Making a holding tank to fit the curved hull space

[Don C L]

Has any of this got you thinking of a Nature's Head or an oak bucket yet?

As for the extra space, if there is room and it doesn't cause a problem, you might store extra chain down in there.

[Bowdrie]

Originally Posted by Don C L

Has any of this got you thinking of a Nature's Head or an oak bucket yet?

A good bucket has lots of uses, even one made from Mahogany.

[thinwater]

Integral tank. That is what my last boat had, and it was great. Best way to make a strong, impermeable tank.



I would add some glass to the hull and a resin-rich inner coat; you want it smooth and impermeable. Also, the tank ends now serve as bulkheads, so they need to be gusseted accordingly.



I would not use ply. I would use ~ 1/4" precast structural fiberglass (like G-10 but less expensive and more than good enough). More permeation resistance. Fillet and tape it in, and then add a thin glass veil to reinforce the liner resistance.

[wingssail]

Good project, interesting. Yes, shape to fit the hull curves.

I did a similar holding tank. I laminated flat panels (my space was not curved) and cut them for all the sides of the tank then tabbed it all together.

My mistake, and you should try hard to avoid this one, is that the tabbing on the corners was not sufficiently strong and the tank broke! (twice!). Not fun. This happened when we had filled the tank with fresh water from the deck pump out, which is nearly 5 ft of head. Big bang and the tank emptied into the bilge (now I have a stainless steel tank.

So make it strong.

[rslifkin]

Agreed on the make it strong part. As I'm working on my integral water tank I'm not trying to optimize the build, but instead going for what is guaranteed to be more than strong enough.