I never liked this board with 4 fins, but hopefully I will like it now. But like I said earlier, I will test them as a thruster too.
The wood is glued to the glass panel using 5minute epoxy. The glass panel is made with UV polyester resin. And if I’m not mistaken it is 9 layers of 165g/m2 ~= 5oz glass (It is ± 1mm thick).
This way of making fins is quite labour intensive. Sawing the different contours takes a lot of time. I like the thickness steps because it allows me to foil the fin closer to the foil I want. (The contours are generated using finFoil). I’m already thinking of a better way of making these steps using a router and some jigs.
This set of fins is quite an experiment for me. It is the first pair of fins that I foil, it is the first time that I used UV polyester (I’m an epoxy guy), the first time I use 5minute epoxy, and my first try to bring finFoil in to practice.
I hope we can get the guessing out of backyard finbuilding some day (without the use of expensive hardware like CNC, …). There are a lot of proven techinques for surfboard building, but finfoiling has a lot of room for improvement.
Hmm, I noticed you carried the wood core down into the base of the tab - are you concerned about strength or delam if the wood takes on water with this setup? Most of the wood fins that I see (the ones that hold up best anyway) are typically all-glass for the tab(s) and the wood only goes down to where the fin is level with the deck
Time will tell I supose. The timber isn’t exposed and had a few layers of 6oz on each side before casting the base on. Laying up a spine first would definitly be stronger, but this has quite a long base for the height.
I came across a 'Trigger Brothers' 'Stinger' [yes , SINGLE fin !] , at the Longboard Shop here , the other day ....
I posted a shot or two on my 'Facebook' page , as I figured my brother [a collector of boards] might be interested ... being , also, that they are a Vicco company with a fair bit of history . [ Simon lives in Vicco]
I have a few ¾”-1” thick D-fins that I had templated to be glass on’s a few months back and have decided to mold bases to fit 10” fin boxes. I am not concerned with having the ability to move the fin fore and aft,but instead being able to switch out different style fins and strength . I am apprehensive about gluing a separate base directly to the fin as I worry about strength. I decided to cut a keyway in the fin to attach the fin base to hopefully help increase strength. After the glue up I plan to cut the base width down to 3/16” and insert into a fin base jig( copied off someone here, my apologies, I forget who). I have the fin/base glued up and the fin base jig completed. Next up, whittling down base width, pouring exterior fin bead, foiling, pouring resin/chopped glass slurry into base jig, and glassing. Fun project!
I gave the thick stuff to Robin Mair. I could use a couple of fins to fit those Twinzer boxes I have. I still have a 3/8" slab with a piece of koa cut using the 9" Greenough 4A. Haven’t cut it out.
That softtop looks cool, a Haut! Shouldv’e got all of them huh?
I asked Bill Thrailkill for a little help in getting a reverse d fin made. My questions for Bill were more specific than what depth and length I should use. He replied back with grace and kindness and requested that I post a picture when I was finished.
What I have is a fin that is 8.75’’ deep and 10’’ base. Made with Balsa, Mango and black glue lines. The Black glue was made from black food coloring and glue. I thickness sanded the outline down to 3/4’‘. Bill recommended a thickest part of the foil be placed at 40% the chord length from the leading edge of the fin. So, approximately 4’’ (0.4x10’‘=4’').
I have a mold to make the fin box and used resin mixed with short pieces of roving to give strength. Glassed with 4+6 saline.
Problems I encountered were getting a smooth and consistent foil due to a hard wood and soft wood. Where the two woods meet there is a divot due to sanding.
Overall I am happy with the fin. No ride report yet but as will all my fins anyone is more than welcome to give it a go.
The other fin in the pic is your basic run of the mill high aspect ratio fin made with Sapele. 3/4’’ stock which is 12.5% the base chord with the thickest point at 30% leading edge and a small halo. Cheater coated with resin mixed with 25% Styrene and the same glassing schedule as the reverse d.
