pvc? hmmm so why bother fibreglassing?its not needed!!theres a reason its made lite you know.the heavier you make it the more motor you will need to power it.you dont need to fibreglass it its not a race boat have a look at this one i built my son its all balsa and just epoxy coated and its lite and strong .its a higgins boat pt 305 to be exact i made everyting on the boat guns torps its not quite finnished yet but she looks good i think.[link]http://www.youtube.com/my_videos[/link]