Waveset fin repair

Hello all, 

I recently acquired a really cool vintage board that I want to be a rider in my quiver. Unfortunately, I am frustrated trying to acquire an original or reproduction waveset fin. I found that people charge $150 minimum which to me is not worth it for this board. Instead I am going to try to fix this broken waveset fin. I don’t want to put a new fin box in it either, because I think the board is worth keeping all original. 

I would greatly appreciate some expert knowledge on how to fix this. I am leaning towards a quick fix because spending hours trying to make it flex perfectly etc. only to have the tip break again after a couple of waves would be a major bummer. See pics. 

Thanks for your input! Cheers!



I’m surprised no one has ever made a box  adapter to allow for the use of traditional fins in the Waveset box (I’ve never seen one at least). Probably not enough demand now to make any money.

that’s a good point. But for now, I’m focusing on adding some sort of material to the end of this fin. Not sure if epoxy resin, some sort of plastic, or fibre glass, etc. will be best, strongest and most cost and time efficient. 

Forget fixing the existing fin, and focus on making a new glass fin, with  a built up base to match the dimensions of the original base.    That is EXACTLY how I wouuld address your ‘‘problem’’ if it were mine.     Or, simply pony up for an original lexan fin.

Thanks man. I value your input on this. You def have some of the best posts on sways. I was hoping this would not be the answer just because I am not well equipt to make a glass fin. It would be very ambitious for me. I’ve always wanted to do it, but I don’t have a table saw nor do I have enough patience to take on that project. Also, ponying up $200 for an original is not something I’m into right now, but if I can find one for less I would buy one. I am biased because I enjoy restoring, fixing, etc. of existing things that would otherwise be thrown in the trash. It’s kind of rewarding. If you were to fix this fin, is there a way that would work best in as little time as possible? just to at least try the salvaged fin. Thanks again!

I have had success in fixing plastic things by using a dremel with a cut off wheel to cut grooves on each side of the break and saturate some  fiberglass roving or carbon fiber with superglue.  Not sure if superglue bonds well with polycarbonate/Lexan, but it does on Acrylic/plexiglass.


The successes include the bridge of sunglasses/ reading glasses and some hand tools like this razor knife’s plastic extra blade retainer.



Nothing I have fixed with this method has broken again.


I use this groove method on new wooden fins to to increase the strength of the base or the fcs fin tabs, and it works well, with epoxy.  I have not worked with PE resins in a while.  Epoxy is not good on most plastics though.


Hey thanks man. this groove method is pretty brilliant for strengthening the bond. Do you have any ideas for what material to use to create a new tip for this fin? 

I assumed you still had the top of the fin.


If it is advertised as Lexan, lexan is polycarbonate, Lexan is just a brand name like plexiglass is just acrylic.


you can get sheets of polycarbonate



I don’t think a repair will work. That said, if I were to attempt one, I would cut the fin off flush with the base, cut a slot in base, and slip in a replacement fin and attempt to find an adhesive to hold it in place. I would also run some pins through base and new fin insert to help secure it.

Polycarbonates are tough to get anything to bond to them.

I’d go more in the direction Bill T suggests. My own approach would be to make a mold from the existing fin with a tip filled in as the plug for the mold.

You can get a regular FU box and modify it to fit in that one, but it’s a lot of work.

I agree.  The amount of effort required to fix the fin, and the materials required to do it, not counting the labor involved and possible bad results, make buying a new waveset fin, even overpriced, the better option.

I’d personally  just install a FU box in the board and say FU to the value of the classic board.  If the perceived value is a big consideration then don’t ride it.  


Function beats all, and it appears lexan was not up to the task originally.  I’ve personally never seen a fiberglass fin break in such a location.

I just recently made my own fin.  The main tools I used were a drill press and a dremel.  Used spray glue to glue a template on the fin panel then used the drill press to drill closely spaced holes just outside the outline.  Then used the dremel with a cut off wheel to cut between the drill holes.  Then put a sanding drum in the drill press and sanded to the template line.  Took about 15 minutes to cut it out and have a finished blank in my hand ready for foiling.  Foiled it using a combination of sanding drums, a sharp flat file and my sander.  Obviously I’d get a scroll saw if I was going to do more than the occasional fin but what I did worked perfectly for a one off.


thanks for all the input. I think I’m going to mess around with some epoxy putty and see if I can make something for with this fin. just as a quick 'n dirty experiment. At least that way I won’t spend hours on this thing only to be bummed out when it fails.

Then I will probably create my own molded base for the waveset box, if I can’t find a more affordably priced original or reproduction waveset fin by then. 

awesome input thanks everyone. 

I doubt you will get the epoxy putty to bond to lexan.  There are several hits on ‘Bonding Polycarbonate’ on google.  But once again I don;t know how well it would work, nor the final costs of the products.



If it were mine, and I was trying to retain the full value of the original board, I might just take that green FU base fin and build up the base with more layers of cloth to reach the thickness of the wave set fin, then grind it to the shape of the waveset base.


Good luck, let us know how you make out.

Fit the fiberglass fin in the old box base and all fill the rest of the box with Bondo glass a couple glass football patchs over box and fin base for strength and ride it. If you just want to ride it not restore it,


Some where in my garage I have a WAVE SET fin box with an adapter for a modern fin. I tried to find it so I could take a picture but you can never find stuff when you need it. What measurement is your fin from base to tip (height) ? Are you in Ca. ? 


Funny how those old waveset Hypo fins bust at the same place!

Went through the same thing years ago, actually found some new old fins from someone (I forget) big bucks!

Figured I’d make my own.

Photo 1. Don’t do this!  Could not sculpt a fin and foil from a massive chunk of glass. I gave up!

Photo 2 Bought a Yater fin for FU box, cut off my sculpted fin and used the base and new fin. Use to plastic base to rough in all the tapers etc. on the fiberglass base.

A lot of trouble but worth it! I think it would be easier to lay up the FU type with glass to make your own base sandwiching the fin between layers.

Photo 3 finally my spoon with a spoon fin!

let me know I’d love to take that off your hands. I’m in Hermosa beach. The greenough fin I have is 8.5" and the waveset fin I have was probably 8.5 or 9" before it broke. Now it’s a bout 6". thanks. 

The first 3 fins have been modified. First fin on the right (black) is 7 3/4". Middle fin is 5 1/4". Fin on the left is 6 1/2" which appears to be similar to yours and probably broke the same way. The fin in the back is 9 3/4". Which one do you need ? I’m over in San Pedro.

mickey - I sent you a private message regarding this. definitely interested in coming by. I sent you my contact info in the private message. thanks!