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  1. #1
    Senior Member bleedingapple's Avatar
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    Powder Coating Aluminum

    Ok so some of this post might seem silly but I really need some clarification. So I'm looking to get a new aluminum frame, I hate the color and want it repainted... Now my question is, am I going to compromise the strength of the aluminum by it going into the oven for the powder coat?

    I also overheard someone speak on the matter of just painting it with a rattle can (a nice one like dupli color or the like) and it actually adding strength to the frame as its another layer aka wall thickness. I was wondering how true this was?

    thank you very much for any info you can offer

  2. #2
    Senior Member PaPa's Avatar
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    Not a problem as long as the facility doing the coating knows, and adheres to cook times and oven temperatures. The following is a scan from:

    ASM Metals Handbook
    8th Edition Vol. 2
    Heat Treating, Cleaning and Finishing
    Page 277

    Last edited by PaPa; 04-09-10 at 01:46 AM.

  3. #3
    Senior Member ftwelder's Avatar
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    adding paint will not increase strength. The old paint must be completely removed with acid (paint stripper) before painting. If you send it to someone who is not familiar with aluminum bicycle frames it will most likely be destroyed. The above scan is completely unrelated to your situation.

  4. #4
    Senior Member PaPa's Avatar
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    Quote Originally Posted by ftwelder View Post
    The above scan is completely unrelated to your situation.
    Please clarify.

  5. #5
    Senior Member ftwelder's Avatar
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    Quote Originally Posted by PaPa View Post
    Please clarify.
    those figures are for changing the condition of the material. The mass of the part, material, type of oven, cold or hot flocking, brand and type of powder are the factors that determine cure time for coatings. There are many things a painter can do that will destroy your frame. If your painter needs to be told cure times the chances of success are pretty minimal from the git-go.

  6. #6
    Senior Member PaPa's Avatar
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    My initial response and the supplied 'scan', was specifically aimed to address the OP's concern regarding compromising the "strength" of his frame during the PC process... and NOTHING more:
    Quote Originally Posted by bleedingapple
    "Now my question is, am I going to compromise the strength of the aluminum by it going into the oven for the powder coat?
    Re: your comments,...
    Quote Originally Posted by ftwelder View Post
    The above scan is completely unrelated to your situation.
    I disagree.

    Quote Originally Posted by ftwelder View Post
    those figures are for changing the condition of the material.
    Apparently, you don't have access to the book referenced (or more specifically, the chapter) the scan was pulled from. Clearly, the scan can be referenced for nearly any purpose which gives concern when the alloy is "reheated", as the chapter the scan was pulled from clearly states, quoting from page 277:

    "Effects of Reheating

    The precipitating characteristics of aluminum alloys must frequently be considered when evaluating the effects of reheating on mechanical properties and corrosion resistance. Such evaluations are necessary when determining standard practices for manufacturing operations, such as hot forming and straigtening, adhesive bonding, and paint and dry film lubricant curing, and when evaluating the effects of both short-term and long-term exposure to elevated temperatures in service."


    ftwelder,
    Although rather expensive, I would highly recommend that you purchase a copy prior to making inaccurate judgments about its content suitability.
    Last edited by PaPa; 04-27-10 at 02:35 PM.

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