I took three days off work last week, as my trusty off-sider (aka dad) was in town to assist with the construction of 2 foils. My mould manufacturer (aka my brother Andrew), has done a superb job to produce a 3 piece mould, using the techniques I discussed here way back in July 2005.

The main changes since July were that due to concern around the strength of the T-join, we decided to make the foils in one piece, and not have to join them together. In addition I decided, at the suggestion of Andrew Stevenson, to add 2, L shaped 3mm stainless steel plates.

Another change is that Andrew added some aluminium strips to the mould, to remove the need to cut the slot in the foil when we were finished moulding.

Making these types of foils is like making stir fry, i.e. most of the effort is in the preparation, cutting everything to shape. We laid it all out on our cloth table, as you can see in these two shots. The second shot shows the balsa core that we glued the plastic tube to for the control rod. For the tube, we used 4mm irrigation upright tube, purchased from Bunnings hardware.

With everything prepared we moved onto the lay-up, starting with a layer of s-glass to make finishing easier, we used about 4 layers of 300gsm carbon uni, then some kevlar pieces, then 2 more layers of carbon, more kevlar, then the aluminium brackets, then along with some chopped strand mat and then the balsa core.

The author mixing some resin, and yes I know my gloves don’t match.







Adding some bog, prior to installing the bracket. Care was taken to ensure that there was no direct carbon to stainless contact.

So after the layup was completed, a ton of bog was added and then the two halves were bolted together. The hydrofoil section was then laid-up and added to the bottom of the mould. After curing for a day, the mould was then opened up and the dags removed from the foil.