Learn to Powder Coat

Discussion in 'The Garage' started by mudvaynedude122, Aug 27, 2013.

  1. mudvaynedude122

    mudvaynedude122 Adventurer

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    I started powder coating at home a couple of years ago for a car restoration and I started working on a powder coating site that I could put everything I have learned to help other guys out. All of the articles I have written are 100% aimed at guys in their garage but still using the same practices that a pro would use. I am not claiming to be a pro or anything (I dont think pros make how-to sites??) but I am several years ahead of the new guys and I am not the type to cut corners and do things half-assed.

    Anyways, if you guys want to check it out, heres the welcome page: http://www.powdercoatguide.com/2012/11/welcome-to-powder-coating-complete-guide.html#.Uh0Ww-WWnrQ

    Feel free to ask me any questions you may have about powder coating.
    #1
  2. Chilipepper

    Chilipepper Baja wannabe

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    Took a look at your site. Someday I'm going to try this and your info will be great.
    #2
  3. mudvaynedude122

    mudvaynedude122 Adventurer

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    Good to hear, thanks man
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  4. H96669

    H96669 A proud pragmatist.

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    Very good...I just went and checked for stripper. We are having a hard time with some of the BMW stuff but still aren't sure if it is Powdercoat or like some claim a 2 part Urethane. In any case it is hard to remove.:cry

    But my friend that has the setup thinks it is powdercoat and that we then could just media blast and maybe sand the coating and refresh it with fresh coats of powder. That could save us so much work.:ear

    Any experience with Magnesium? Some of my BMW covers are bubbling and I think they are outgassing even after a few years and that's causing that, that is "if" as we think they are powdercoated.:ear
    #4
  5. dennism

    dennism dennism

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    I'm restoring an Africa Twin.

    It has a large aluminum bash plate under the front of the engine and frame, in three pieces..

    I carefully repaired all the dings and pits and polished the parts by hand using several grades of Scotchbrite. Then I took it for powder coating with clear, hoping to keep the polished look, but give the plate some protection from tarnishing due to road chemicals, aggressive bug guts, whatever. The coater has done excellent work for me on other things.

    The shop tried to coat it but couldn't get their clear to coat properly, and they said it was out-gassing, and looked terrible. It did.

    I didn't want them to sandblast it of course, because then I would lose the polished look that I had spent so much time to achieve.

    Finally, I gave up and had them sandblast and put on a bright silver coat, which is not what I wanted at all, it looks like a light gray paint.

    I'd happily take the coating all off and do it again, but ....

    How to best remove the coating?

    How to prepare the new surface?

    Can I get the finish I want?

    I'll appreciate your advice. :ear
    #5
  6. mudvaynedude122

    mudvaynedude122 Adventurer

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    I have heard of some bmw wheels as well as some other oem wheels having difficult coatings to strip. It will come off in Benco B17 stripper. It normally strips powder off in less than 20 minutes but some of the difficult finishes can take several hours in the stripper. Media blasting powder coating will take all day unless you have a serious compressor and blasting setup. I have done it with a 12cfm compressor before with 4 wheels and it took me a good 12 hours.

    It sounds like you are have a powder coating business from the way you wrote your questions, if you are, then definitely look into the b17, it will save you a lot of time but you must be careful with it.

    Since you are not sure of what is currently on the wheels, I do not recommend sanding and powder coating on top, the only time I would ever powder over anything but bare metal is if I just powder coated it myself.

    I don't have any experience with 100% magnesium parts, just parts that are a magnesium alloy. If they are outgassing on you after you coat, are you doing a pre-bake cycle before you coat. You want to do it at a higher temperature and longer than your cure schedule. I usually do 430 degrees F. The time depends on how long the part smokes in the oven. Still this step does not 100% prevent the outgassing from occurring. If you suspect a part will outgas on you, it is best to spray the part with Red Oxide primer. It is meant to be hot-flocked(you heat up the part in the oven, pull it out and coat it immediately. At 460 degrees, it cures in 1 minute. Because the powder is cured basically as you spray it on, it seals the part up and traps any contaminates from outgassing. Once it cools, you can then topcoat.
    #6
  7. Sheep Shagger

    Sheep Shagger Show me your fleece

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    Really like the information and site. Good job.
    Topic for you to consider is something that's key with all my garage friends is curing powder on items larger than the oven you have.
    #7
  8. mudvaynedude122

    mudvaynedude122 Adventurer

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    That sucks that the part was already blasted, as re-polishing it will probably take longer the next time around. What you want is possible as far as I am concerned.

    The skid plates are not cast aluminum are they? From the pictures I saw, they just looked like stamped sheet aluminum. I have never heard of non-cast aluminum outgassing. I am thinking there was a lack of prep somewhere, oils on the parts or maybe polishing compound(did you use polishing compound?)

    These are the steps I would take:
    -Chemically Strip the powder coating off, call a couple shops in your for stripping quotes.

    -Re-sand down the parts to they are smooth again, you will have to use something more aggressive than scotchbrite this time around since they were blasted, at least for the beginning stages.

    -Assuming you are used a polishing compound to polish the parts, you need to get all traces of the compound off. MEK is the only chemical I have used that will for sure get it all off. Thoroughly clean the parts with MEK and several clean rags, constantly flip the rag to a clean area until the rag comes up clean, then wipe once again for good measure.

    -Take the parts to the sink for a water-break test. Run some water over the polished surface, you should see one uninterrupted sheet of water flowing on the part. Anywhere the water splits on the part no reason, there is a something there: compound, oils, dirt, ect. Clean this area again.

    This is usually the time where you can take them to your powder coater, but I will finish the instructions as if you were doing them yourself...

    -After the parts pass the water break test 100%, I would then wipe down with denatured-alcohol, blow off with air and bake in the oven to dry completely.

    - Then spray with the clear powder and bake.

    If the powder coat has any fish-eyes this time around and you want to try again, do not blast it, chemically strip it, it will save you the re-polishing step.
    #8
  9. mudvaynedude122

    mudvaynedude122 Adventurer

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    Thanks. I wish I knew an easy way to cure parts bigger than the oven but unfortunately, I don't have anything new to offer.

    Options:
    -Preganant oven(build an enclosure to add to your oven to make it bigger
    -Build a big oven
    -Combine 2 or more ovens together(I will be doing this)

    I have seen one guy use propane heaters to powder coat his entire car frame. He coated the entire frame and then moved the heater around his frame until the whole thing was cured. This is kind of a do-at-your-own-risk thing though, I am sure doing it this way affects the finishes durability somehow. I will be doing something similar soon to see how it works. I have a propane grill have I have used to cure a few parts. It's lid has a hole on each side for a rotisserie. I have several brake lines that run underneath my car that I need to coat and they are about 12 feet long, bigger than oven I will ever have. I plan on coating one section at a time and feeding it through the holes in the grill lid. I will practice on a bar first, if successful, I will post about it on the site. The only thing is, I have 5 lines that run under the car, each 12 feet long, the color I want do do requires 2 coats and my grill is only 3 feet long. So 5 lines x 4 sections x 2 coats = 40 cure cycles.. Should be a fun weekend :)

    Heres my proposed oven plans, picked up both ovens for free off craigslist:
    [​IMG]

    [​IMG]
    Sorry for the huge pics.
    I will be cutting out the 2 middle walls, and adding sheetmetal on the bottom, top, and back to fill the gaps, using insulation from the walls I cutout. Then I will bolt the doors together so they open as one. Then turn the whole unit on its side to give me a nice tall oven. If it works, it will be a completely free oven that I can fit up to 53" inch long parts in:)
    #9
  10. H96669

    H96669 A proud pragmatist.

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    Not into business, my friend is "sort of" as a sideline to his other work. He doesn't have the patience to dig up the stuff on the net so I do it and then we can experiment. Now that he has learned not to quote too quick on my parts, he sure found out how hard they are to strip.

    I have some other BMW junk parts to experiment with, will see how it goes after we fully read through your site. Powdercoating wood that sure is interesting to me, his oven is big enough for rather large pieces.

    Now to find the b17 in Canada.:cry

    Thanks for putting it all together.:thumb
    #10
  11. mudvaynedude122

    mudvaynedude122 Adventurer

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    Oh, your in Canada.. B17 would probably cost you triple over there. Sorry, I am not familiar with what powder coating strippers are available in Canada.

    Let me know if you have any more questions, the site will still receive regular updates a couple times a week so check back.
    #11
  12. dennism

    dennism dennism

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    "The skid plates are not cast aluminum are they?"

    No, Stamped sheet is all..

    "These are the steps I would take:
    -Chemically Strip -Re-sand - polish the parts -clean the parts with MEK
    -Take the parts to the sink for a water-break test.
    This is usually the time where you can take them to your powder coater, but I will finish the instructions as if you were doing them yourself...

    Wipe down with denatured-alcohol, blow off with air and bake in the oven to dry completely.

    - Then spray with the clear powder and bake."

    Thanks! I'll give it a try. Probably use some chemical paint stripper, as many times as it takes. I have lots of time, so I'll try this first.

    Wish me luck!!! Dennis. :clap
    #12
  13. mudvaynedude122

    mudvaynedude122 Adventurer

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    Hey, sorry for the lately reply. Good luck! and I mean it, lol. I don't envy stripping powder coat with off the shelf strippers at all, be prepared to apply the stripper 15-20 times. Dont get the aerosol because there is just not enough in the can. I would get the can that you can dip stuff in. Then soak some rags in the stripper and lay the rags over your parts. That will keep the stripper on the parts and hopefully stop it from evaporating too fast. This is assuming the parts wont fit inside the can of stripper.
    #13
  14. mudvaynedude122

    mudvaynedude122 Adventurer

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    Anyone else interested in powder coating, feel free to shoot some questions my way.
    #14
  15. mudvaynedude122

    mudvaynedude122 Adventurer

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    Here is some stuff I have been coating lately. Sorry guys, its not for a bike, but a car project I have been working on. Not too interesting since everything is matte black, but my goal for the car is a clean oem like restoration, not so much a real flashy look.


    Transmission shield:
    [​IMG]

    Engine brackets:
    [​IMG]

    Brake dust shields:

    [​IMG]

    Here is some stuff from the past:

    Starter:
    [​IMG]

    Wiper motor cover:
    [​IMG]
    [​IMG]

    Alternator housings:
    [​IMG]

    Some calipers I did for a friend:
    [​IMG]

    Tank:
    [​IMG]

    Brake and clutch master cylinder:
    [​IMG]

    Also have been doing some polishing:
    [​IMG]
    #15
  16. mudvaynedude122

    mudvaynedude122 Adventurer

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    Well this thread is pretty dead, but I finally wrote a new article on the site. It should be a good read for anyone thats thinking of buying an air compressor in the future.

    How to Choose an Air Compressor
    #16
  17. mudvaynedude122

    mudvaynedude122 Adventurer

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    So has anyone here started powder coating recently?
    #17
  18. ktm360mx

    ktm360mx Stone Cold Puppy Pa

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    I haven't started yet, but looking into it currently. We are building a Factor Five 818 and have been painting various parts like above. The look great, then I made the mistake of wiping down the fire wall with some brake cleaner. It was what I had in my hand at the time and started dissolving hte paint.

    Soo, now looking at powder coating again.
    #18
  19. groop

    groop So much to ponder

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    Love this thread and your informative website. The PC'd fuel tank has me thinking about doing the same, but there is a tiny bit of plastic filler that was used. How would this work as a PC candidate? I would assume the polyester filler would not stand up well in 400F ovens as a preheating method.
    #19
  20. H96669

    H96669 A proud pragmatist.

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    There are "all metal" types fillers for powdercoating.

    Bugger some of the parts my friend powdercoated for me last year are rusting again. But if figures....centerstand and rock chips, I was expecting that some.

    So I bought this....Canadian product that will "apparently" prevent steel from rusting ever again:

    http://lloyds.targetnetwork.net/kryptonite-metal-treatment-satin-black-455-ml-16-oz-bottle/

    Test piece I put in seawater did look good after a few weeks. They don't say if it can be powdercoated but it does resist 800F so I'll be doing a powdercoating test on that.
    #20