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  1. #1
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    Powder coating RS dart 3 Magnesium Lowers

    I'm hopeful that someone on mtbr might have some knowledge about this. I've been reading a lot of things about powder coating magnesium.

    I want to powder coat the lowers of my Dart 3 to match my bke frame (being coated at the same time). Does raising the metal to such a high temperature cause any structural problems. Is this a good idea or should I just paint it with spray paint. I don't want it to snap while I'm riding.

  2. #2
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    Don't know the anwsers ,maybe e-mail RS. Wondering why you would want to spend money on a fork that is that old ? I'd spray it with a rattle can and call it good.

  3. #3
    1/2 fast or 1/2 assed?
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    Im still riding my Dart 3. You'll feel like you wasted your time cause its at most a temporary wheel holder. Im hoping I get a nice enough tax return to replace it. FWIW Im at ~250# and have put in the black (stiffest) spring and its not doing what I want. Its been a little sticky as of late and I just want it gone.

    If you do paint it make sure you post some pics.
    I'm a ******bag in real life so I dont have to be one on the interwebz.

  4. #4
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    The guy quoted me 30 bucks to do the lowers so I figure it's worth it just for the time alone. As far as the fork, I agree it's not the best but it does a decent job for the riding I do and my weight , around 190#

  5. #5
    1/2 fast or 1/2 assed?
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    Personally, I dont think powdercoating could do any damage. IIRC the process only gets to ~ 425 degrees. The tempering process should be much higher. Id still put that $30 away toward a new fork, but thats just me. My fork does match the frame so I dont know how you feel.

    Have you tried the suspension sub forum? Maybe do a search there.
    I'm a ******bag in real life so I dont have to be one on the interwebz.

  6. #6
    Uphill? What's that
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    Do not powder coat magnesium.. I powdercoated a bike frame a few years back and wanted to do the lowers of a domain fork. I called the tech department of the supplier I bought the powder off of and they said magnesium is a no go.

  7. #7
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    ok. with all of the ionions I'm leaning towards just hitting it with some primer and spray paint. Any suggestions or special steps I need to take to paint magnesium?

  8. #8
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    I did a rattle-can job on some fork lowers about a year ago and have been really happy with how they've held up.

    Details and photos here if you're interested.
    Contact information: http://about.me/marpilli

  9. #9
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    Quote Originally Posted by marpilli View Post
    I did a rattle-can job on some fork lowers about a year ago and have been really happy with how they've held up.

    Details and photos here if you're interested.
    it appears your fork lowers are gray like mine. It looks like mine are not epainted at all but rather bare magnesium which could pose a problem. Before you scuffed them up were your lowers glossy smooth? Mine feel like a raw cast past.

  10. #10
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    Quote Originally Posted by bryan.gurc View Post
    it appears your fork lowers are gray like mine. It looks like mine are not epainted at all but rather bare magnesium which could pose a problem. Before you scuffed them up were your lowers glossy smooth? Mine feel like a raw cast past.
    I'm certainly not an expert on fork lowers; but, I'd be really surprised if your lowers were bare from the factory. If you haven't stripped the paint off of them then they're probably painted.

    This fork was painted with a gloss paint (albeit old and not "new" condition) before I scuffed them with steel wool.

    Can you post up a couple of photos of the fork in question?
    Contact information: http://about.me/marpilli

  11. #11
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    Also, if it really is bare, the Rustoleum appliance enamel might be the way to go.

    Quote Originally Posted by marpilli View Post
    I emailed Rustoleum earlier in the week asking about proper application of their appliance epoxy. They specifically said no primer with this paint. Scuff existing paint or apply directly to bare metal. Made me happy to hear that as it saved some steps.
    Contact information: http://about.me/marpilli

  12. #12
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    Quote Originally Posted by marpilli View Post
    I'm certainly not an expert on fork lowers; but, I'd be really surprised if your lowers were bare from the factory. If you haven't stripped the paint off of them then they're probably painted.

    This fork was painted with a gloss paint (albeit old and not "new" condition) before I scuffed them with steel wool.

    Can you post up a couple of photos of the fork in question?
    Here are some pictures. it's a 2008 Dart 3. Cruising the the archives at the specialized website (came off of a rockhopper), they list it as being magnesium. It has to have some sort of coating on it I would guess because I took some sand paper to it and some dust from whatever is on the outside was produced.
    Attached Thumbnails Attached Thumbnails Powder coating RS dart 3 Magnesium Lowers-img_0015.jpg  

    Powder coating RS dart 3 Magnesium Lowers-img_0014.jpg  


  13. #13
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    That color looks really close to the same color as my RockShox SID before painting. If it were me, I'd remove the stickers, scuff it, wash it (really well) with TSP, and paint that thing!

    Whatever you decide, please post up the outcome.
    Contact information: http://about.me/marpilli

  14. #14
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    FWIW,
    you can PC anything that won't melt in an oven, and holds an electrostatic charge.
    There are low-heat powders that can bond to carbon fiber, and I have a set of road bike forks to prove it, lol,

    Also, if you don't paint/coat over magnesium, it will air oxidize very badly over time, so most any manufacturer, wouldn't ever sell a cast magnesium part without coating it with something.

    So, if you strip the paint off your fork, coat it with something.

  15. #15
    Big Gulps, Alright!
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    Discusses PCing various materials: Powder Coating Tech Thread - Q&A

  16. #16
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    tagged for future ref.
    roccowt.
    rocnbikemeld

  17. #17
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    Just a little update. I've decided to strip the grey coating/paint off and rattle can the fork lowers. I was talking with my LBS and he informed me that there are seals/bushings in the fork that require a somewhat specialized tool to remove. This would require sending the fork into SRAM. None of the bike stores I've called in the area have this tool.

    If I were to put the lowers in a curing oven after coating without removing them there is a good chance they would melt/be damaged. so thats a no go.

    On the plus side. I got a used reba for a couple hundo that's supposed to be here today so the dart is good to sit there until I get around to painting it.

    Next question, chemical strippers, a good idea or not? Sanding the entire form would be a pain in the ass, especially with all of the small crevices. Can anyone suggest a good chemical stripper that is available at like home depot or something that would get the job done?

  18. #18
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    Quote Originally Posted by bryan.gurc View Post
    Just a little update. I've decided to strip the grey coating/paint off and rattle can the fork lowers. I was talking with my LBS and he informed me that there are seals/bushings in the fork that require a somewhat specialized tool to remove. This would require sending the fork into SRAM. None of the bike stores I've called in the area have this tool.

    If I were to put the lowers in a curing oven after coating without removing them there is a good chance they would melt/be damaged. so thats a no go.

    On the plus side. I got a used reba for a couple hundo that's supposed to be here today so the dart is good to sit there until I get around to painting it.

    Next question, chemical strippers, a good idea or not? Sanding the entire form would be a pain in the ass, especially with all of the small crevices. Can anyone suggest a good chemical stripper that is available at like home depot or something that would get the job done?
    I would take it to the shop tha was going to powder-coat it and have them media blast it for you.

  19. #19
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    Quote Originally Posted by bryan.gurc View Post
    Just a little update. I've decided to strip the grey coating/paint off and rattle can the fork lowers. I was talking with my LBS and he informed me that there are seals/bushings in the fork that require a somewhat specialized tool to remove. This would require sending the fork into SRAM. None of the bike stores I've called in the area have this tool.

    If I were to put the lowers in a curing oven after coating without removing them there is a good chance they would melt/be damaged. so thats a no go.

    On the plus side. I got a used reba for a couple hundo that's supposed to be here today so the dart is good to sit there until I get around to painting it.

    Next question, chemical strippers, a good idea or not? Sanding the entire form would be a pain in the ass, especially with all of the small crevices. Can anyone suggest a good chemical stripper that is available at like home depot or something that would get the job done?
    If you're going to paint them, I would not recommend removing all of the existing paint. It will be time consuming and is not necessary in most cases. Just use steel wool and a brass brush to rub down all exposed areas. Wash and let dry. Apply paint.

    I've used paint stripper on a hard-tail frame and that stuff is caustic. If you use it on the lowers, keep it away from the wipers. Since it liquifies paint I'd be willing to bet it would liquify the plastic wipers.

    I totally agree you do not want to put an assembled fork into any type of oven. However, it isn't too tough to disassemble the RS forks all the way down to the bare lowers (if you really want to go the powder coating route).

    If you decide to make the Dart a learning experience, I have a thread on bushing removal/replacement here that might be helpful to you. You should be able to find RS service manual and it will give-you-step by step procedures to remove the uppers and seals.
    Contact information: http://about.me/marpilli

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