Slick sand
 

i picked up a product called slick sand. It's a sprayable polyester filler, high building. I am making a plug and am ready for panel lines. My question is, can I sand and polish this polyester product to use as my plug surface with wax and mold release? Or do I need to top coat it with something else?

What are you going to make your mold out of? If you plan on using epoxy (Highly recommended) do not use any polyester products in your plug. While it can be done successfully, the usual result is styrene migration from the polyester to the epoxy causing major release problems.

Scott

Agreed, I too recommend going with all epoxy products. In fact I am at the same stage of a project as you. I have a wood plug all glassed and sanded smooth and ready for primer. I agree that one of the polyester based filling primers would make the next step much easier but I have chosen to go with Klass Kote epoxy primer. If you do use the polyester based primer you will need to do a final coat of a catalyzed gloss coat such as a Klass Kote or a single stage auto paint. Even then you may have enough of the polyester solvents to work their way through the top coat and affect your release product.

Plug is foam wood glass. Lots of bondo. Some urethane primer. A couple coats of acrylic urethane to give me a hard surface. Was going to score the panel lines, but I've decided to use 1/32 tape. So I need a high build again.
So can I eliminate migration with a sealer coat? Or will I need to make the mould out of gel/polyester resin. I have lots of experience with this stuff, not much epoxy experience.

If it were me, I would switch to an epoxy primer or ar very least a urethane catalized primer. A couple reasons for this. First to avoid any chance of styrene mitigation but the epoxy primer will have less chance to react with the adhesive on your tape. After a few coats of that I would remove the tap and very carefully go over the lines with 1500 grit wet to break the edge a little and then spray a gloss coat of 30% thinned urethane clear. Let that set for 48 hours and then rub out any orange peel. After buffing I would let sit for a week and then wax with Partall #2 at least 8 coats and then mate to your parting flange.

I found some epoxy primer from painting my boat. Worked good. It's since been top coated with acrylic urethane. Came out really good I feel.
My next question is about surface coat. I was thinking I would just buy resin and mix aluminum powder and something like cotton flock for surface coat. It'll be way cheaper than an aluminum tooling resin. Thoughts?

http://www.rcuniverse.com/forum/scra...l-xp-67-a.html

I am going to try an epoxy clear coat mixed with graphite powder sprayed on as a surface coat. My next step will be to use laminating resin with graphite powder and cabosil. Cloth and resin will follow until enough thickness is built up.

resurrecting an old thread, but did the epoxy clear/graphite powder work as a surface coat?

I second that for the simplicity.