Re-setting glass on fins

General Discussion
1

I tried searching through the archive, but to no avail.

I need to re-set the fins on my board #1. After a few test sessions it has become obvious that there’s too much toe-in on the side fins.

Does anyone have any helpful advice on how to do this?

I’m assuming step one would be to remove the fins and then grind any leftover/protruding resin flush with the hotcoat. Then will it be necessary to strip any glass in order for the new lamination to adhere? Will roughing up the hotcoat with coarse sandpaper be good enough?

Also, when I originally glassed the fins on, I layed up 3 layers of four ounce cloth on each side of each fin. If I do this again when re-setting the fins, will the buildup become such that the fins are too heavy or begin to loose thier foil?

Any opinions or advice would be much appreciated.

Thanks.

2

The old fillet on the fin and the board has to be ground away. Be careful not to sand on it to long at a time or you will build up too much heat. Blistering over foam, just don’t do it. Sand(grind), let cool, repeat.

Toe-in? You didn’t give a board-length, type, outline, waves to be surfed, speed or manuverability desired, so all I can suggest is 2" past the nose.

‘Too much toe-in’ ? Longboard? Try 1/8", or maybe 3/16". That’s all I can suggest with no info whatsoever.

3

This is pretty much the same as replacing busted off ( or busted loose ) fins and here’s how I do that;

As you say, cut 'em loose. My tool of choice for this job would be a 7 or 8 inch sander grinder, with a foam pad and a new and relatively coarse disc on it. Use what you have, of course, and adapt .

With just the edge of the disc, lightly go into the inside corners and cut away the fillet, where the fin meets the bottom. Do this on both sides. The fin, then, should come away easily.

Carefully, and with sharp, new and coarse-ish (around 60-80 grit) disc, grind the bottom flat. I’m kinda harping on a new and coarse disc, thing is that as Ozzy mentioned you can most definitely get heat buildup from a dull or clogged disc and this is how to avoid it.

Ok, note I say just grind it flat, no need to remove any more than you have to. In fact, flat-ish is good enough, just grind away the fillet and such that sticks up. Don’t get any further in than the hotcoat. 'Cos you’ll be laying plenty cloth over it when you reattach said fins. If you want to, I suppose you could add a diamond or lozenge shaped patch of cloth on the bottom, both sides, for reinforcement. It can’t hurt.

Now, you did a good job setting the fins. 4 oz x 3 is good enough. But if you were to go with another 3x layer over that it’d prolly be excessive. So…

For the no fun and kinda hairy part - put your fin tips in a vise or similar and grind around them, getting down to the original fin on both sides. I like a woodworker’s vise for this, but you can get away with using something as simple as a clamp, a block and a saw horse. But do it securely, you don’t want something small and sharp like fins flying around the shop. It could kinda smart, being as they are at waist level and all. Also, be careful with the edges, they can catch and shred a sanding pad awfully quick.

Flip and carefully get the tips, then glass 'em on again as you did before.

Hope that’s of use

doc…

4

France S Cutti,

May I add my 10 cents here, the guys got the removal thing down here. Usually i’m so pissed off that i just kick’em off, you’d be amazed how easy that is compared to grinding and taking your time.

Recommendation: Anyhow, what I recommend you do is give Robin Mair a call or e-mail at ProBox Hawaii and pick up one of his fin installation kits. With his fin system you can adjust fin cant & move the fin cluster by 1/2 inch in each box. What you cant do is mess with the toe in, or at least it’s not set up that way, but if you must you can slightly grind down a fin tab on the inside edge, and put a little shim in the box. And the installation is really, really, really easy, I mean super really silly easy. My point is that since this is board #1 and your just learning about fin placement etc. you should give your board a lot of options. What’s a dog now might not be so later after tweeking, but it might take quite a bit of tweeking until you understand foil, rocker, fin placement combos.

Who knows, they don’t call’em “Twin Spins” for nothing!

Case in Point: A board I made for a Hawaii trip worked great over there, lots of rocker fins set G-7 fcs @ 1/16 toe, 6% cant, spread out the fin cluster. Board sucked here in San Diego when I first surfed it, felt like I was pulling a kelp ball from my leash. Board was loose, but slow…too much drag for our SD waves. I changed out the cant inserts to 4%, tighten’d up the fin cluster by pushing the back fin forward, and the front back. And changed out the fins to GPR’s. Now the board is super fast, and turns with a real positive feel, all I did was free up some drag in the rear of the board, nothing to do with toe in. If I was trying to do that with glass on it would have taken 4 trys… I would have thrown the board away. Oh yeah the Pro Box accepts FCS, or just about any other fin system, you can even buy glass fin blanks and make your own. And if your wondering I don’t work for them or anything.

-Jay

5

Thanks for the responses.

I designed the board for soft beachbreak up to headhigh and a half. It’s dimensions are 6’0x19.5x2.25, with an 8" rounded square tail, full rails, and thickness carried through to the nose and tail. I’ll try and post some pictures when I get to my home computer (I’m at work right now).

I toed the fins in to 1" outside the nose and canted them 6 degrees. It was one of those things that you don’t realize was stupid until after you have done it. I’m guessing that sort of toe-in is probably more appropriate for a gun. The first few surfs on the board confirmed my suspicions. It was slow surfing down the line, and super squirelly when turning. I’m planning on experimenting quite a bit with this board. First by resetting the toe in to 2" outside the nose, and then possibly reshaping the fins (I think they might be too big as they are), and then possibly even stripping all the glass and reshaping the board. Might as well experiment and learn as much as possible!

Thanks for the advice on probox. I am going to be looking for a fin system kit in the near future, it sounds like probox would suit my needs well.

Daniel Francescutti

6

Ok, here’s some pictures of the board, before and after glassing. As I said, I think the fins are to big, I’ll most likely end up reshaping them or at least making the back fin into a trailer. But first I’ll be setting the toe-in to 2" outside the nose and testing the board again. It should be interesting to feel the differences made by changing one variable in the boards design at a time…



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7

Question… how do you feel about twin fins? if you like 'em… kick off the center fin and sand it down then re-hotcoat the area…

thats just my two cents…

also, in spite of the tow in problem, how did it feel on the wave? hard to paddle in? slow on takeoff? was it sluggish in turns? did it turn too fast? slideouts?.. describe the feel of it and I bet you will get a flood of good responses.

8

It’s not that hard at all. Just take your time and go step by step and b4 ya know it, it’ll be a done job.