Beveling Fins
Epoxy
Fillets
Internal Fillets
Masking Nose Cones
Miscellaneous
Paint
Painting Stand
Visual Fin Alignment
Why Use Wax?
Things That Didn't Work

The Proof is in the Pudding
The primary concept is to create a mixture of epoxy that is light enough and thick enough to retain it's shape and give you plenty of time to work with it.

For epoxy, I mix West Systems 206 and 105. I don't use the West System pumps, which make about five times the amount of epoxy I typically need. Instead, I transfer resin and hardener to squirt bottles. Usually, I mix up 4 drams of epoxy.

While the mixture is pure epoxy, I pour a few drops of it in the fillet areas. Then I use a paper towel to work it into the surfaces.

My mixture for Epoxy Pudding is about 30% epoxy, 30% microfibers (for strength) and 40% phenolic Micro-balloons (for lightness) by volume. I add the microfibers first because they mix more easily if added first. Next, I add the phenolic micro-balloons, a little bit at a time until the mix has the consistency of a thick milk shake or pudding. The Prather phenolic micro-balloons (PRA700000) give the epoxy a deep reddish brown color. Lately, I've experimented with colloidal silica. It is extremely light, but somewhat hard to sand.

The colored epoxy has a couple of nice side benefits. First, it is much more visible than clear epoxy, so you can see everywhere the epoxy is while applying it.
Second, it's much easier to see while sanding.

Pour the thickened epoxy mixture in the fillet areas and shape the fillets by running the PVC pipe the length of the fins. Run the PVC pipe around the leading and trailing edges.

I start from the back as shown and work forward in about 10 seconds. Then I place the PVC at the back again and complete the trailing edge. I go extra slowly on the leading and trailing edges to avoid pulling the epoxy upwards while taking the "corners".

Clean the PVC pipe frequently during the session with as paper towel soaked with alcohol.