How would you reinforce a existing Deep Tuttle box in situ to take the load of a foil?
Thinking not to worry about the sides of the box and just reinforcing the deck and bottom
with a few layers of glass to spread the load.
My foil has a big flange which sits up against the bottom of the board
and I'll make a spacer between the top of the tuttle head and the bottom of the deck
You reckon this should be enough?

Have no idea if this will help but one of the guys I sail with has an Exocet slalom board which he uses a NP ally foil with.
He cut out a piece of nylon from a kitchen cutting board approx 15cm x 10cm and uses this on the deck to spread the load.
The board has a normal deep tuttle box, no reinforcing. He has been using it all summer with some horrendous crashes and its till going strong.

Use it like that, the flange should be enought by itself
then if it eventually breaks it'll be time to fix it then

Big guys or strong guys might consider adding woodies around the box, bigger flange on the bottom, top flange, new high quality fin screws, couple additional glass layers on the bottom around the box, and fully seat the flanges.

Slingshot comes with a gland as part of their mast.
www.seabreeze.com.au/forums/Windsurfing/General/My-First-Time-on-a-Slingshot-Hydrofoil

Although at the National windfoiling championship a lot of the racers were keen to change the angle the foil mast fitted into the box. A few degrees changed foil control dramatically, having an adjustable flange could be helpful in this situation.

Seems like it might be a good idea to embrace the idea of something like the Manta foil ad on and bolt on flange for foiling with normal boards.
I

I have an old Tabou Manta 79 slalom board which I have converted to a foil board. The Tabou is 79cm wide and 125 litres which is plenty big enough for me at 75kgs. I like the deep concaves in the nose which helps with the touchdowns when foiling. The deep tuttle box goes all the way through to the underside of the deck . I decided that only the deck area around the two bolt holes and under the rear straps needed to be reinforced. I used about three layers of carbon cloth and many layers of 50mm wide carbon tape to tie everything together. The footstrap screws also help to spread the load through the board. I made a timber block to go under the bolts to spread the load. With the foil I understand the main force to be upwards at the front (and hence downward on the aft bolt) - unless of course if you hit something and then everything will be opposite. Either way the extra load should be well spread by the new carbon layers. The bottom of the tuttle box was also filled so that the top of the NP foil touches the box - stops the foil from being pushed too far into the box and splitting it. It was an easy job and the bottom of the board remains original so that I can still use it as a slalom board. Cost was about $100 so I think well worth the effort. Only used a couple of times so far with no problems. The board foils in under 12 knots with a 7sqm no cam sail.

I would like to show some photos but the "My Photos" tab does not seem to work. It just puts a photo over my words so that I lose the lot!
I will try adding photos to Seabreeze photo section and copy from there.

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