CLCboats.com has some great HOW-TO content, including this info on using Peel Ply. Read our excerpt, then head on over to the site for more images to help guide you through it.
CLC says, “We’ve written before about the challenge of getting smooth surfaces with epoxy and fiberglass. It takes at least three coats of epoxy to “fill the weave,” and then hours of sanding to get to a surface finish that’s ready for paint or varnish.
What if you could skip two of the three coats of epoxy and most of the sanding? Well, you can. Sometimes.
“Peel Ply,” also called “Release Fabric,” is a synthetic cloth that you drape over your epoxied surface as the epoxy sets up. Once cured, you can peel off the fabric, and what’s left behind is a perfectly smooth surface that’s ready for a quick sanding, or for the next round of epoxy. No runs, no sags, no low spots.
Not only is the surface under the peel ply nearly perfectly smooth, it actually has a texture that improves adhesion if you have anything else to stick to it. We use it here whenever we can.
Like all things, there’s a downside to this miracle. Peel ply isn’t stretchy like fiberglass, so you can only use it on really flat surfaces. Hatch covers, for example. Or the components of a stitch-and-glue boat that haven’t been assembled yet, but which are pre-coated in epoxy and/or fiberglass prior to assembly.
If you try to get peel ply to conform to curves, you might end up with wrinkles in the peel ply. And the peel ply will cast those wrinkles in solid epoxy, leading to a horrifying sanding session.”