foam stain and poly filler

I just took an old beat up 8’ and reshaped into a shortboard. Even after re-shaping, there is still a noticeable amount of brown foam. I’d like to do a foam stain to cover up the old foam, and make it look like the new (to me) board that it is. I am going to have to do a skim coat of filler in some places to cover up some gouges from where the foam was still attached the the old glass when I ripped it off.

My question is, if I use poly sanding resin, with white tint and cabosil to fill the gouges, will the tinted lam resin stain the foam and the cured filler the same? If not, will multiple coats of tinted resin help make it more uniform?

Any experience or help on this would be useful. Worst case scenario, I’ll air brush it to get more uniform coverage. I would just rather use a foam stain for better adhesion.

Thanks for the help!

“will the tinted lam resin stain the foam and the cured filler the same?”

No.  If you have any scraps, try it and see.  A big part of color is how it soaks in to the foam.  I believe you’ll find that the patches don’t suck up nearly as much tint as the unfilled foam.

“If not, will multiple coats of tinted resin help make it more uniform?”

To some degree, maybe, but the patches will still be noticeable for the same reason stated above.  Again, try it on scrap to double check.

If you need any scrap foam for tests, PM me and I’ll mail you some.

 

johnmellor, thanks for the input! That is pretty much what I thought would happen. Luckily, I have plenty of scrap foam in the shop to test it on, and will check it out in the next day or so!

I may try to tint the filler with color before the stain to try and get close to uniform color! Time will tell.

Not sure if it works on polyurethane assuming it would though, what about using a spackle to fill in the spots? It’s used on paddle boards for that same reason and can be foam stained.

maybe try using lam resin instead of sanding resin when u make the cob o sil mix.  The tinted lam resin you use for your foam stain might adhere better with the filler that way.  That is just a guess though.  maybe do a foam stain resin swirl with some white pigmented resin in it. then the white patches might just look like part of the swirl if they are still visible.

Spackle will show, lam resin won’t do anything.  Here’s what will work for sure. Paint your hot coat and gloss. 

 

Adhesion with spackle and paint is not an issue.

  1. Have blank with holes and gouges

  2. Fill holes and gouges with light weight Sherwin Williams spackle

  3. Sand blank smooth with 220 grit

  4. Tape off stringer and spray blank off white (or color of choice) with water based acrylic paint

  5. Glass, hotcoat, sand surfboard as usual

  6. if more work to hide is needed, then spray sanded hotcoat with a fog of matching color. Do not apply heavy color coat. … and then gloss over…or use automotive 2 pack 

  7. buff out

  8. surf or sell.

  9. My recommendation is to chuck it in the trash and go get a good new blank.