Molded Carbon Fiber Fins

[Thundercloud]

I have been wanting to make this type of fin for many years. I have done some experimenting along the way, but never completed a whole set. Now that I have a 3D printer, I decided to use it to make a mold. Nike fins for 4” tube seemed like a nice size and design to start with. So far, I have made one layup. I still, have to add the pour-foam core, and trim some flashing.

 

[OKTurbo]

Very Nice! Much better than my attempt to mold fins in CF. I tried a vacuum bag set up and it worked...just not very well.

 

[Thundercloud]

Thanks. I have used vacuum bagging successfully once before, but it's a hassle. This time around, I made backing plates with studs. I layup two mold halves, add a peel ply and 4 bleeder plys to each, then clamp it all together. The carbon gets squeezed tightly against the mold halves, and the other layers soak up the excess epoxy. It's like vacuum bagging, but I use studs to draw it all together. After it cures, I remove the peel ply and bleeders, then epoxy the two halves together, using the studs to clamp it.

 

[Thundercloud]

I finally finished my first set of carbon fiber fins.

 

[Thundercloud]

Because the fin slots for these need to be diamond-shaped, I 3D printed a template. It has little notches front and rear so it can be placed over a simple line drawn on the body tube, taped in place and traced.