Experiments in Homemade Composite Tooling(surjan.substack.com)

2 pointsby as89hace 6 años1 comments

surjan.substack.com

Experiments in Homemade Composite Tooling

https://surjan.substack.com/p/20-experiments-in-homemade-composite

1 comments

From the article: "I have sprayed PVA before in college, but I didn’t have much success then either."

I have had good success with PVA, there is a trick to it. The initial sprayed coat should be applied very light and thin, such that the PVA is very nearly dry when it reaches the surface. Allow this coat to dry completely, then apply heavier second coat to fully wet out the surface. The thin, dry tack coat anchors the PVA and helps it to wet the surface, rather than beading up on your polished and waxed mold surface.

Brush application is very difficult. A sponge brush is a good choice for PVA application, dab rather than using a sweeping motion. You'll want to do this in a single coat, any attempt to brush or dab a second coat will cause the first coat to wrinkle, roll and/or rope.

Edit for clarification.