NEO:

I use the West Marine resin. It is great stuff. The amount recommended by Darrell should be more than enough to do the SBD. I use 3/4 oz cloth on the fuse and 1 or 2 oz cloth on the wings. It is not that much heavier and it gives better hangar rash protection to the leading and trailing edges of your wing. If you wanted to use 3/4 oz cloth on the wing, you could add another layer of 3/4 oz cloth around the leading and trailing edges of the wing to give you some extra ding resistance. The seam sands out easily.

Another alternative to using resin is the Minwax water-based polyacrylic. I have read many post of others using this technique with great results. I tested it over the holidays on the elevators of a Tucano I am building and liked the results. It is much cheaper than resin and less messy and the results seemed to be equal. For this test I used 3/4 oz coth. On one elevator I used two coats of West Marine resin; first coat to adhere the cloth to adhere to the surface, second coat mixed with microballons to fill in the weave. On the other elevator I used the three coats of polyacrylic; first coat to adherer the cloth to the surface, second coat started to fill in the weave, third coat mixed with micro balloons to completely fill in the weave. Both elevators were wet sanded with 240 grit sand paper and the results were equal. I do not have a scale small enough to weigh the elevators to see if there was any difference in weight but they feel about the same. It took two days to get to get the end results with the resin and about 4 hours to get the results with the polyacrylic. I think I will be switching to this technique.