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epoxy over regular primer

Discussion in 'The Hokey Ass Message Board' started by oldspert, Oct 22, 2013.

  1. oldspert
    Joined: Sep 10, 2006
    Posts: 1,258

    from Texas

    I have some of the body parts to my 46 primed with some red plain primer. Can I shoot epoxy primer over this or do I need to sand it off before the epoxy?

  2. chopolds
    Joined: Oct 22, 2001
    Posts: 5,868

    from howell, nj
    1. Kustom Painters

    Sand it all off!
    1. You don't know if it was applied correctly, might not be adhered well, and flake off
    2. You don't know what's under it....poorly done filler, rust, primer is porous and absorbs moisture, so even if it looks good, might be rust lurking under it.
    3. Do you know what type of primer it is? Lacquer, acrylic enamel, alkyd? Epoxy might not like going over it!
    4. Nothing better for corrosion resistance, water resistance, and adhesion, than epoxy primer, why would you want anything else sitting on your bare metal?
    5. Paint is so expensive now a days, why would you want anything inferior under it?
  3. Bugguts
    Joined: Aug 13, 2011
    Posts: 691


    Yep, what CHOPOLDS said.
  4. robertsregal
    Joined: Oct 2, 2008
    Posts: 743


    Agreed, remove primer for all the stated reasons!

  5. Catdaddyo
    Joined: Mar 9, 2005
    Posts: 136


    Well said Chopolds

    Posted using the Full Custom H.A.M.B. App!
  6. 40StudeDude
    Joined: Sep 19, 2002
    Posts: 9,441


    A chain is only as strong as its weakest link...

    Joined: Dec 27, 2009
    Posts: 1,236


    Epoxy should always be over BARE Metal.

  8. oldspert
    Joined: Sep 10, 2006
    Posts: 1,258

    from Texas

    1. I applied it and it was correct.
    2. Applied over bare metal that was treated with OSPHO.
    3. Acrylic enamel primer.
    4. I shot this because I did not have time to mix epoxy primer and did not want flash rust.
    5. That is why I'm trying to find out if I need to remove it.

    How many of you guys are professional painters.
  9. chopolds
    Joined: Oct 22, 2001
    Posts: 5,868

    from howell, nj
    1. Kustom Painters

    Ahhhh you didn't say you did it yourself!
    So, if you know what it is, that makes it easier.
    Personally, I do epoxy (HOK EP-2) almost exclusively. No harder to mix or spray than any other primer, just a bit more clean up, as it is so sticky!
    If your acrylic is over a year old, and you used a hardner in it, it "might" be OK to go over it with epoxy as a sealer. You have a pretty good chance for success.
    I tend to be very cautious, though, and I would remove most of it just to remove ANY chance of paint failure. Even when you do things 100% correct, there are still times it fails. So removing even the smallest chance it will not work is good insurance for saving time and money. For example, I'm painting a 73 Riviera for a good friend. Going over a mix of original lacquer plus some panel repaints over the years (paint unknown). Got to go to bare for me to be at ease....the Pearl White paint I just bought cost about 1400$. Don't want to eat it if there is a problem!
    But a little time with a DA and some 80 grit will remove that old primer. I wouldn't worry about removing every spec of it, though, as I would with an unknown.
    Good luck!
  10. snopeks garage
    Joined: May 25, 2011
    Posts: 555

    snopeks garage
    from macomb MI

    I retract that statement. I allways use etch and 2k urathane primer
    Last edited: Oct 24, 2013
  11. ABONES
    Joined: Dec 3, 2004
    Posts: 994


  12. NMCarNut
    Joined: Nov 28, 2009
    Posts: 630


    With what you said and assuming you did apply it correctly, the answer depends on the amount of moisture over time the car was exposed after priming. And that includes humidity. Take into consideration regular primer is not a moisture barrier and while it will slow it will not stop moisture from reaching the metal below. And if the moisture does reach the metal the regular primer will also hold the moisture releasing slower than if the metal were bare. So you really have to be the judge. If it has been inside the whole time in a low humidity atmosphere and never wet you might be OK by just scuffing and applying epoxy.

    But if you brought it to me, without stripping I would make no guarantee no matter how you told me it was stored. And yes, I am a professional painter.
  13. rustang
    Joined: Sep 10, 2009
    Posts: 710


    Most epoxy primers do not like etch primer......I know SPI says never to go over etch...
  14. MP&C
    Joined: Jan 11, 2008
    Posts: 2,341


    ......and neither SPI or House of Kolor likes Ospho..
  15. banditomerc
    Joined: Dec 18, 2005
    Posts: 2,265


    go for it,sand it first so it bites..
  16. These threads crack me up......

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