Hi all, by popular request here's some info on my method for converting an old twintip to foilboard. This is the second board I've made for foiling, the first being the 114x46cm beast in this thread - www.seabreeze.com.au/forums/Kitesurfing/Foiling/New-minimalist-home-built-foilboard?page=1

The second board is a 2012 naish momentum, 136x43. Here are the steps:

Cut 12cm off the tail - seal with epoxy.
Drill oversize holes for foil mount and fill with epoxy-microballoon mix (rear holes 12cm from tail).
Sand base and fill channels with epoxy-microballoon mix.
Two tapered and angle offset bits of unidirectional carbon on the base, starting behind the rear mount holes and going as far forward as my front foot.
Two staggered bits of uni-carbon on the deck, again only from the rear mount holes to an estimated front foot position.
Fill coat of epoxy-microballoon mix for the underside, including building up a few mm thick where the mast will sit.
Sand the mast mount area flat.
Drill out mounting holes - 10mm (having marked them earlier so you know where to drill.
Drill satellite 3mm holes for the teeth of the m8 T-nuts to sit in (the oversize original holes are large enough that the satellite holes are still within the filler, so no wood exposed ever.
With a tiny bit of epoxy, set the T-nuts into the holes. Then, being certain that no resin has gotten onto the internal thread of the T-nut, screw a mounting bolt in from the underside, with a few washers on, and tighten moderately. This pulls the T-nut down and seats it firmly on the topside of the board.
As in pics I use countersunk bolts sitting in oversize washers. This lets the angle of the bolt conform to the t-nut, rather than fight it in the case that the t-nut and bottom mounting surface aren't perfectly parallel.
Paint the bottom of the board if you want.
Put some sort of deck grip on the top. (I didn't use a filler on the top laminate as it is all covered by the deckpad.
Ride.

This board handles very similarly to my made from scratch shorter and slightly wider board. Despite much chatter to the contrary they both get going with a similar amount of power and both handle touchdowns very similarly. The only noticeable difference is that on the twintip board, due to rocker between the foil mount and my front foot, my front foot is both slightly higher, and slightly angled back. This is perhaps an advantage when dropping down larger swells, but really I simply get used to whichever board I'm on.

The twintip board took less time and materials to make than the original pawlonia board. The naish worked well because there is no shaping on the topside of this model, so the standing area is all flat.

I'm going to make a smaller (100 x 43cm) pawlonia board with a variation on my original kerfing technique, and ride the twintip board in the meantime, so the original is up for sale if anyone wants a small, light, tough, simple board.

Any questions, hit me up.