it over night then put the heat sink in a vice and knock them off with a screwdriver..
    I've always popped june off with a screw driver...but i only had a really thin layer of epoxy

    or you could try freezing it then applying sudden heat...
    3...........

  11. #11
    mtbr member
    Reputation:
    Join Date
    Sep 2009
    Posts
    21
    good ideas

  12. #12
    mtbr member
    Reputation:
    Join Date
    Sep 2009
    Posts
    21
    67 times already

  13. #13
    meep meep !!!
    Reputation: Road_Runner's Avatar
    Join Date
    Mar 2009
    Posts
    113
    Hope the minotaur gets hold of you.

  14. #14
    mtbr member
    Reputation: troutie-mtb's Avatar
    Join Date
    Sep 2007
    Posts
    3,062
    My 2 Cents worth

    How hot have you had them my experience is get the part really ouch hot and the epoxy lets go easy

    dont worry about the leds as reflow soldering goes to 220 c without damage.

    tip wear good gloves and sharpen a screwdriver up

  15. #15
    mtbr member
    Reputation: Goldigger's Avatar
    Join Date
    Nov 2009
    Posts
    1,670
    Quote Originally Posted by labyrinth248 View Post
    67 times already

  16. #16
    mtbr member
    Reputation: yetibetty's Avatar
    Join Date
    Dec 2007
    Posts
    1,781
    At least it was longer than this one:

    Quote Originally Posted by labyrinth248 View Post
    3...........

  17. #17
    meep meep !!!
    Reputation: Road_Runner's Avatar
    Join Date
    Mar 2009
    Posts
    113
    Quote Originally Posted by troutie-mtb View Post
    My 2 Cents worth

    How hot have you had them my experience is get the part really ouch hot and the epoxy lets go easy

    dont worry about the leds as reflow soldering goes to 220 c without damage.

    tip wear good gloves and sharpen a screwdriver up
    Well, I just stuck the heat gun on it @ 150 C for about 5 minutes and try as I might I couldn't prise the star free, but I did manage to inadvertently prise the LED away from the star.



    It pinged halfway across the room and I had to spend a couple of minutes finding it on the carpet, but I'm glad to report that it is none the worse for the experience and it still works when I pass 3.3v through it .

    Seriously though, that Chinese goop that they put on it has some fairly amazing adhesive properties. I take my hat off to them for it, but I only wish that they'd put something cheaper on my particular unit.

    I'm going to leave it alone now until my new Xacto knife and blades arrive, then try it Scar's way. I've tried brute force methods which didn't work and now it's time to get a bit surgical with it so will keep you posted about how it all goes.

  18. #18
    A waste of time it is is
    Reputation: emu26's Avatar
    Join Date
    Jun 2008
    Posts
    3,456
    road runner, it's a pain but they can be pushed off from the back. I'm presumming it is similar white "silicone goop" that DX used on the pills I salvaged. The problem you'll have is that you'll need to drill a small hole through the slug but not so deep it goes into the star. Drill a hole where there is no star first so that you can see how thick the slug is. When you are drilling behind the star do it close to one edge so that you can push up one side first.

    The other method that will work is using fine fishing line, but the lip on the slug will make it difficult to get it going. Clamp the slug in the vice. There will usually be one edge / corner of the star that you can just get the line under. do your best getting it under and then "saw" the line from side to side. Slow going and you'll break a piece or two but it will eventually "cut" the star off the slug. I suggest wrapping either end of the line around some screwdriver shafts or something similar, otherwise it will cut into your fingers long before it has cut through the silicone.

    Good luck.

    BTW I don't like the twist from above with pliers method, I think you are at great risk of them slipping and then gouging the dome.

  19. #19
    mtbr member
    Reputation: troutie-mtb's Avatar
    Join Date
    Sep 2007
    Posts
    3,062
    I would like some of that glue wonder whatnit is called. and where it can be had

  20. #20
    mtbr member
    Reputation: yetibetty's Avatar
    Join Date
    Dec 2007
    Posts
    1,781
    How about using a feeler gauge as a blade, they are very flexi and could help get into the tight space.

  21. #21
    mtbr member
    Reputation: Goldigger's Avatar
    Join Date
    Nov 2009
    Posts
    1,670
    Quote Originally Posted by troutie-mtb View Post
    I would like some of that glue wonder whatnit is called. and where it can be had
    Road runners got some, sure you can have some if he can get it off the stars

  22. #22
    mtbr member
    Reputation:
    Join Date
    Oct 2009
    Posts
    373
    chisel and hammer, should do.
    going to be a mess, and you'd need to remove all of it, and re-polish.
    would prefer screws for upgradability and maintenance .

    let me know your favorite screws for the star boards , email, please
    think, a bunch of DIY parts, be cool to have .
    cheers, Rob

  23. #23
    mtbr member
    Reputation:
    Join Date
    May 2005
    Posts
    3,832
    Quote Originally Posted by rschultz101 View Post
    would prefer screws for upgradability and maintenance .

    let me know your favorite screws for the star boards
    I used screws on the first couple of lights I built for those reasons. After that, I started gluing them on. I changed methods because I found that I never upgraded a light where I wanted or was able to re-use the housing and after several lights only one LED has failed prematurely. Also the screws were another obstacle that required cutting clearance for with some optics holders.

  24. #24
    meep meep !!!
    Reputation: Road_Runner's Avatar
    Join Date
    Mar 2009
    Posts
    113
    Quote Originally Posted by Vancbiker View Post
    I used screws on the first couple of lights I built for those reasons. After that, I started gluing them on. I changed methods because I found that I never upgraded a light where I wanted or was able to re-use the housing and after several lights only one LED has failed prematurely. Also the screws were another obstacle that required cutting clearance for with some optics holders.
    I couldn't agree with you more. Also, as I'm making two lights with two of these drop in units, using screws would involve drilling & tapping two holes per LED, times six LEDs per baseplate, times two lights, making twenty four seperate drilling & tapping operations in total.

    And the alignment of the holes would have to be spot on every time to match with the LED holes in the reflectors, or the whole thing would start to go pear-shaped from the word go.

    Life is simply just too short to get involved with all that kind of procedure, IMO

    Additionally, if I used Emu's undermining method to remove the present LEDs then the baseplates would end up looking like Swiss cheese by the time it was all done.

    Keep it simple stupid is my philosophy and I intend to stick with it at all times.

  25. #25
    mtbr member
    Reputation: mattthemuppet's Avatar
    Join Date
    Jul 2004
    Posts
    2,374
    I dunno, I like screwing LEDs down. I'm more confident of getting good even pressure on the LED plus I've upgraded at least 3 of the lights I've built so far with brighter LEDs (mostly XP-G to XM-L). I think that the key thing for me is that it takes me such a long time to build one housing, that it's easier to upgrade the LED than it is to make a new light, although I realise that that's the opposite of most people on here I also max out (for similar reasons) on 2 LEDs a light, so 4 drilled and tapped holes isn't particularly onerous.

    as for getting those LEDs off, the way I've always got chipset heatsinks and the like off has been with a screwdriver, levering and twisting underneath, occasionally with a hammer. If all else fails, I'd go with Rob's method. Hammer a sharpened screwdriver under the edge of the centre LED, lever and twist, repeat with the others. You want to break the bond over its shortest distance (star to housing) not the greatest (along the star).

  26. #26
    meep meep !!!
    Reputation: Road_Runner's Avatar
    Join Date
    Mar 2009
    Posts
    113
    Well the LEDs are going to be screwed down indirectly anyway, as the five holes in the baseplate allow screws to pass through and thread into the reflector unit which is then clamped down on top of the LED stars on the baseplate. One hole is left screwless to allow the wires to pass through and you need to put isolator rings on top of the stars to prevent short circuits because the reflector unit is metal.





    The example in the pictures has four screw holes rather than five, and five reflectors rather than six, but the principle is exactly the same.

    And I'm still holding on for the Xacto knife and chisel blades to arrive. Got an email from Amazon to say that they have been dispatched today, so hopefully they should arrive tomorrow.

  27. #27
    A waste of time it is is
    Reputation: emu26's Avatar
    Join Date
    Jun 2008
    Posts
    3,456
    Quote Originally Posted by Road_Runner View Post
    Additionally, if I used Emu's undermining method to remove the present LEDs then the baseplates would end up looking like Swiss cheese by the time it was all done.
    You only need one hole per star for this to work and I was under the impression it was the leds and stars you wanted to salvage, not the base

  28. #28
    meep meep !!!
    Reputation: Road_Runner's Avatar
    Join Date
    Mar 2009
    Posts
    113
    Quote Originally Posted by emu26 View Post
    You only need one hole per star for this to work and I was under the impression it was the leds and stars you wanted to salvage, not the base
    No, both, but at the moment it's the baseplate that is of more immediate use to me.

    Thanks for your input and I didn't mean to sound dismissive of your idea, so I hope it didn't come across that way.

  29. #29
    A waste of time it is is
    Reputation: emu26's Avatar
    Join Date
    Jun 2008
    Posts
    3,456
    No problems at all.

    Did you search DX to see if you could by the base on it's own? Often you can but they are hidden away, I found that out the hard way after I had bought my pills and taken the time to get the stars off them and then modding the base.

    Good luck with it

  30. #30
    meep meep !!!
    Reputation: Road_Runner's Avatar
    Join Date
    Mar 2009
    Posts
    113
    Quote Originally Posted by emu26 View Post
    Did you search DX to see if you could by the base on it's own? Often you can but they are hidden away, I found that out the hard way after I had bought my pills and taken the time to get the stars off them and then modding the base.
    Yes, you can now get the complete bare units from KD here, but a couple of months ago all that was available was these from DX, so that's what I got, and got two of them.

    So next I need to remove the 6 XPE Q5s from each unit and replace them with my own choice of LEDs, but this is proving to be a bit tricky at the moment.

    However, I never walk away from a challenge and I will get those little so-and-so's out one way or another and will absolutely not buy the much cheaper bare units from KD as well if I can possibly avoid it.

    And then afterwards I will have 12 spare XPE Q5s that I didn't really want anyway, and for which I have no particular use at the moment, and which have cost me an extra $32.44 that I really didn't want to spend at all.

    Oh well, such is life........

    Can't wait to try Scar's no 2 knife chisel trick on 'em, though. Please let Mr Postman bring these items tomorrow so I can get this project moving again. Pretty, pretty please.

  31. #31
    mtbr member
    Reputation: mattthemuppet's Avatar
    Join Date
    Jul 2004
    Posts
    2,374
    the resting place of all my old LEDs is in dome lights for my car or rear bike lights with some scavenged red plastic. I'm especially proud of my twin LED rear dome light in my Focus wagon - one LED points down into the trunk/ boot, the other points out so I'm not continually tripping over my bike at the end of night rides or losing the children in the supermarket parking lot.

    so, no LED ever really dies, it just gets used for something else..

  32. #32
    Light freak
    Reputation: scar's Avatar
    Join Date
    Jun 2005
    Posts
    3,015

    Did you ever get your xacto knife blades?

    Any luck?



    ***

  33. #33
    meep meep !!!
    Reputation: Road_Runner's Avatar
    Join Date
    Mar 2009
    Posts
    113
    Quote Originally Posted by scar View Post
    Any luck?



    ***
    After a long wait, and an exchange of correspondence with the Amazon seller, my Xacto chisel blades finally arrived today and I shall be setting about extracting those awkward stars tomorrow night.

    Can't do it tonight, or build my Goldigger 3x XML light, because I am currently away from home for romantic reasons.

    I'll keep you posted on how it all goes.

  34. #34
    mtbr member
    Reputation:
    Join Date
    Jan 2006
    Posts
    23
    "I'll keep you posted on how it all goes. "


    The Exacto's or the Romance?

  35. #35
    meep meep !!!
    Reputation: Road_Runner's Avatar
    Join Date
    Mar 2009
    Posts
    113
    Just the Xacto stuff I think, this isn't that kind of website.

    Anyway, Scar's method worked out a treat and I'm very grateful to you sir.

    It's amazing what you can do if you have the right tools!


  36. #36
    Light freak
    Reputation: scar's Avatar
    Join Date
    Jun 2005
    Posts
    3,015
    Very cool


    ***

Similar Threads

  1. Thermal Paste options
    By Goldigger in forum Lights DIY - Do It Yourself
    Replies: 8
    Last Post: 10-17-2010, 01:25 PM
  2. Thermal Grease?
    By ozlongboarder in forum Lights DIY - Do It Yourself
    Replies: 2
    Last Post: 07-15-2010, 10:09 PM
  3. Thermal Protection
    By tamen00 in forum Lights DIY - Do It Yourself
    Replies: 2
    Last Post: 08-21-2009, 05:00 PM
  4. mtb trails in thermal-indio
    By dtrancex in forum California - Socal
    Replies: 1
    Last Post: 03-07-2009, 01:37 PM
  5. Thermal Calculations
    By G_Mozz in forum Lights DIY - Do It Yourself
    Replies: 17
    Last Post: 09-18-2008, 04:51 AM

Members who have read this thread: 0

Posting Permissions

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

THE SITE

ABOUT MTBR

VISIT US AT

© Copyright 2020 VerticalScope Inc. All rights reserved.