I have been making a few fin panels and fins recently but have only been making single fins for standard longboard box’s so it has been relatively simple going.
I am making a set of twin/keel hybrid fins for a friend to fit futures box’s, out of a panel of 36 layers of 6oz, so i have plenty of wriggle room, was wondering how you all go about getting the desired cant in your homemade futures fins? im struggling to think of ways to get it accurate and repeatable at the moment. Any help would be awesome! cheers
The canted bases of futures rail fins have kept me from considering using their system.
I am a firm believe in a very solif finbone to footbone connection and I hate how FCS 1 and fcs2 and anything with grub screws on the side, basically requires the grub screws push the fin base against the far wall and bottom of the box.
I much prefer the grub screws merely keep the fin from lifting out of the box, rather than get loaded when turning.
In my quest for removing surfing loads from grub screws I make the fin tab thicker, and it is basically impossible to sand them so they fin base touches the entire receptacle. So I developed a tablesaw method.
These are for Probox Hawaii fin system:
This method for rail fins required sliding the flat side of the fin along the fence, and lots of preceision aligning of fence to saw blade. I’ve made a fence sled, that holds a center the fin tightly, but have not perfected it yet. Perhaps this gives you some ideas regarding achieving precise thickness canted bases on futures fins.
I have done the following when building a set of bonzer runners with FCS tabs that I needed extra cant on.
Lay up your fin panel to your desired thickness, then build up additional thickness in the fin base area on the outside of the fin using appropriately sized strips. Once you have enough additional thickness on the fin base on its outside face you can then set up a simple jig and sand the appropriate angle onto each side of the fin base to give you the cant you want. Once you’ve done that you have to true up the bottom face of the fin base to be 90 degrees to the sides of the fin base.
Thanks guys that was just what I was after, fresh perspective to push through a mental block. Will throw together a jig tomorrow. If anyone else has any more ideas/advice/experiences I’m all ears.
Cheers Ricky, the clear halo’s are just from laying up a clear layer in the middle of the fin panel, so I’d mix up enough yellow to do say 24 layers of glass, catalyse half the yellow and lay up 12 sheets, then lay up 12 sheets clear, then catalyse and lay up the final 12 sheets yellow, the more sheets of glass you do clear the bigger your halo is, hope that makes sense.
Very clever Kbrebs, and a nice way to do it! But surely the patterns must have been put on after foiling. Did you glass over the patterns, or just spray with clear coat or something like that? I’ve never made them this way, and want to give it a try.
Thanks Ricky it’s a real easy way to get a nice looking fin that’s a little different. All the fins are just foiled and left as is, I just wet sand to 400 or so and surf them. I don’t seal them with anything as you tend to lose the foil lines from the layers of glass which I really like. The one with the pressed flowers was an absolute ball ache and I had to laminate a bunch of extra layers of glass overtop the flowers to get things foiled nicely.
I haven’t made a lot of fins, but I’ve modified a handful. For futures fins I would make a fin like normal, lay up glass sheet, cut out, foil. Next I would carefully tape off one side of the tab, outboard side for normal fin cant if I remember correct, making a dam of sorts. Mix up the resin with an appropriate filler, I use chopped up fiberglass cloth, and fill the dammed up tab area. This should build it up enough to sand in the cant into the tab. For repeatable results I would build a sanding jig. A fat wedge at the cant angle for the fin to lay on and sanded against flat sandpaper. Like a miter shooting board for woodworking, except the plane is a sanding block and the miter isn’t 45 but the fin cant angle. Hopefully this picture helps show what I mean.
WRC68 have you tried table sawing the fins before you foil them? When I do thick longboard fins, I will cut the outline, table saw them like a dado or rabbet, before foiling. The fin blank ends up being horizontal flat on the table saw because it isnt foiled and I find it easier to take equal amounts off of each side. After the tab is cut I foil, glass, and sand to the fin to fit snug into a box.
