I am rehab'ing a 1973 twin I/O 34 ft Nauta Line houseboat and want to install a holding tank. There is no room above the floor I would give up to put in a tank. I would like to put a tank in on the opposite side of the keel under the floor where the water tank is. The tank needs to be flat on top, vee shaped on the bottom, about 16 in wide 6 in on short side 7 1/2 in on tall side and hold about 40-50 gal. I would like plastic tank, I don't think aluminium would last long. Anyone know of any manufacturer's, or has anyone build a custom tank of fiberglass- if so how did it hold up?? any help appreciated.

This will fall under the topyc of "wish I'd kept that URL". Yes there is a place that makes custom plastic tanks. I erased the addy from my list though. Search with MSN search engine, that's how I found it.
Sewer gas will permiate most materials. making for a very smelly boat. Choose very carefully what the holding tank is made from and how it's vented. The ideal locarion is under a outside deck if possible.

RONCO PLASTICS MAKES ALL SHAPES AND SIZES.

TRY TO KEEP IT IN CEBTER OF BOAT TO PREVENT LISTING.


http://www.ronco-plastics.com/

I installed a fexible holding tank in a very similar boat as yours. It was installed under the booth seating located next to the head wall. This made plumbing a short run and simple.

The vent hose was installed where the seating meets the outside wall and vent was installed under the walkway, while the pumpout/fill cap was routed above the walkway and installed in the outside wall just fwd of the dining table window using 1 1/4 vinyl holding tank hose. Operator reported no smelly problems and was very pleased. capt tom.

Thanks for the help and good leads. I think I have a solution!