Alex wrote:



What about making the core out of Styrofoam plastic, wrapped in release or
heavily waxed, and after the expoxy sets up dissolving the Styrofoam with
gasoline, acetone, MEK or some other solvent that attacks the foam but won't
hurt the epoxy?

A possible advantage of this approach is that it allows the production of
shaped epoxy parts that are more complex than a simple tube, should that be
needed.

Epoxy is fairly resistant to gasoline and many other common solvents, but it
certainly would make sense to "insulate" it from the solvent with the
release sheeting, heavy wax, etc., and then to thoroughly clean it after the
core is removed.


I've done this one several times.
It works quirw well.

Downside - the inside surface is goinf to be pretty rough - resin
seeping into the crevices in the foam.

If that is not a problem (and in this case it's probably not) this
is probably a reasonable approach.

But if I had to make this part?

I'd use a paper tube for the core mold.
Just make sure it's not waxed paper...

Richard