Dry method is good when working on horizontal surface like a deck. Set fiberglass on its place and start spreading epoxy over it. As the fabric is wet out it will become transparent, indicating the cloth has absorbed enough epoxy. A plastic squeegee is handy for spreading epoxy. Setting fiberglass on right place is easy.
Wet system works for vertical and overhead places.
Wet the surface with epoxy before applying fiberglass, and follow the same steps as the dry method. The difference in the wet method is that once the fiberglass has been put down on the wet surface, it s hard to move around.