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Paint bubbling

Discussion in 'The Hokey Ass Message Board' started by jake_t327, Oct 7, 2013.

  1. jake_t327
    Joined: May 24, 2011
    Posts: 9

    from Custer, MI

    I just painted my wife's '55 using restoration shop single stage Acrylic Enamel Hot Rod Satin Black. I've never ran into this problem, but I'm getting tiny bubbles forming as soon as I spray it on. I'm using a Devilbiss Starting line with a 1.3 tip, also tried a 1.8 tip. I've tried to adjust air pressure, change tips, and I know my gun isn't the best in the world, but the epoxy primer went down really nice, and I've never had this problem. Anyone got any ideas what could be causing this???
  2. Pete Eastwood
    Joined: Jul 27, 2011
    Posts: 990

    Pete Eastwood
    from california

    Sounds like the problem I had. My painter buddy told me thats from going back to soon between coats. He told me to watch the clock, let it sit 20 min. between coats. After I followed his advice no more tiny bubblels !
    What happens is the first coat hasn't gassed off yet, and the next coat covers it, then it gasses through that next coat causing lots of tiny bubbles.
    Joined: Dec 27, 2009
    Posts: 1,236


    Could also be contaminated air supply (ie. water or grease in the air) ? ? ?

  4. henryj1951
    Joined: Sep 23, 2012
    Posts: 2,304

    from USA

    stick-e but NOT string-e to the touch


  5. I had same issue, was told it was because I used a reducer/thinner that wasnt correct and it was flashing off faster than normal and causing that
  6. What type of filter are you using for the supply air to the gun? Are you using a water seperator?
  7. afaulk
    Joined: Jul 20, 2011
    Posts: 1,191


    You may need to adjust the volume of paint (down) sounds like it may be way too wet. Turn the adjustment down about half way and try a test panel. Turn it down more if necessary.
  8. Did you prep it before spraying? HRP
  9. mikhett
    Joined: Jan 22, 2005
    Posts: 1,412

    from jackson nj

    sounds like moisture in the air lines.I run a Sharp F88 moisture filter ive never had a problem.
  10. VoodooTwin
    Joined: Jul 13, 2011
    Posts: 3,455

    from Noo Yawk

    Sounds like "solvent pop". Can you post a pic of the problem areas for a better diagnosis?
  11. Noland
    Joined: Oct 16, 2007
    Posts: 1,237


    Yea sounds like solvent pops. Happens when you put on too many coats too fast.
  12. I agree it sounds like solvent pop. Some things to consider

    Make sure your using recommended thinner/reducer based on temperature, humidity, air movement and size of repair.
    Allow for proper flash time between coats.
    Avoid "piling on" or double wet coats.
    Restrict air movement over the surface being painted.
    Avoid extended purge/flash time before force drying.
  13. If its the first coat, I gather from the as soon as I spray it on part, its got to be some type of contamination. Could be anything from silicone particulates in the air, on your clothes or equipment like tire dressing, Trans fluid, armor all, or out of the gun all the way back to the compressor or something on the car. Clues are the location and is it everywhere or patches.

    If its in the following coats it's probably solvent pop and not following the tech sheet for ratios, flash time between coats, temperature, or proper reducers.
  14. jake_t327
    Joined: May 24, 2011
    Posts: 9

    from Custer, MI

    I'm using a water separator and also an inline air filter right on my gun. I've got the air set at 15 lbs., and I let the epoxy primer flash over for 60 minutes, like it said on the can. However, i wiped it down with acetone before I put the topcoat on. Could the acetone be gassing off?? Thanks
  15. herbet99
    Joined: Jan 16, 2009
    Posts: 194

    from Central NJ

    I'd be reluctant to use acetone on a freshly painted surface

    Posted using the Full Custom H.A.M.B. App!
  16. rustang
    Joined: Sep 10, 2009
    Posts: 710


    Solvent popping.... +1

    We see this from time to time in an industrial setting...... make sure you follow flash times, and your products are compatible...your undercoats are gassing off....

    Could be that acetone let the epoxy gas off more, then when you topcoated, you got the popping.....

    Why did you put acetone on it?
  17. Leviman
    Joined: Dec 11, 2012
    Posts: 201


    Acetone is one of the solvents in enamel, isn't it? That probably could cause some problems.
  18. paintworks_unlimited
    Joined: Mar 17, 2008
    Posts: 78

    from Dover, NH

    I'd put money on the acetone. It does not evaporate quickly. It most likely soaked in and is gassing through your topcoat. If you can, try peeling the paint off in an inconspicuous area like a window or trunk jamb. Often you can peel the paint right off when this happens. Sucks.

  19. Where in the world did you get the acetone on fresh epoxy idea from ?
    Its Nail polish remover you know or an alkyd enamel ( oil based) reducer- Certainly not on the tech sheets.
    And acetone isn't a suitable prep solvent anyway.
  20. MP&C
    Joined: Jan 11, 2008
    Posts: 2,348


    Solvent pop isn't going to occur until after the first coat has flashed, sealing in solvents. Something happening as soon as you spray it is contamination, either in air supply or on the panel. As an FYI, once the epoxy (or whatever coat for that matter) has flashed and is ready for recoat, I never screw with the previous coat unless something wrong has occurred. ie: dust nib to remove, fish eye in paint, etc. Otherwise there should be no reason whatsoever to re-wipe a panel.

    At this point you are ready to spray the next coat, not wipe and risk introducing contaminants.
  21. 40FORDPU
    Joined: Mar 15, 2009
    Posts: 3,009

    from Yelm, Wa
    1. Northwest HAMBers

  22. jake_t327
    Joined: May 24, 2011
    Posts: 9

    from Custer, MI

    It was my wife's idea, she was super paranoid that some dust settled on it, so she wiped it down, and I didn't even think about it. Definitely learned a lot of what not to do now.
  23. TR Waters
    Joined: Nov 18, 2006
    Posts: 1,439

    TR Waters
    from Vermont
    1. Early Hemi Tech

    Try a tack rag next time.
  24. jazz1
    Joined: Apr 30, 2011
    Posts: 1,496


    Definitely a contaminent and acetone is a likely culprit. I only use R-M 900 for cleaning a vehicle for paint. It dissipates quickly from the surface. I have used Restoration Shop Acrylic single stage to paint my sons truck and I thought it was the best bang for your buck. Very durable, easy to spray and great shine.
  25. jake_t327
    Joined: May 24, 2011
    Posts: 9

    from Custer, MI

    Yeah, I got a bunch of tack cloths now,, definitely feel ultra stupid after this one.
  26. overspray
    Joined: Jan 14, 2003
    Posts: 1,232


    To the digicam, and post some pics.

    I see you have close to 90% humidity and it's cool (64-68 F) in your locale, which will slow the solvents coming out.

    The acetone was not a good idea. It may have opened the epoxy coat and caused some type of reaction.

    Is your main water separator at least 20 feet from the compressor? The high humidity is going to produce a lot of moisture in the compressor and lines. You need to have the water trap/separator away from the compressor so the air can cool and condense the moisture. The heat of the compressor keeps the moisture evaporated in the airflow.

    Did your wife have a fresh application of perfume or other smell-good on when she wiped it down? A lot of perfumes have silicone in them, which is a cause of fisheyes.

    Another possibility is old hardner for the acrylic enamel. It will "kick" fast and produce small pimples. This is called "seedy".

    Flattened paint will dry much faster than non-flattened. You may need to go with a slower reducer because of the flattener.

    Or "D" all or any combination of my post and all the others.

    At least you have some good feedback from the painting crowd.

  27. jake_t327
    Joined: May 24, 2011
    Posts: 9

    from Custer, MI

    I definitely appreciate the feedback, the water separator was only a couple feet from the compressor, so I'll change that also. No perfumes were used in the painting of this car. Thanks again
  28. jazz1
    Joined: Apr 30, 2011
    Posts: 1,496


    "OVERSPRAY" makes an important point regarding how fast flattened paint will dry. I had a bitch of a time spraying Flatz Paint..dry spray was the biggest problem and later on it was suggested and made sense that i should have switched to a slow reducer.

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