Sounds like a brand of margarine. No I still haven’t shaped a blank yet, but I am ready. Nothing more to do but run the router over them. I have the router bit (I got a better deal at the local tool retailer, 20% cheaper than Bunning’s across the road, only $34 so not too painful given I wont be able to use it with my router!) and I have glued the cedar sheave blocks in, I did that today and need them to set overnight. All is now ready to shape the blanks. My next entry here (tomorrow night hopefully) will be to report on how the shaping went. I have not cut the slot down the centre of the trailing edge or glued the batten in, deciding instead to do that after I have shaped the blank. This is somewhat more difficult given I have to cut a slot on the trailing edge that will then be only 10mm wide but the foam is quite easy to cut by hand so I think I will not have too much trouble cutting the slot and I will not have to worry about it not being in the centre of the blank as I shape it as it will be very easy to centre cut it after the blank is shaped.
So today I finished the jig by attaching the female moulds permanently into the jig with backs on the outside set to the centreline as another line of measure to ensure both sides are exactly lined up, they also ensure the blanks sit in exactly the same place along the jig (left to right) and cannot move either left or right. Tomorrow when I replace the blanks in the jig with the male plugs on the ends they auto seat themselves in the correct position on each side, and all I need to do is run a couple of screws through the end plates into the male moulds to stop the blanks moving and all is ready to shape.
Then I cut some cedar off the planks I have and trimmed them down on the table saw to the width of the blank (65mm a little oversize to be shaped down) then on the mitre saw to 200mm as the plans call for (100mm either side of the pulley centreline). 4 of them, 2 in each blank. Then it was a simple matter to cut the foam out to glue the cedar in its place. A jigsaw is all you need. You can start the cut by drilling a hole if you like but it is easy to just start the jigsaw on an angle and straighten it down then cut as normal. I cut a little undersize then trim out to a snug fit. Then just paste it up with glue and wipe back the excess and push some into any loose areas not full. Once set tomorrow the cedar will shape the same as the foam.
Once shaped there will still be a need to fair off the corners created by the router cutting like a Christmas tree, a series of steps, not unlike what I have now but much smaller and closer together. I may try to angle the router to cut parallel to the required shape to minimise the fairing but foam is very easy to sand so there is no great need to do this. Then once the blanks are faired the next step (after gluing in the batten) will be to glass the blanks.