Spend a lot of time today to figure out how to dimple the doublers and the section of the lower and upper fin. I could not use the regular dimpler in the squeezer, bacause there is just not enough room. BJ suggests to just use a sinker for the rivets and put a layer of Bondo over it, but with .025" sheet metal, I did not like this approach. I made a small dimpling tool on my lathe and used it to dimple the fins, since I could only use the squeezer on 4 out of 27 holes on the fin. After making some test pieces and tweeking the dimpler dimensions, it worked quite well. The doublers could all be dimpled with the squeezer. I also drilled the two 3/16" holes where the braces for the fin will be installed later 7.5" and 5" from where the lower and upper fin butt together. The fin is now ready for final assembly. I will however take it appart one more time to debur everything, clean the chromoly spar weldment and coat it with a couple of layers of Zinc Chromate.
