try the rice-paper
Hmm… I’m not sure if rice paper tightens up and conforms like tissue paper but this seems like it would be worth a shot.
I’ve tried looking and asking around for the “micro sandwich foam” that wyve mentioned but I haven’t found anything yet. If anyone has any idea what that is please let me know.
I think small fractures led it to leak as after a session the board was half full of water
I suppose we shall see but I have hope based on my testing so far and the fact that wyve surfboards seems to be able to make lattice boards work somehow.
I’ve been doing some strength testing on the voids today with the different layups. I also put a hot coat on each test piece yesterday to give it some extra rigidity. Even 1 4oz layer does seem to be able to take my weight when I put my full 185lbs on my heel down into the void although 1 layer of 4oz cloth has much more flex than 2 layers of 6oz as would be expected. Then I tried pushing a large #3 phillips screwdriver through the voids. The results of that were:
1 layer 4oz - could do it with one hand with a decent amount of force
2 layers of 4oz - could do it with one hand and slightly more force
1 layer 4oz, 1 layer 6oz - could not do it with one hand, took lots of force with two hands
2 layers of 6oz - same as previous, could not do it with one hand and took lots of force with two hands.
Its not very scientific but anecdotally based on flex amount and puncture avoidance I think 4 oz on its own (even two layers) is just too soft for the size of my voids. 1 layer of 4oz and 1 layer of 6oz is probably the minimum I’d want to use so that’s probably what I’ll do for most of the board and then maybe I’ll add an extra patch on the footbed area to give some more strength there.
One other thing to note… on Make Cardboard Surfboards
Sheldrake recommends 1 layer of 4oz and 1 layer of 6oz on their smaller boards and then an added layer of 4oz on the top. This gives me some level of confidence that I’m in the ballpark here for my layup if that’s what the cardboard guys are doing.
Glues… I tried many different glues to stick the tissue to the plastic with varying levels of success. The winner needs to soak into the paper so that it can follow the shape of the board and also stick well to plastic:
White Glue - conforms well but isn’t the strongest hold
Wood Glue - conforms well but isn’t the strongest hold
Glue stick - doesn’t conform well or stick well
Lepage Spray Adhesive - sticks pretty good but extremely messy and takes a long time to dry under tissue
CA Glue - sticks very well but causes wrinkles in tissue and doesn’t allow tissue to conform
epoxy - doesn’t soak into tissue easily to conform to board shape
Water Based Varathane - Conforms well, sticks pretty well, yellow tint
Water Based Concrete Sealer - Conforms well, sticks pretty well, clear finish. WINNER
I also wanted to try the actual dope used on balsa planes but I don’t have any and the internet says it doesn’t work well on plastic, could melt it, and has terrible fumes so I think I’m ok with not testing it and I’ll just go with the clear water based sealer I have.
Once the tissue is attached to the board I can then either a) coat it with more sealer to strengthen it b) coat it with epoxy as stoneburner suggested or c) just start doing my layup right on the bare tissue. I did a test piece to see if c was possible and it seems to have worked perfectly fine with the thicker 17gsm tissue I’m using now and it still resulted in a perfectly flat surface so I think I’ll go with this method to save a bit of weight unless anyone sees a good reason not to. I’m doing a final test piece with this method now to confirm everything and if all goes well I’ll go print another board and hope for the best.
I read somewhere that wyve make some kind of molds for the glassing process