making some prepreg carbon fins

so im here at work and i have some free time during my lunch break. so i deciede to make my center fin for my 7’ fun board which ill be posting pics of soon, im working on the clear coat right now . its a thruster setup and i have tons of scrap 6oz prepreg carbon and 1/8 inch high density foam. i first cut my fin shape and put a layer of carbon between them and debulk the two halfs together in a vacbag. pull and shape the foam. then im puting 2 layers of 6oz prepreg carbon over the whole bit starting on the leading edge and stretching it over the whole fin so that there is no seem on the leading edge of the fin. and then off to the oven for 2hours at 260 degrees. now i have a bomb proof fin. so over all the whole fin is a little over 1/4 inch thick. just wondering if anyone else out there has used prepreg and does the surf industry use this stuff also cause prepreg is so easy to work with and so clean.

alright so heres an update on the fin, i just pulled it out of the oven and weighed it and it weighs only 28 grams not bad for a 4.5x6 fin. also this thing is so strong would not budge when i tried to bend it my outer fins are already made i did them at home out of blue foam but the good stuff i forget the density on that stuff but its pretty high its not the 60 i think it the dow 40 but there both made the same weigh but they were wet layup.

Cool. Is that a glass on fin?

Would love to use prepreg but its limited to making fins cuz surfboard foam typically cannot handle the cure temps.

Too stiff a fin doesnt feel great imo…a bit of flex feels and performs better.

Also, wondering about future delams cuz the foam is very pourous.

But thats a super light fin you got there, interesting.

actually its not a glass on fin its made for a future fin box. and the foam i use can handel 260 degrees and over 30 hg. we have it in 1/8 sheets so i just put together with a layer of carbon in the center and two layers on the outside. which makes a perfect fit in a future fin box. i guess theres a little flex, i havnt surfed on these fins yet so well see what happens. but right now im developing a new style of fin box so ill be posting some pics of that also, i think i have somthing that no one has ever done and it will make changing fins a breeze. delaming will probably never happen. im a composite tech building uavs and i have been doing it for over 3 years and the stuff i deal with is top notch and the things i have built in the past have never failed. for instance i built a long board skateboard out of 20 layers of 6oz carbon with honeycomb seperating 10 on each side with camber built into it with no concave and the board is super fast and responsive. also i drilled a hole right behind the front truck for a mast foot to be mounted for land sailing.