im trying to make a plexiglass longboard skateboard out of plexiglass
I would recommend using a polycarbonate like Lexan or Hyzod instead of acrylic resin products like Plexiglas. They are considerably stronger, yet easier to work with. I think a 3/4 inch thickness would be lots if you went with Lexan, but at 4 feet long, any plastic sheet is going to be bouncy (Plexi will snap). You might have to edge it with something rigid to fix that. Usually anything over 1/4 inch (~6mm) is special order, but you never know, a local sign shop or glass shop might have some cutoff for you.
Well, since it is 4 feet long I would build in a saftey factor and go with around 2-2.5 inches thick
