I will be ready to do my cowl shortly. I had planned on doing it via the "Lost Foam" method with finishing resin and 2 oz glass cloth (3 layers). I have been hearing about all the "good" stuff from using water based polyurethane on 3/4 oz cloth for wings - will that work with 3 layers of 2 oz cloth over a foam mold for use as a cowl ? I plan on using a 2 stroke 61 and the engine will be totally enclosed in the cowl, includding the muffler (I will have to cut for air flow and for heat release).

Is this a good idea ? Has anyone ever done a cowl this way ? If it is a good idea (for strength and rigidity) will using gasoline to remove the foam damage the cowl ?

Thanks