Here is a series of pictures that show the steps that I went through to make the fin that is going on my latest board project – a 10’ old school balsa gun.
I started out by gluing together some balsa and mahogany. I used the same mahogany that I used on the tail block of the board, and the same balsa that I used for the board. You can see at the far end of the table is a piece of 1/16" thick G10, and a couple of pieces of 4 oz fiberglass.
I made a sandwich of wood + fiberglass + G10 + fiberglass + wood. I used RR epoxy to glue it all together. I had to put the sheet of G10 at an angle in order to make it fit my template. The top was brushed with epoxy, so that I could easily attach a template to it with Super 77 spray glue.
After the epoxy hardened I cut out the outline with a bandsaw.
Below is a masonite template that I stuck to the blank using Super 77. Note: I covered the bottom of the template with blue tape before spraying, so that my template wouldn’t get gooey. A flush trim bit on my router table allowed me to easily clean up the outline.
Here’s the side view.
Before foiling I drew some guide lines.
Here it is all foiled. I used 220 grit on a 6" PowerPad. In the past I used rougher grits, and found that I was removing too much material too quickly. The 220 allowed me to go just slow enough to have a sense of control.
Here’s another angle.
Next step: I’m going to apply a cheater coat of epoxy to the fin, and then glass it to the board.
This is the third board where I have made fins for it. I continue to improve my build process, and am getting faster. I am always open to tips and suggestions.