White paint directly on EPS foam

On my next build I’m planning on doing a resin tint cutlap on bottom, and clear lam on top. I was thinking of lightly painting the top a water base white paint directly on the foam thinking that this will make the board stay bright white in the long run as opposed to the foam yellowing over time in the sun and from use. Has anyone tried this? Will it work in keeping the board white or is it a waste of time?

I was thinking of tinting the resin white for the top but I also want the stringer to show.

I’ve noticed not the foam but the resin yellowing.
I’ve done white water based spray paint on the foam directly, as my filler was off white, it works, but i think the resin to be UV is more important and also dont leave it on the sun.

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@Mitch_W fyi, just moved this to general discussion vs. build threads.

What Aleksander said. It’s the resin that yellows… if you are using EPS. Polyurethane foam will yellow. Think of styrofoam trash. The bits are still white. If you’re using epoxy you could try “2100 ultra plus optical brightener.” The resin looks blueish. It will also slightly change the color of the bottom adding a purplish tint.

EPS will yellow over time, I have some that has sat around for years with a little UV exposure and it has “tanned” over time. As mentioned though, some resins will yellow as well, particularly the non surfboard specific formulas.

WEST Systems epoxy, in my experience, mainly used for boat building and meant to be under paint, will turn brown in fairly short order… I don’t know if they have a UV resistant blend. I haven’t used their stuff in over 20 years.