Crazy wood carbon composite fins

I’m actually suprised that the glass doesn’t fold into where the resin sits between the wood…

It would be the mold holding it taught across the gap if you know what i mean??

Great fins anyway!

A

The wood is paper thin. The gap between the carbon and wood is neglegable. The sandwitch of wood, carbon and fiberglass is extreamly thin compared with the thickness of the fin. There is LOTS of empty space which is just filled with resin. The glass cloth is all over the place, I dont know where it ends up in the fin when it dries, all I know is that the materials are layered in the correct sequence to produce the final design on the fin. Along the base of the fin, the glass cloth and carbon are all folded up into the mounting notches to add some strength. The process is basicly laying the materials in the mold while they’re caked with resin, get the bubbles out, squeeze and hope for the best.

Are you using chopped strand on some other type of bonder in the resin mix?

It seems that in those areas of filled resin that you are gonna have some serious problems with the resin cracking due to flex of the fin once you start riding it. Put the base in a vice and bend the fin and see what happens.

Why the two seperate pieces of wood instead of just one bigger one? It would weigh less than the resin and provide added stiffness and flex to the fin panel. Seems like it would be much easier and more consistant flex-wise if you used one piece of wood in there.

The fins look cool though.

I’m trying to figure out how I can use your technique to just make a Future base mold so I can mold the base onto wood-core fins once they are glassed.

"The fins look cool though. "

Thats why I made them the way I did. Just for looks. They are VERY stiff. Much stiffer than stock futures fins. Im not worried about them breaking.

Lawless,

if it is a shaped wood fin you can leave extra material for the base, make a template and just cut around it, leaving some room to seal it up with glass, also a small plate where the screw contacts the base may help keep cracks/water out. Sand or saw to get the cant angle on side fins.

No, you really need a mold or machining process to make the cant on Futures come out well…otherwise it won’t sit tight in the box.

My recommendation, Lawless, is to make a 0.25 inch wide slot box that is 3/4 inch deep (or however deep for a center fin). Use a glass stack fin tab that is close to the right thickness. Grind 5 layers of glass off both sides, and lam 5 layers of glass between the wood fin and fin tab to hold them together. That’s 5 layers, each side. Then, stick it in the slot box (plastic works well for the slot box, actually).

Set the fin angle relative to the box, and add resin to make the cant come out right.

Then, you should have a 0.25 inch wide canted fin tab, and you will need to cut the ends appropriately for the Futures fin system.

And keep making fins, I find it is a blast riding my own fins, and you will never learn more about how fins work than you will by making your own (provided you do more than just copy existing shapes, that is).

Im filling in the air bubbles with epoxy/glass fibers

I ran across this website today. The prop is made similar to the way I made my fins. Note that he uses a vacuum pump to remove air bubbles from his resin. I gotta try that. I’ll try hooking my shop vac up first and see if I get any results.

Carbon Prop

clear coat is on. Let em dry