How do I paint EPP foam???

roguepink · Post by **roguepink** » Mon Apr 25, 2005 7:29 am

I've been using a lot of EPP (expanded poly-propylene styrofoam) for product, particularly airplanes, and I have had a helluva time getting paint to stick agressively to it.

We had a sample of paint from China that works great, but is not domestically available.

I tried to prime with Krylon Fusion flat white. Okay results, but still lifting when I use Tamiya yellow masking tape. That's after cleaning and lightly sanding the surface.

We tried a glossy Fusion (red) and it worked much better. Perhaps the glossy colors stick better?

No other type of primer or paint has had any success in adhering to the EPP surface.

SUGGESTIONS, PLEASE!!!

Scott Hasty · Post by **Scott Hasty** » Mon Apr 25, 2005 12:17 pm

Well, we can do this together! I'm sculpting a 1/6 scale Eastern Island head from the stuff for a client. I just picked up Krylon's H2O. It's a latex paint in a spraycan. Looks a bit different from the typical housepaint.

Scottie

d_coombes · Post by **d_coombes** » Mon Apr 25, 2005 12:24 pm

Dont the rc guys cover the foam with parcel tape?
http://www.jkaerotech.com/t52instr.htm#Wing%20covering
Looks ok from a distance!
Dave

roguepink · Post by **roguepink** » Mon Apr 25, 2005 3:38 pm

No good. The EPP is the final surface. Need paint that sticks to it directly.

Scott Hasty · Post by **Scott Hasty** » Mon Apr 25, 2005 4:36 pm

If the latex doesn't work, try a 50/50 mix of liquid latex (not Mold Builder) and acrylic paint. This is what I use for stubborn surfaces. If that doesn't do the trick, then I'd get checked out after using that Chinese paint....

Scottie

roguepink · Post by **roguepink** » Mon Apr 25, 2005 10:04 pm

Latex, no good. Will not create an agressive bond with the EPP.

I took a sample of the stuff to a local paint store. They soaked the foam in the hottest laquer thinner they had. They were sure it would melt the foam.

Nope.

When I use the stuff from China, I use a NIOSH paint mask. The problem I have with it is non-domestic availability. China can send us some in sample portions, but never enough to build up a real stock. They said recently that they really can't send any more without import issues.

So now I need something domestic, OSHA friendly, and agressive.

I would like to try automotive laquer primer, but auto body places in Colorado are using acryllics now. Some sort of environmental thing. Well SCREW John Denver, okay? He's dead. Give me some really nasty stuff that will cause mass deforestation, because Penose, Colorado ain't got nothing but scrub and cactus growing anyway.

Scott Hasty · Post by **Scott Hasty** » Tue Apr 26, 2005 5:33 am

This may break your "final finish" rule, but I ahve a friend that painted a wing by first spraying a light coat of Super 77 adhesive, then, I believe enamel. Kinda orange peel-like, but it worked.

Scottie

roguepink · Post by **roguepink** » Tue Apr 26, 2005 7:12 am

The final finish rule is not MY rule. Estes-Cox is using EPP foam for all their new airplane wings and fuselage parts. The finish must be smooth and clean. Also, to maintain low flight weight, a minimal layer of paint must be used. Too much surface texture will cause friction, reducing wing performance.

You see what I'm up against?

Scott Hasty · Post by **Scott Hasty** » Tue Apr 26, 2005 8:13 am

roguepink wrote:Estes-Cox is using EPP foam for all their new airplane wings and fuselage parts.

.

Smart move, using EPP. It's very durable.

roguepink wrote:You see what I'm up against?

Don't you love it, the challenges? Don't know where to go from here. Perhaps some sort of ink. I guess pre-coloring the part and detailing with [peel-and-stick] decals is out; actually I would think that would keep costs lower because you would, in effect, skip a step [painting].

BTW, what's the deal with the Estes hydrogen rocklet line? Seems a dangerous.

Scottie

Mr. Badwrench · Post by **Mr. Badwrench** » Wed Apr 27, 2005 4:29 am

Maybe some sort of stain would work.