In response to queries about using US Composite epoxy resins , I have just built a sailboat in my garage using the 635 resin and medium hardener. I highly recommend this material. I have built 3 CLC kayaks over the past year using MAS epoxy and I can find no difference between the 2 other than price. This system has not blushed and is about the same viscosity(thickness) as the MAS. I have also used West system and found US Composite about the same.
One mistake that some builders make is buying the slow hardener. This hardener will not set below 65 degrees. It will stay liquid until the temp. reaches that temperature. I buy the medium hardener and have worked it to temperatures in the 50 degrees. The cure time may take 24 hours instead of the stated 10 hrs.....but a 10 hour cure is at 80 degrees. Anyway ,I had a lot of success with this stuff and will continue to use it. Besides you can't beat the price.