Where to buy fuel tanks (80-85 gal)

google using electrolysis with a battery charger to get rust out of fuel tanks

nothing else come close to being as effective and it’s simple

been doing this to old motorcycle and car tanks for years

I dropped my tank cleaned it out put some sort of stuff in it don't rember the name reinstalled still no good. Dropped tank again took it to a radiator shop re installed still no good. Dropped tank again sent it to the shop I linked to above wow came back like a work of art.
I have built a few motorcycle and always used Kreem in the tanks. The problem with any product that coats the tank you need to keep rotating it to get coverage and with the baffles in your 80 gal tank to keep the fuel sloshing around it is impossible to coat it properly.

Radiator shop

Oh, yeah, one other thing might help...don't bother with the internal fuel pump if it has one. Just install an external. Napa carries them. Doing that goes along with the extra fuel filter, if the pump is external, makes it much easier to take off and blow out any debris if the tank isn't quite as clean as you'd like.

After restoring several Classic Cars with old fuel tanks I think you have done the best that yo can to clean it. Denatured alcohol will blend with any water/fuel remaining might make it easier to get all of the liquid and debris out.
After you have it cleaned, there are several companies that make products to coat the interior of your fuel tank. If you can look inside and if the interior surfaces look clean, I would avoid using any coating products. After you have the tank assembled, I would add an additional external fuel filter, designed for engines with fuel injectors, to catch any remaining small particles that will break loose. Keep the fuel tank as full as possible after you go through all of this trouble. With a spotlessly clean interior, it will develop rust in a matter of weeks if it is allowed to sit unused and low on fuel.

If you are wanting a new tank, and you all ready have the old one out, take it to a welding shop, or machine shop and get an estimate to have a new one made. May not be very cheap, but it can be done.
Good luck

mike brez wrote:
Removed it and sent it Here. Came back awesome but was not cheap with the shipping both ways.

Probably the BEST solution !

Once read a RV'ers write up of the work he did cleaning and restoring an old gas tank from a junker RV he'd bought. Quite the story. Chains where dropped in and rattled around to knock off rust and debris, than some chemical goo to seal it up on the insides. Some patches on the outside.

Lot of work. Interesting story. Good luck with yours, hope it's an easy job!

There are many marine firms that will fabricate a tank to your dimensions. We used to use stuff call KREEM to coat the inside of motorcycle tanks that were rusty.. it worked great. Just don't know how cost effective it would be on a large RV tank.

Have you tried siphoning it out? Stand it on a corner use a 1/4" hose and siphon.