Here is the skinny. Resin Research epoxy on EPS. Hotcoated and sanded. I first sprayed Krylon for plastics, everything looked fine. I then sprayed automotive clearcoat over the Krylon and the paint starts cracking and lifting all over the board! I figured it was a bad reaction between the paint and clear caot, so I sand it out, switch to rustoleum for plastic, and rustoleum clear (same brand ought to be compatable right?) This crap cracked too! What the heck am I doing wrong? The shop is in the mid 60’s to low 70’s, I have been very careful not to touch the board with bare hands. I have sanded and repainted this thing several times now, and I am getting pissed! Any ideas?
I’ve done alot of painting in my life. I have never used the paints you are using. If your RR and EPS are fully cured they are not part of the problem. I see two things. Heavy coats without enough dry time between coats. Or Base coat is not compatible with top coat. Most likely both…It’s been a long time since I’ve sprayed a car…fog coat first, then light coat, then another light coat, then lay it on good…slow down
I will try both of those suggestions, thanks guys! I do tend to spray too heavy. I will try harder on that.
I know a lot of you guys like concrete sealer, how durrable is it compared to a 2 pac clear coat? I know it is far cheaper, but am worried about its lifespan. I’m not into making disposable boards.
I paint every day. Stingray is right on. That is classic top-coat attacking the base-coat. Check the technical data sheets to make sure they are compatible. (You should be able to get the tech data sheets online with a google search.) It may well be a matter of letting the base coat dry more and applying the clear in thinner passes. Bear in mind some rattle-can clears tend to dry more slowly to ensure they stay glossy. The heavier you apply it the wetter it stays. More time wet = more time for it to attack the base-coat.
In answer to your other question, 2-pac clear will be harder, more UV resistant, and more solvent resistant than a wiped-on acrylic (assuming it’s applied correctly). 2-pac is also more likely to flake and peel eventually when subjected to the realities of life as a surfboard. But really, I’d be more concerned about the moral implications of painting the board in the first place. I mean, think about the poor thing’s soul. Not judging. Just sayin.
I would leave it white if it was for me, but the customer wants purple. Thanks all for the help everybody! I am not going for gloss, as much as keeping the paint from getting dinged up too bad. I will try the Behr on this one.
Read the instructions on the label and test on a sample panel before doing the whole board. Instructions on recoating (even with same brand) can change from year to year as EPA regulations kick in. Can’t really go wrong with a test on a sample panel. Most rattle can paints will be inferior to real 2-part (catalyzed) stuff from a compressor/spray gun. There are some that are in fact 2-part in a rattle can. Pay particular attention to MSDS and label warnings with any of this… the stuff can kill ya.
Those paints for plastic are made for softer plastics. They have extra adhesion and elasticity for those particular plastics. Just use the plain old rattlecan stuff and the appropriate primer. Don’t over-think it.
Its got nothing to do with the epoxy…or the paint…or brand of paint etc.
What you did wrong is that you didn’t let the paint dry long enough. You need to let the paint set up, then you can spray the clear coat. Next time let it dry and set up for 3-5 days, then hit it with the clear coat. If you don’t wait long enough all the goodies in the clear coat will act like acetone…or a thinner and melt, craze and peel through the paint. Trust me on this…I see it all the time…next time don’t rush, let it dry a lot longer than what it says on the back of the can
You will get the samething sometimes putting asecond coat of paint over it…just making it worse.
I have never hada problem useing acrylic paints over epoxy. I Have also used some mono epoxy marine finishes on SUPs with excellent results. Do as Maco said and use some of the wipe on Behr as top coat to give the paint some extra protection.
