Learn how to install box fins on a surfboard and how to place them as well in this free how to video on making a surfboard.
Yeah, when it's finished shaping then I thin it up to the glasses then they put the fin holes in at that point. Now the big box on the bottom they put in after the boards glass, 'cause any time you deal with a stringer it's so hard compared to the foam. You don't want it to rip a big chunk out of your board. We had a leash plug, so if you go surfing and your board is attached to your foot, put a good string through there so it doesn't break. And put the fins in also, just put over the top, we put it a layer to hold the fin box into the board so it's very strong. These are removable fins. That seems to be the wave fins are going these days. The fin is put it with an Allen Wrench. I'll show you. It's just screwed in. It comes out, got a little clip in the back and a little notch in the front. So it goes in like this and you just tighten it down. This is a side fin. Now this board can be ridden without the side fins so if the guy wants to ride it as single fin, he can take these fins off with relative ease. And ride it as a single. He can put a bigger single fin in. Fin placement is determined by the length of the board and what they want to do. I have a chart I just came up with many, many years ago and I follow that chart depending on the length of the board. Like a nine foot board I go fourteen inches off the tail. A ten foot would be fifteen inches, eleven foot would be sixteen inches, twelve foot seventeen inches, off the tail would be my upper fin. A lot of times on the bigger boards I don't put side fins because you don't really need them. It's fifteen inches off the tail. See the little marks here? So from fifteen inches here I move up four inches 'cause that's the base of the fin, and I set the fins in a quarter of an inch off of the inside mark. So if you look from the back of the board, the fin here, this angle here, you took a string would go right to the tip of the nose.