Hi all, I know that for painting the foam before grlassing we need to use water based (latex) paints, but I'm wondering if all paints are created equal. The reason I ask is that I just realized that my kids have a bunch of plastic bottles of thick non-toxic paints that could be thinned a bit (from their younger days doing "crafts"). We have lots of different colours, but I wonder if these might fade fast or if there is any good reason to not use our collection of dollar-store kiddie paints? I was thinking I might thin them and spray them.
Most of the kids paints I have kicking around here dry to a powdery finish that oftentimes has a weak bond (by design to help you clean their clothes,floor, furniture, face, walls, carpet, windows, teeth....you get the idea) As a result, it has high potential to create a layer between the epoxy and the foam weakening or possibly preventing a sufficient bond.
As with all things composites I would recommend running a test panel using scrap pieces of the materials you intend to use. As I found out with various mold releases, compatibility issues are very dependent on the exact resin and paint you intend to use. Read through Swaylocks and there are tons of different success and failure stories "shellacing" the core resulting or not resulting in de-lamination. Blows my mind guys are using latex paint...and it works(ish?). Again wouldn't consider this unless I ran a test panel
If the foam rips apart before the laminate comes off you're good enough.
Yes, I can do a test for the bond, but I was also wondering about other issues like how the colours last. Do the UV inhibitors in the resin protect what's below the resin, or, more likely, do they just help the resin withstand the efects of UV?
As for the paint turning dry and dusty, that might be a good thing. If the resin then soaks into it, and through to the foam, you don't have to rely on the bond of the paint to the foam and the paint to the resin. I would think a thin dusty dry paint coverage would be the best for a good bond, as if the paint is not really there at all. Not sure if I will be testing enough different paints and applications to fully investigate that..... but I'll at least make sure what I do works structurally.
Sounds like your doing a surfboard? I have done some really crappy paint schemes in my time, even using fancy pro grade paint. You have to really be gifted, and/or know what your doing. It's hard to do a really good spray. Are you inspired? Or just want to find a use for that paint that's been laying around?
A clear (white) board always looks great. You can shoot a rattle can over it if you really want some color. And sand it off if you don't like it.
Actually, I'm doing a twin tip. I've painted a few boards, twin tips and directionals in the past, but this is the first time I'm painting corecell under the glass. "Bigdog" on this forum has done it lots of times with success. My rule of thunb is to have a white base, and a few basic shapes or stripes masked, with some bright colours and some fades within the masked area. Usually looks half decent.
As far as the test goes, I painted some foam (using a sprayer and the kids paints), and glassed over it. To rip the glass off, the lightly painted foam might have pulled off a touch easier than the clean foam, but the difference was minor. In one spot I accidentally really pooled the paint, but left it to fully dry. The glass did pull off easier there, so that is clearly something to avoid. Not exactly discovering anything new and unexpected there though.