[SteveCox]

I'm getting ready to build some new tanks (and I know all about epoxy and potable water, that's not the issue here ). What I'm wondering about is whether I could use styrofoam as a core material rather than plywood or building out of solid fiberglass. It certainly would be easier to shape and once laminated on both sides be very rigid. It would get away from the issue of core rot which can happen with ply. Thoughts anyone?

 

[sailingdog]

Yes, you can use styrofoam. Do be aware that polyester and vinylester resins will DISSOLVE styrofoam, due to the styrene in them.

However, IMHO, you'd be better off using one of the PVC-based foams—Airex or Divinylcell. They're just as easy to work with but will give you greater strength in the finished product.The problem with styrofoam is that it is structurally much weaker than either Divinylcell or Airex.

 

[timebandit]

Works for surf boards.