Godspeed wrote:
On Wed, 13 Jan 2010 12:26:39 -0600, dpb wrote:

Assuming you're in CA from the fire protection requirement, here's one
link that might be of some interest--they have black poly from roughly
the $2k range.
http://www.watertanks.com/contact.asp

I agree. The original estimate was wrong. The "poly" tanks appear to be
about $2,000 (plus California 10% sales tax).

From this link, there appear to be only 3 manufacturers (Norwesco, Inc. of
St. Bonifacius, Minnesota, Snyder Industries of Lincoln, Nebraska and RMI
in Gardena, California).
http://www.winebusiness.com/wbm/?go=...e&dataId=50707

They advertise a one to three year warranty for the poly tanks but say they
can last 15 years or more.

The tanks I have are welded painted steel, not corrogated or galvanized.
Looking that up, it appears the major players are "All State Tanks" of
Grove, Oklahoma, and "Columbia TecTank" of Kansas City, Kansas, both of
whom mostly erect the tanks in the field.

The web site above says "A 5,000 gallon steel tank may cost $3 per gallon"
so that's what the well guy must be talking about when he told me it would
be $20,000 to replace my 5,000 gallon steel tank.

I'd guess there are a number of other suppliers as well; there are
several more in this area than those because of the demand for ag use
tanks; depending on where in CA you are I'd expect the same for that
purpose or for the specific purposes/needs you outline.

As for the various other options --

I'd still say odds are quite high that the cost of either the bladder if
available or rigging and welding a new bottom will approach or exceed
the cost of new poly tank.

It's always worth a shot to see if can use the temporary patch that
could extend the life somewhat. My luck in welding on thin bottom of
the smaller round tanks we use (for hauling water for cattle on pasture)
has been mixed--some have turned out so thin burned thru and was given
up on and others still had sufficient overall material w/ just a few
pinholes. It'll all depend on what actually find if go in.

One thing wrt the longevity of the poly tanks -- I presuming you're in
warm weather country otherwise you would have icing problems w/ them
just outside w/ above ground piping. If so, the primary problem is
likely UV even w/ the black poly; since these are stationary application
you could undoubtedly extend lifetime by putting under roof and sun
shade on south/west sides to minimize that cause for deterioration.

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