Got it. More like slots. I'll try it with table scroll saw. Richard Dierking <richard.dierking@xxxxxxxxx> wrote: >I've been using a scroll saw to cut the grooves. You could also use a band >saw, jig saw, or hacksaw. I had an extra fin for my recent project and >attached a photo. It's 3/16" Lexan, so sorry it looks a little weird in >the photo. However, you can see the cuts. After the cuts, I blow out all >the debris with an air compressor. Also I use the compressed air to clean >the MMT after roughing it up. > >This greatly increases the amount of surface area for the bond. > >Please let us know how the fin attachment works. > >Richard >On Sun, Aug 19, 2012 at 11:14 AM, Mike Ostby <mdostby@xxxxxxxxxxxxxx> wrote: > >> ** >> I'm going to try Richards suggestion today regarding fin attachment. I'm >> scratch building my first dual deploy and today is fin mounting day. It's a >> 4" BT with a 54mm MMT so there's not a lot of room to lay up fiberglass >> - fin to MMT. (They will be glassed to the BT). So that I understand it >> correctly, I need to "notch or groove" the root edge of the fins many times >> aprox 1/8" deep? Thus sort of creating a serrated edge giving much more >> surface area for bonding. Thinking of just using a bench grinder (the edge >> of the grinding wheel) to make the notches. Is this the idea Richard? I've >> not epoxied the aft centering ring yet so I'm able to still apply fillets. >> >> Mike Ostby >>