KR Netters: I have bee perplexed for som time on how to make a 3-gallon header tank but I think I have a solution that uses the pre-molded F/G tank for a mold.
Simply use PVC Foam Bead-Board to fabricate dams in the pre-molded tank in accord with the volume desired and line the cavity with saran-wrap for a release agent. Then place a piece of plastic pipe in the middle of the cavity equally spaced from the foam dams and any side wall of the pre-molded tank. In the middle of the volume outside the pipes hang several very light chains(optional). Then fill the void contining the chains with "Casting Plaster" of "Plaster of Paris". When it is cured then remove the pipe in the middle and the plaster cast from the pre-molded tank. You should now had a form to lay up your header tank on. After your tank is cured then wind the chains up that you cast into the plaster on a slotted flat bar to break up the plaster form and free your new tank. I got this idea from the way filament winding forms are made for limited production cylindrical tanks. Don Lively Burlington IA 52601
