how to make carbon fins?

valen35 said:

I need to know the materials to use to make carbons fins?, some one can help me out please.

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Hhhmmmm,....... Where to start? I started this quest serval years ago and now have my own fin company. Who knows where you will end up?

In any case, it's pretty easy to make a bad fin. It's pretty hard to make a good fin. There are plenty of YouTube videos out there that can show vacuum or resin infusion techniques. Your craftsmanship will matter in the final look. I prefer compression molded, but this is totally impractical for the garage made fin
Despite that, it is the materials is that is very difficult.

First, it's very expensive to make your own. It's a fun project, but you won't save a whole lot of money, if any. The margins in the industry are razor thin for composite fins. Standard epoxy resins off the shelf from most places will not work well and are very expensive. You need resins that have a special flex to them, or they will "white out" from compressive forces as they flex and compress. Eventually, this delaminates and breaks. You can still make your own with the standard epoxies out there, and they will work for a while, just don't expect longevity or that nice 360 degree bend you see on the pics! If you use resin infusion, you must use a very low CP (low viscosity) resin. Around 100 works with a good vacuum.

As for fabric, standard 6 oz. E-glass works for fiberglass fins. For carbon, it's bordering on proprietary secrets, but you need about 60% of the fabric weight you use for fiberglass. Standard plain twill cloth works, but not really ideal. Custom fabrics are often used since the most common weights just dont work well to establish the proper transition in flex.

Lastly, the rails.......hmmmmm.....you can buy some rails to glue on the edges from Neptonics, but you don't really know how well they will fit your footpockets. The is a certain amount of standardization in the industry, but they all measure different and they all fit different with various pockets. Then there is the issue of gluing and clamping them. It's takes some effort. Standard cyanoacrylate glues work fairly well for binding, depending on the material of rails you end up with. Urethanes, like Gorilla glue work well, but set so slowly, that it's painful. Plus, some of them expand which is good for filling gaps, but you end up with a larger bonding gap and thicker, brittle material on a very fluid, flexible part....a recipe for failure over time. Cyanoacrylates with a good clamping system is the best system.

I hope I have not discouraged you too much! It is fun and you will learn a lot along the way. You can PM me if you have questions.

Hi valen35,

Have a look at his thread by Zmago:*http://forums.deeperblue.com/bi-fins/86109-selfmade-fiberglass-fins.htm . Some awesome info there.

Also do a search in some of REVAN's posts as he provides a in depth comparison on fiber glass vs carbon for fins.

@Moana what's your fin company's name? Sounds like you produce a great product.

landshark sa said:

Hi valen35,

@Moana what's your fin company's name? Sounds like you produce a great product.

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I don't want to infringe any rules of the forum, but I think since you asked, I can reply!

My company is Moana Waterman | Freediving Carbon Fins

Moana is a new company, but I've been making fins for a while now, but for the past two years have been working to take it to the next level and try to make the best fin in the world and create a philanthropic enterprise to benefit coastal communities.

The main advantage of my product over other fins is the Carbon material and layup. Instead of plain cloth (0/90 degrees), I use a variety of weaves that give an omnidirectional dispersion of force. I don't have any data past two years. But so far, no signs of fatigue or breakage. Ultimately. This must reduce fatigue and breakage. Also, radial cut tapers reduce step offs to fatigue or break along. This is all information you can use when making your own if you choose to do so! Lastly, I am proud to be an "insourcer.". That is, I brought manufacturing back to my homeland...the USA, where we have fair labor, strict environmental laws and I can control the quality tightly.

Lastly, I like a lower height rail so they don't get damaged so easily and don't buckle when flexing. The buckling can cause turbulence. The height I use is high enough to effectively channel water and stabilize the tracking, yet not damaged easily ando turbulence.

Again, food for thought if you decide to build your own or are shopping.

Cheers and Aloha to all.

Must say they look really good Good luck with the new venture.

I take it the fact that you compression mold the fin gets rid of the mat / textured finish caused by the peel ply and flow meduim we see on some of the vacuum infused fins?

This thread may well interest you ..... http://forums.deeperblue.com/bi-fins/86109-selfmade-fiberglass-fins.html

landshark sa said:

Must say they look really good Good luck with the new venture.

I take it the fact that you compression mold the fin gets rid of the mat / textured finish caused by the peel ply and flow meduim we see on some of the vacuum infused fins?

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Well, a good resin infusion fin should have a perfect finish. You will see a peel ply texture, but that is tailored from smooth to rough, depending on your peel ply. Resin infusion, as you probably know, allows you to lay up your fabric dry which lets you lay it up perfectly aligned and no distortion of fabric! That's a good thing cosmetically! Also, there will be no surface cavitations from air bubbles, as all surface bubbles are drawn out through the peel ply and into the bleeder cloth. Hopefully there will be very little air before the resin even enters the layup if the bagging was good. Resin infusion products look good! The downside is that resin is imperfectly removed and the result is slight variations of resin/fabic ratios and thickness. Generally, this doesn't make any difference to the end product.

The compression molded product will hopefully have straight fiber bundles, but they usual undergo a small degree of distortion as the resin must squeeze out through the sides of the mold moving resin potentially all the way from the middle of the part to the edge! To address your question, you will get a smooth or textured surface, depending on how you prepare the mold face. If you use smooth mylar film, you will get a smooth finish. If you use a textured film, or a sandblasted or milled mold face, you will get that texture. One thing about compression molding is that you may have some small cavitations in the surface from air that gets trapped on the surface. The layup will be airfree and perfect, but not always the surface. This is one way you can usually tell if something was compression molded. Sometimes it is perfect and you can't tell. My product has a light epoxy matte spray to knock down the shine a bit and helps to fill in any little cavitations should they occur. the nice thing is that the product has exactly uniform thickness, side to side. The thickness of the blade is taken into consideration in milling the mold, so it's exact everytime.

I hoped that helped!