wrote:
Tank is also parellelogram in plan, i.e. any reasonably avail polymer
tank which may fit the space will be of lower capacity.

Not necessarily. Assuming that you're in the US, check Ronco Plastics
(http://www.ronco-plastics.com)...they have more than 400 stock molds,
over 100 of which are non-recectangular.

Tank has a
small lkg IWO a vent o-let,

A what????

but R/R time window is short (5 days).

Hey...lack of planning on his part doesn't necessarily create an
emergency on anyone else's part!

Al tank will be
pried out of its foamed-in place position via the usual Chinese
firedrill that requires in AM, & taken ashore.
We are contemplating
the *option* of cleaning the tank, assessing its condition...

A waste of time...'cuz if it's leaking anywhere, what you're gonna find
is a tank that's a about to spring a bunch more leaks.

and if not
significantly wasted, welding and/or doubling the leak, blasting or
otherwise prepping it's insides, and coating it with an appropriate
epoxy or other suitable coating in order to exend its service.

Not worth the effort.

My advice: Slap some Marine Tex on the existing leak--it won't hold
permanently, but it will for a few weeks--to get through the impending
"emergency"...then take the time to find a fit a replacement tank. 'Cuz
to do it right is gonna require new hoses and at least some
investigation into plumbing mods.

Plan B: Go ahead and pull the tank out--but if you do, just take it
straight to the dumpster. Put a portapotty onboard to keep him legal
till he can take the time to do it right...'cuz there's a lot of truth
in old adage, "do it right the first time, or expect to do it over."

--
Peggie
----------
Peggie Hall
Specializing in marine sanitation since 1987
Author "Get Rid of Boat Odors - A Guide To Marine Sanitation Systems and
Other Sources of Aggravation and Odor"
http://www.seaworthy.com/store/custo...40&cat=6&page=