How to fix a shallow set bahne box? Single Fins Unlimited on Hayden Shapes Cannon

Hi Swaylocks - 

Long time listener, first time caller. :wink:

I recently purchased a used Hayden Shapes Cannon. I have not been able to find a fin that fits. I read a thread on here about hotcoating sometimes deforms the box slightly, and sanding the bottom of the fin base works, but in my situation, I think the fin peg will still cause the base to stick out. The seller says he’s unaware of the box being replaced. He also says he’ll sell me a fin that fits, but I’m hesitant to do any more business with the guy. I have since measured the depth of the box. Please see attached pictures. Was this box installed too shallow? Does it look like a bad fix, or might this be considered manufacturing defect & covered by Hayden’s warranty? Optimistically, I am hoping I can take it to Hayden, and they’ll say they’ll fix it. It doesn’t look repaired to me. Realistically, I bought it used, there’s a chance it was improperly repaired, or specifically custom ordered to be set shallow, but I can’t imagine why as the tail isn’t that thin & it’s more or less off-the-rack. ( 

I just want a sanity check that I’m not completely blanking on an easy solution before I take it to Hayden.

Also, should they likely tell me it’s my own problem (like the seller has), what’s my best solution? So far, my thoughts are:

(1) get the box replaced (I have no router to do it myself $$$$)

(2) customize a fin to fit $ (In the thread ‘’, @johnmellor wrote “No big deal.  A little ‘customization’ of the fin with a Dremel tool, file, and/or sandpaper and you’re good to go.” Would love to hear your thoughts/experience John. My biggest hesitation with this solution is reselling the board later. I couldn’t do it w/o full disclosure & I personally wouldn’t buy a board knowing it wouldn’t accept fins universally.

Any and all thoughts/advice are greatly appreciated.

Many thanks Swaylocks community


Judging by your photos, it appears that the fins will not set deep enough into the box. Seems simple to me. Grind/sand/cut the base of the fin so it fits. Don’t try to alter the box.

You may want to test drive a few fins on that board before you find the one that puts the grin on

so why not start off by calling Hayden, see what they say.

If not helpful, check with your local ding repair guy, probably $50 or so to replace the box, less then the price of a new glass fin.


Thanks SammyA. What about the metal pin? I’ve been looking for instructions on how to move the pin, but maybe it’s as simple as: (1) cut (2) drill (3) glass/glue in new pin? My biggest concern is cracking the fin while drilling, close enough to the original pin placement, but not too close.

Too much material missing off top side of box. Like you have stated, grinding base won’t help anything, unless pin location is raised.  I would talk to a fin manufacturer about buying a fin without the guide pin drilled. I would then take the measurements and just drill it myself. 

Thanks Icc. I agree, since I have yet to ride it, I’d like to be able to experiment with fins & be able to swap with friends. 

I know a picture doesn’t show much, but in your opinion, does the fin box look replaced to you? I’m planning to swing by Hayden with my fingers crossed (& hands out LOL)

Looks like a shallow install. Can you measure the tail thickness and see if it is thick enough to get a regular box to fit? If so then either route out the box and put another one in or have someone who can do it for you. If not then you might want to think about a glass on. Hope you got it for cheap. 

Hi Douglas - 

Do any of those fins ‘wobble’ from side-to-side when in the box?  There is probably enough of all of the tabs in the slot to work OK.

Good photos showing the same problem with all of the various fins.  I’d say the box likely ended up being installed too shallow and the top of the box was ground down flush with the bottom of the board.  There is a faint ‘ghosting’ effect around the box where it’s likely that either the original was glassed over (a good thing), or the original was replaced and glassed over.  If it was a replaced box, they did a decent enough job except for the depth issue.

I still think it would be easier to modify your choice of fin rather than replace the box.  I doubt that even if any of those fins were left ‘as-is’ that it would be that big of a problem.  

If you want to take a stab at it, a file or small disc grinder could be used to knock down the part of the screw tab that sits above the box.  Using the same tool, foil the part of the trailing edge so that any part of the fin above the box is smooth and matches the existing foil. Final clean up with some sandpaper.

Be careful about trying to redrill the pivot pin hole.  The pin placement has to be just right if you do it.  I’d guess that since all those fin bases are about the same height above the box, the pins are all likely in the right place.

I would be curious to see what the manufacturer says… it does appear to be a screw up somewhere along the line.  Either at the factory or by a repair guy after the fact. That ghosting effect around the box is hard to decipher from the photos.


Thanks phebus - I didn’t even think to order a fin w/o the pin. That would be easier & better than cutting the existing pin and drilling a second hole.

insanecutback - any “DIY” way of measuring thickness w/o calipers? Since it’s more or less an off-the-rack model & it’s got a bit of volume to it, my gut feeling is that the tail is not too thin for a standard box install. 

I thought I got the board for a fair deal, but this finbox problem has me rethinking that. 

Hi John - I’m really glad you saw my post!

Great tips on customizing a fin. Sanding down the top of the base would save me from redrilling the pin hole. 

Thanks also for asking, as I completely spaced on the fact that all the fins wobbled quite a bit. I was so excited when I got it I almost rode it even with the fin base protruding, but the wobble had be fearful I might crack the box.

If I do go the fin modification route, would you also recommend adding material to the sides of the base? Duct tape? Or is it not worth the risk of cracking the box?

The faint ‘ghosting’ effect has me concerned as well. I was hoping to capture that in the photos & I’m glad you commented on it. As long as it’s not an obvious sign of repair/replacement, I’ll have the guys at Hayden take a look and report back on what they say. 

Thanks John.

Hi - 

I’m not saying that the ghosting isn’t a sign of repair.  It may be.  It’s just hard to tell from this end looking at the pictures.  As mentioned, if repaired it appears to be solid and water tight.  I’ve seen lots of boards with factory fresh box installations with no glass over the top… not good in my opinion.

There are several ways to address the wobble.  I’d just slice a section of a plastic McDonald’s straw lengthwise and wrap it around the base before pivoting the fin back in to the slot.  After you play around with a couple of those fins you’ll have a better idea about which one is worth the trouble of modifying for a better fit.  

I don’t think it will hurt anything to ride the board with the fin sticking out a bit.  

On a friend’s bellyboard we sent a recycled (used) 15" fin box with the blank to the glasser.  They ground it down pretty thin and I modified his big Greenough ‘Paddle’ fin (also sitting proud) so the foil matched and the top of the base was flush.  It never seemed to matter that a fraction of an inch of the base wasn’t fully seated as originally designed.

The haze is from the weave of the glass showing from the patch job when the new box was installed.  You can see the weave in this picture.  This is an example of a bad re-do of a box repair/re-install.  This box has “floated” up during the install before the resin set, probably due to no taping and dummy fin installed until the resin set.  The bubbles sanded thru on the box are a dead give-away.  The mix was too hot and the box plastic expanded also leading to a sloppy fin fit.  There is a fair amount of white resin bordering the box.  When the box was sanded down, it was too shallow (and the patch glass exposed the weave, leading to the haze) for a standard fin and the repair guy sanded/modified a fin to fit or just sold the board to you…  Anybody who stands behind their work would not let something like this out of their shop.  I looked at the foil profile on the website and there is plenty of foam for a normal install this far up from the tail.  Pay the $$ to get it fixed right and you will be real happy with the board and be able to play fin swap and learn how important fins & fin position is!  Just my 2c…, to bad you are a continent away!

Right on surfteach.  I didn’t even notice those bubbles.  


it appears that you bought a used board with a crappy fin box replacement.  The original manufacturer is not likely to replace or repair it for you.  Why don’t you try to get your money back from the clown you bought it from?  Either that or take it to the nearest decent ding repair place and have them put in a new fin box the right way.

Post your location and maybe somebody here will be willing to help? 


@johnmellor - That board looks super fun and that water super glassy. I’ll remember the straw trick.

@surfteach - Thank you for taking an indepth look. I really appreciate your insite. I just checked my Merrick & Proctor, & the fin boxes on those boards fin boxes have bubbles as well. I know they’re not as high quality as most of the custom work displayed here, but I’m not so sure the bubbles are definitive of repair. What do you think? The glass weave & haze/ghosting probably are signs of repair. I won’t bother the guys at Hayden with this.

@keithmelville - The guy I bought it from told me to figure it out myself. I will be a more bewared buyer in the future, and will make sure to slot fins into boxes next time. At least he didn’t scam me out of my life savings? :-/ Hahah, fit shappens, silver lining and the funny side, inner peace. :-) This may be just the motivation I need to buy a router, and set to replacing the fin box myself. :smiley:

I’m in West Los Angeles; help replacing the box, welcomed. :slight_smile:

Thanks you Swaylocks community, all those who read my post, and especially those who commented. Wishing you all amazing, uncrowded waves for the Holidays.

I’m with John, ride the board with different fins, very likely you won’t notice any difference with a little bit of fin over the top of the box. Once you find the one you like the best, modify it to fit the box. If you can’t live with the box being low, then either you’ll have to pay $75 or so to have someone replace it, or you’ll do it yourself. Even if you do a perfect job, unless you like black plastic dust flying in your face, you’ll wish you’d paid someone to do it.

Conclusion: I ended up taking this board to a local shaper. He said it didn’t look like a repair was done and to call Hayden. He also told some stories of other “nice” boards he’d seen with odd SNAFUs. Understandably, Hayden said buying it 2nd hand voided the warranty. I’ve been riding it since as is w/o any problems. Thanks for all the advice swaylockians!