Wayne, you are talking about a reasonable effort and significant cost
regardless of the material chosen, Do not use aluminum, it is far too
reactive. Do not use gavanized steel. The diesel will disolve the zinc. The
ultimate material should be 316TI SS and next best would be mild steel
blasted and painted with the special Permatex tank paint. This paint is
designed for large storage tanks and must be ordered specially. I just
finished 2 water tanks slightly smaller than yours in stainless and the
material cost was $3200 and that included access hatches.
Steve

"Wayne.B" wrote in message
...
If everything goes according to plan, I'm about to buy a Grand Banks
49 trawler that needs new fuel tanks (500 gallons each).

Any thoughts from this group on the best material for new tanks,
fabrication hints, and/or removal/installation suggestions?