I laid the glass strips on over the clay. You can see that the fiberglass was wider than what I'd want the final fairing. It'll get trimmed later. The white cloth you see covering most of the part is peel ply.

Peel ply is just a cheapie nylon cloth that you put over the last layer of fiberglass. Once the resin cures, you peel the peel ply off the fiberglass part. The peel ply helps the resin to fill in the weave in the cloth and leaves you with far less sanding work. Peel ply is your friend!

In this picture, the resin has cured, the peel ply has been removed and I've started to sand. I didn't pop the piece free from the mold quite yet because I decided it'd be easier to sand with it held securely in place on the wing.

As much as possible. you'd like to have a sanding block when you're sanding fiberglass. Without something between your hand and the sandpaper, you're likely to just amplify wavey imperfections in the fiberglass part.

I found a large piece of PVC pipe that was the approximate radius of my wing root fairing. I then glued Norton 80 grit sandpaper to the pipe and used it as a sanding block. It worked very well.

Once I had sanded until I was blue in the face--actually white, and covered in dust--I pried the piece from the airframe. This is what it looked like. You can see I'll need to pick all the clay off the part and then trim it to final dimensions.

The clay actually comes off fairly easy. I wasted a little bit of clay because the PVA mold release tends to stick to it, but I was surprised at how little I actually wasted.

I've picked off all the clay mold and am now ready to trim the piece to its final shape.

I use a combination of a die grinder with a cut-off wheel and a Dremel tool with a cut-off wheel to trim fiberglass parts. They work well and make nice cuts.

I realize this is the right wing, but here is the fairing after it's been trimmed and after a little sanding.