> Awhile back there was a post from someone wanting to know what to use as a
> fiberglass mold release agent. The outfit where I got my epoxy and cloth
> from had a brochure on waxing fiberglass plugs and molds in which they
> mention two products, OP-600 and OP-500 mold release wax, made by Oscars.

> The brochure states that the wax has a high carnuba content and is similar
> in looks and application to car wax. As car wax is readily available to
> everyone, this would solve a lot of problems, if it worked. Car waxes come
> with varying amounts of carnuba in them and, as usual, the higher the
> carnuba content the higher the price.

> The brochure said; five thin coats of wax applied in alternating
> directions, let each coat dry for 1-3 hours then buff to a shine before
> applying the next coat, let final coat sit for 24 hours and buff. I don't
> know if we would need to be this meticulous as we only use our molds a few
> times and the finishing surface isn't that important to us.

> Has anyone tried carnuba car wax as a release agent?

> Ian

> PS. I also picked up brochures on making plugs and molds.

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Mold Release:

I often use DeraKane 8084 vinylester resin by Dow, so a very good, multi-layered mold-release system is needed, that has no flaws (a lesson learned the hard way). I've tried the recommended Meguiar's mold release wax and found it to be inadequate by itself for resins with high bonding strength. This type of wax does not work with PVA, as this green liquid beads up on the surface. There are several release wax brands that are designed to be used in combination with PVA and any pro supply shop can steer you to them. However, the best type of wax I have found for use under PVA, is Johnson's Paste Wax, available in many grocery stores. I buff it out by hand just a few minutes after application and allow 1 hour between coats. Three or four good coats of this should be used and two hours is enough to wait before applying the PVA. I usually brush on the PVA with a foam Poly-Brush, rather than spraying it. A little Pre-Val aerosol spray bottle is a cheap way to spray it, if you don't want to bother with a large compressor. Make sure that it's a real Poly-Brush or the equivalent, as some imitators make ones that are too squishy to use with PVA. I use multiple strokes, in both directions, on each area.

Steve McDonald