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C4 fins- some assembly required

Thread Status: Hello , There was no answer in this thread for more than 60 days.
It can take a long time to get an up-to-date response or contact with relevant users.


Dairyland diver
Apr 7, 2001
I just got a new pair of C-4's from DIVEINN!:D

They didn't come assembled.:(

Everything seems to fit together just like my plastic fins, blades pop into foot pocket, screws go through blades to attach.....

I was wondering if I need to do anything else special because of the carbon fiber blade???

Also, do I need to coat the screws in anything so that they don't wear on the blade??:confused:

Thanks for any advice that you can give me.


Congrats on your new fins. Use a washer and that should relieve any stresses on the fin. Just don't let anything aluminum come into contact with the carbon, though - galvanic corrosion.

You can also use tie wraps and thread them through the screw holes if you plan to change blades frequently. This works for a certain freedive instructor we both know.

Peter S.
Galvanic Corrosion

I have got the Omer Alluminiun SPeargun which has an alluiminium muzzle directly connected to a carbon fibre barrel. Will I too get this corrosion or not?

What steps can I take to avoid it?

Happy New Year

Shane :friday
galvanic corrosion

When I first read Peter S post about galvanic corrosion where carbon fiber and aluminum meet, I thought it was B.S., but in the New Year spirit of Cliff E. I decided to do a little search on it and not shoot my mouth off. Seems Peter S is right. The galvanic scale is different enough to make galvanic corrosion a problem. Seems several carbon fiber bicycle makers are insulating their carbon fiber tubes from the aluminum connection by wrapping them in fiberglass at the connections.

Omer may be doing something similar. It would be hard to tell with the naked eye. If bicycle manufactures are concerned about it than anything going in saltwater out to be more concern.

Sorry I doubted you Peter!
Just picked mine up this evening. Will try them tomorrow.

Mine were pre-built. The guy in the shop has mounted hundereds of pairs and he doesn't use anything but the screws. I quizzed him but he said they would last forever...?

What stiffness did you get? Are they your first carbon fiber fin?

Let us know how you like them.

I got the 40's with the Spetton foot pockets. I also own a pair of Sporasub Pure's. I like the Sporasub foot pockets better and will put them on the C4's as soon as Diveinn gets restocked with my size.
The fins feel good. I tried them out on Monday in about 20' of water. I know that it wasn't deep, but it didn't have any ice on it so I had to take what i could get. They had some nice power and my dive buddy, Ted, thought that they had a nice arc to the blade when I kicked.
The reason that I asked about mounting them was because of the Sporasubs that I have. They seem to have some kind of caulking holding the blades in- along with the screws.
If the screws alone will work I consider that a bonus. This way I can switch things around whenever I want to.

Which foot pockets did you get and which blade did you buy?

I got the 25s.

This was the strong advice of the shop owner for a first pair of carbon blades.

I got a good price, so I can (just about) afford to have made a mistake...

If you feel more comfortable with washers then I would go for it. I have no idea if my screws will damage the blade. I'll let you know!

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