I prefer 2 part resins as opposed to water based urethane for applying cloth. They are much harder and stronger and the urethane would not give the structural addition required when ommitting center braces in a foam wing. We have had good results from West Systems Marine epoxy,as well as polyester resin. Both mix up thin and dont tend to build up when applied. We apply the cloth with 4in. foam trim rollers. Let the cloth extend around the edge about 2 inches,when the resin dries,just sand off the excess with 180 paper.