Hi KT. When I cleaned mine, this was Al's(Super A) reply on the cleaning method.
Fellers, you're making this harder than it really is! There is no need to spin, rotate, twist, turn, flip, and especially, no need to dump a bunch of little hardware in the tank that'll be a royal pain to get out!
If you use muriatic acid to clean a rusty tank, all you gotta do is set the tank level on a shop table, preferably where you can get some ventilation because the acid will give off some fumes, not a lot but if you stand right beside it, you'll get a whiff once in a while. Plug the sediment bowl hole, (use a steel plug--the M.A. will "eat" pot metal QUICK) and fill it level-full. I wouldn't use the muriatic acid full strength--I was taught a cup of acid per tank capacity, the rest is water. If you can keep it watched, you can always mix it stronger--just keep it watched, I got in a hurry once and lost a set of radiator shutters.... Full-strength would eat the whole tank out before too long unless you baby-sit it--I have used it straight out of the jug to de-rust small fasteners before and it doesn't take long for them to turn to shiny metal--less than a few minutes. let it sit over night, check it, if you still see rust maybe let it go a little longer. Dump it, flush with baking soda and water, you can then slosh around a half gallon or so of acetone to "dry" it out, and then unless you want coat it, you're ready to go...this method lets the acid solution find every nook and cranny. There will be NO rust when you're done.
I forgot--before you do anything else, if you have any old varnish in the tank, the acid won't eat it, or at least not as fast. Use a can of red devil lye and water to eat the varnish, then go with the acid once that's cleaned out.
As always, PROTECT YOUR EYES (and your skin and clothes) when working with this stuff and just use good sense. It's no more dangerous IMHO that hooking up an electrolysis rig.
Al
Rick
