Everybody has a couple of those 18 gallon plastic tote/tubs laying around that cracked at one point. I cut one of those up. worked perfect and you can cut whatever shape.radius you want. cheap and disposable.

Plastic picnic spoons work good too.

I have been using cabosil with epoxy resin and then use a 1 inch paint brush that I dip in acetone from time to time to help keep the cabosil mixture from drying out. Running the brush long ways back and forth with a little pressure applied really adds a nice finish. If someone would like I can post pics.

Cliff