I got down to Fangy's today only to discover that my fin didn't fit the box. Fin box too large, so I thought I'd share my way of rectifying the problem. Had three different grades of wet n dry, 220, 600, and 1500 wiped down with wax. I'll explain the wax later.
Knowing that it's the front and rear angles that hold the fin in place, that's where to start.
After setting things up with some soft jaws, I removed a small amount of material with the 220 by using a seesaw motion, then cleaned it up a fraction with the 600. Then finished the process with the wax infused 1500. This gave me a very smooth surface to work with as you can see in photo no 2. I then put the fin in the box and tightened it up.

This left me with an indication, caused by friction, which you may see in the 3'rd photo, of exactly where the material needed to be removed. After that it was just a matter of remove material, fit, and repeat. I removed 1mm and the box sunk down 2mm making a snug fit.

Hopefully this will help anyone with the same issue. Taking it easy will ensure that you won't remove too much material.

OMG , I thought you had a problem with a Fangy fin .

Beautiful Pepe. Always the craftsman.

Didn't cavemen invent fire that way ?

Good tip with the wax. What is the purpose of the out-of-date green waste voucher ?

Select to expand quote

jn1 said..
Good tip with the wax. What is the purpose of the out-of-date green waste voucher ?

That's a reminder that we have to have a romantic trip to the recycle joint to dispose of the build up of crap that clutters the yard, just to save the marriage
It's kinda like, there's no need to remind me every 6 months, I'm on to it, ok.

As it was centred in photo, I thought it was an integral part of the fin fitting process. Well, at least I won't die wondering now

Select to expand quote

jn1 said..
As it was centred in photo, I thought it was an integral part of the fin fitting process. Well, at least I won't die wondering now

An unintended movement of crap on the workbench. Got every bit of stuff from the cnc machine on the bench as I've just replaced the spoilboard.

In order to avoid confusion, I recommend terminology. The "box" is what is in the board. You were sanding the top fitting, not the box.

Select to expand quote

segler said..
In order to avoid confusion, I recommend terminology. The "box" is what is in the board. You were sanding the top fitting, not the box.

The fin head

Select to expand quote

segler said..
In order to avoid confusion, I recommend terminology. The "box" is what is in the board. You were sanding the top fitting, not the box.

With those three pics , I was not confused .
And I confuse easily.

Still bugs me that board and fin makers can't make stuff the spec so all fins fit in there boxes without either having to build them up or sand them down. What makes it worse is if you use the same fin in different boards then you have to decide which one you ant it to fit right in

Select to expand quote

Ben1973 said..
Still bugs me that board and fin makers can't make stuff the spec so all fins fit in there boxes without either having to build them upTuttle_original_specification.pdf (mikeslab.com) or sand them down. What makes it worse is if you use the same fin in different boards then you have to decide which one you ant it to fit right in

Yeah, I had this problem, so I decided to look up the specs to work out which was out of spec. And I found Larry's drawings here
www.mikeslab.com/Tuttle_original_specification.pdf . I love my digital vernier calipers.

If read that right, then a fin can easily stick out more than 1 mm with both the box and the fin-head within their specs...

Select to expand quote

MikeyS said..

Ben1973 said..
Still bugs me that board and fin makers can't make stuff the spec so all fins fit in there boxes without either having to build them upTuttle_original_specification.pdf (mikeslab.com) or sand them down. What makes it worse is if you use the same fin in different boards then you have to decide which one you ant it to fit right in

Yeah, I had this problem, so I decided to look up the specs to work out which was out of spec. And I found Larry's drawings here
www.mikeslab.com/Tuttle_original_specification.pdf . I love my digital vernier calipers.

I love my non digital vernier calipers. The batteries never go flat.

Back in formula days when we were all using deep tuttle fins, this issue always came up.

People like Sailworks always advised that sanding is the LAST resort. First use lube to fit it into the box. This usually works.

Sure, you can definitely sand off any burrs or high spots, but be VERY wary of sanding the main surfaces. Too often people have sanded the main surfaces, then found that after a few insertions and sessions, they had sanded too much. Happened all the time.

Yes, the sides of the Formula fin heads can certainly be like that, it is easy to take off too much material, as they "wear in" with time. The front and back are a little different though, I actually make mine a little curved there so that I can tune on the angle a little (more or less upright) and then simply tighten in the desired position.

Another tip that didn't come up (or I missed it) is too use bar soap on the fin head. After tightening and removing, the high spots will now be shiny, and then you know where to remove material.

Making the front and back rounded tapers a little curved is an idea I have not yet seen anybody mention.

Good idea. So that, when you mount and adjust rake, the contact inside the box is spread out a little more than just a sharp area. A sharp area creates a stress riser that can damage the box. Spreading it out, even a little bit, is a great idea.

Fin yea ok, sanding etc eh no but your beautiful traditional wood workers bench with end vice ,,,,,want!