Crooked F/U box

I installed a fin box into the tail of a pintail and foolishly ‘routed’ the slot with a dremel tool. Of course, my box came out crooked even though I took pains to measure and what not. As a result, the fin is ‘toed’ in toward the right side rail at about 4 degrees from the stringer. (this was my first FU box install).

The board was originally a thruster set up with FCS. I was bored with it and decided to convert it into a mandala type California pintail single fin- hence the box.

Any predictions on how this will impact the way it surfs? (We haven’t had any appropriate surf for me to test it this week.) Dims on the board are 6’6’’ by 18 3/4 wide by 2 inches thick. I was planning on using this in good quality surf in the head + range (if we ever get any again).

Also, does anyone have any suggests for getting the fin properly aligned short of ripping out the box and trying again? I was considering altering the slot some and then making the fin permanent. Thanks in advance for any thoughts and predictions.

Fin boxes are not that hard to pop out and cost less than $10. I think the only way to be happy with it is to take the crooked one out and re-install otherwise you’ll end up with a screwed up fin that may or may not work.

There are several posts on how to do this, but here’s my version. I take a skil saw set just to the depth of the box and carefully cut a slice in the bottom of the fin slot. Then with a dremel or router cut through each end of the box. Now start on one side with a big screw driver and knock the side toward the middle. The box side will generally pop loose pretty easily and you can work it out. Repeat on other side and then clean the hole up with a router.

ride it first

it has in the past proven to be ok.

if it is not you will know right away.

replace it then.

a good board is a good board is a good board…


good luck…

my last board the box went in a few degrees off center. I don’t think it’s as drastic as 4, not that that’s all that drastic anyway. I could tell no difference at all. granted I never rode the board with the finbox dead straight either, but the board rode great and could never tell that it had a problem.

Do waht ambrose said.


Just go ride it. The only thing you MIGHT notice is that you will stand about an inch closer to the toe-in side of the board than otherwise. As a single fin all that happens is that the fin and board redefine the centerline of travel .

Thank you for your responses everyone. I guess I’ll just ride it!

Looks like I’m in the minority here, but maybe that’s just my windsurfing background coming through.

Just out of curiosity, how many inches (or more like fractions of an inch) do you mean by 4 degrees off center?

Whatever your decision, looks like it may be a while before we get any good surf to try it in.

Using a jig will save you this heartache next time. If something is going to be set in stone (or concrete or epoxy or resin) I live by this rule. Seems to me a jig is nearly always worth the time it takes to build the thing.

But that’s just my 2c. Your mileage may vary.


I go with the group consensus, ride it first then decide. Ride it a couple of sessions to be sure you need to correct anything. If surgery is required, cut it in half as mentioned above with a Skilsaw,router, dremel or whatever. Next step, I’ve had luck in heating the plastic up by running a router with a straight bit around the inside slot. As the bit thins it down it will also soften and weaken the bond of the resin holding it in. Once you heat it up the bottom and side laminate will release easier as you pry it out of the hole carefully. Good luck.


I’ve gathered some data and am ready to report. As far as the precision of my 4 degree estimate… that has the rough equivalent of saying… it is a smidge off (or maybe slightly wonky for the wozzies out there). Most of my friends who look say: “eh, it doesn’t look too off.”

I took it out in some mushy knee to thigh crap on Friday afternoon just to see. The occassional waist high bomb was most enlightening. The board went well going left (backside for me and with the fin biased in toward the wave face). No noticeable hum or other symptoms.) I noticed a slight tremor/hum once or twice while going right but all in all was pretty satisfied. Of course, the waves weren’t a great test track for this board–would’ve been super fun on a fish though (in an all things are relative east coast sort of way.) As soon as we get a noreaster with some size I’ll collect some more samples. Thanks for all the comments and suggestions. I’m not going to take any drastic action just yet.

Native: Is there an NC swayloholics anonymous or the like? If not, it seems like that might be fun.


That fin would get inside my head. There’s no way I could evaluate it objectively. Loan it to a friend that does not know about the box and let him evaluate it. I’d probably fix it or sell it for cost of materials and build another. Mike

 Howzit native, A few years back a friend got a board from a really well known Shaper/Surfer and loved the way it rode. Well one day I'm looking at the board and notice that the fin is not exactly perpen dicular to the bottm so I checked it and it was a 1/2 " off from the base to the tip. The guy couldn't believe it was so bad yet the board rode so good. Then it's gets into his head and he sells the board. So I'm down at Pine Trees one day and see the board on top of a car, I walk over and ask the guy how he likes the board and he says it rides really great,never told him about the fin. Just goes to show that some mistakes really don't hurt the way a board works.Aloha,Kokua


I have a 7’6" funshape single fin and the fin is slightly canted toward the right rail. Maybe 1/8". You can see it if you look for it but otherwise it’s barely noticeable. A friend pointed it out to me so I told him to go ride it. He loved the board and couldn’t feel anything odd about it. I’m probably the most sensitive to my shapes and I can’t feel anything odd about it either. Chances are your board will work just fine.

If it aint broke…don’t fix it!!!