(I think this has been answered before, but I can't find it. )

My foil's tuttle head is loose in the box (wobbles laterally). I think I've read that a solution is to add some epoxy with q-cell (or carbon scraps?) to the box, coat the tuttle head with grease/wax and jam it in there. After it cures (and if you can get the foil out), it should be a perfect it.

Seems simple at first, but I just know I'll end up with the foil permanently attached to the board. I saw one post (www.seabreeze.com.au/forums/Windsurfing/Foiling/Fin-box-repair-) about using straws in the screw holes but that process was about injecting it in from the top. (Also, where do you get proper straws these days?)
If I'm filling the entire box, what about the barrel nut holes? How do you seal those up? And, my tuttle head has all sorts of scratches and imperfections. Seems like that would be a great place for epoxy to get into to make a mechanical bond. I guess I should fair the head super smooth first? And, how much of the box should I fill up with thickened epoxy? All the way to the top (as above) or just enough to tighten up the walls?

Any other tips or advice for this?

I probably depends a lot on just how loose it is but there are easier solutions if the problem isn't too severe. If you can figure out where the Tuttle head isn't fitting tightly you can just add a layer of epoxy putty to those areas on the head (not in the box) and let it cure. Then sand it smooth and try the fit. If it won't install at all sand a little more. If it's still loose add another layer and try again. If it's tight but easy to insert add another thin layer and sand that out etc until it needs some real wiggling to get it all the way settled.

You can use two-part epoxy with microballoon filler or ready-made gap-filling epoxy. In USA good products are JBWeld, Marine-Tex and PC-11. JBWeld in particular is insanely durable, although none these products is as incompressible as the Carbon or Aluminum of the original head, so you may need repeat treatments.

just put a single layer of a thick 'all weather tape' on the foil head

Instead of tape better cut a beer can to a sheet and try out if one layer helps. I saw a lot people doing this at foil race events in silvaplana

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PatK said..
Instead of tape better cut a beer can to a sheet and try out if one layer helps. I saw a lot people doing this at foil race events in silvaplana

"Foil's still loose. Open me up another one, barkeep."

When you say "laterally" I assume you mean left and right, not fore and aft. The tuttle design calls for parallel left and right side walls. If you are getting wobble left and right, the first thing I would suspect is a cracked finbox in the board. Shimming the sides of the tuttle head just opens the cracks more, and you get water ingression. Big problem.

If, instead, the wobble is fore and aft, it clearly means that the tuttle head is not completely seated on the fore and aft rounded tapers.

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segler said..
When you say "laterally" I assume you mean left and right, not fore and aft. The tuttle design calls for parallel left and right side walls. If you are getting wobble left and right, the first thing I would suspect is a cracked finbox in the board. Shimming the sides of the tuttle head just opens the cracks more, and you get water ingression. Big problem.

If, instead, the wobble is fore and aft, it clearly means that the tuttle head is not completely seated on the fore and aft rounded tapers.

Good point, and you'd definitely want clean up the box and shine a bright light in there to look for cracks. You'd also want try another Tuttle head in there to see if it's loose also which would be a big red flag. But a fair amount of the time it'll just be friction wear. On Slingshots for instance the black anodizing will wear off and the foil will be little easier to slide in which puts more load on the flange.

I had white lines fore and aft in the box, they were not cracks but corrosion between the box and carbon head, so I sealed them with epoxy and no more corrosion. Had to do the same on the outside of the box where it met the mast head flange which was made of carbon. So do not assume any whitish lines are cracks in the box.