I have read most of the posts in this forum but am doing my first fiberglass project and wanted to throw a couple of questions at you. I am making a simple plug. Basically it is a square box (5"X5"X2.5") box made with a plywood base and balsa sides. I am planning to paint the box with a primer base then a coat or two of paint. Then I want to use several coats of car wax (without silicone), then build my fiberglass layers over this base. I figured the paint would help smooth out the box.

Will this work? I would like to use the car wax due to availability and cost. I can’t find PVA or any of the waxes made specially made for releasing. I am going to be making only one or two of these boxes for now and don't really want to put out a lot of money for this project. Since it is a plug and not a mould, I shouldn't have to worry about fisheye problems since I will be painting the outside.

What kind of paint should I use when the form is finished? I am probably going to bang the box around a little bit and would like a paint that is durable.

Thanks for your help. I am kinda excited about working in this medium

I've used automotive 100% Caranuba Wax, but it takes multiple coats of it, 6-10 in my case. I'm still a novice at this, so your mileage may vary. I purchased Evercoat liquid PVA from my local marine supply store (West Marine). They also sell West Epoxy resin and mold release wax too. You might want to look up a marine supply/repair in you area.

Here is a link to my thread, pages 1 and 2 show the products I used. http://www.rcuniverse.com/forum/m_6794670/tm.htm

Hope that helps.

-Jorden

if you don't taper the box you'll play hell getting it to release regardless of what you put on it.

When I wanted to make a one-off cowl mold a few months ago, I was in the same situation. After a little research, I discovered that Johnsons Paste Wax is almost (if not all) 100 percent carnuba wax. My plug was constructed from the green florist foam, but the surface was pretty unstable, so I coated it with finishing resin. I still wasn't happy with the plug surface, so I covered it with aerocote lite, and then applied 7-8 coats of Johnsons paste wax. Although it was a little sticky getting the mold off the plug, it worked adequately. I then used the Johnsons to wax the mold, and again it worked adequately. I haven't tried to pull a second cowl yet, but I'm guessing it will be a little easier the second time around. For release, I went to a local craft store and found a spray mold release (I think it was in the ceramics section). It doesn't say what it is, but it looks like its probably PVA. A 4 oz bottle cost a few bucks, but it worked along with the Johnsons paste wax.

Brad

You could cover your plug with Monokote or similar heat shrink film, and possibly get away without much release media.
I have also heard of people using hairspray for release, it is pretty much like PVA.

Lars

Kiwi natural shoe polish works pretty good as a release agent in a pinch.