I have cleaned out probably a dozen metal small engine gas tanks in the past couple of years, 1 or 2 wound up being leakers by the time I got them clean (and thus "junk") none has been this nasty inside as the one that I am presently working on.
Most so far I just did the "fill with battery acid and let soak" anywhere from a few hours to overnite....
I have yet to try electrolysis that does seem interesting for sure.
So far this one I have tried all of the below on this 1 tank over the past 3-4 days
put about 1 qt of Muriatic acid in, slosh a bit, let sit a few hours upright with the acid in it That came out the nastiest looking, but the tank inside looked untouched.
put 2 qts of "the Works" in, let sit on edge a couple hours, then on one side overnite, then the other side all day while I was at work, came home and sloshed a bit, let sit a couple hours on its other edge, then upside down, pour out, rinse, inspect.
This too came out real nasty looking and seemed to put the largest "dent" in getting it clean. the solution was probably saturated with grunge and just could not hold anymore in solution.
Put the rest of the gallon of Muriatic in it, (about 2-1/2 to 3 quarts) and add about 1-1/2-2 qts water to "cut" it
let sit about 4 hours
Didn't come out very dirty compared to previous soakings also didn't make much of a difference. Tank looks good except for the bottom few inches, this part still looks untouched. but now on the edge closest to the cap (can't see other edge on account of baffle) it looks like a heavy layer of rusty varnish that is keeled over like a coating that is peeling away. To my knowledge this tank had never been previously coated with anything. probably just a bad layer of varnish left, I'm guessing.
I had this tank given to me about 3-4 years ago by a buddy that moved away and "was gonna scrap anything that he offered me that I refused to take" as he cleaned out his old place... several things that he told me to take that I set aside because I didn't want, that I found in the bed of my truck when I got home from a day of helping him pack and clean..... wow
Last nite I filled it to the brim with battery acid. I just emptied it, rinsed it, no change. This batch of battery acid, I salvaged from a couple of old car batteries before they got junked a couple of years ago, and have cleaned probably 6-8 tanks with the same batch of acid in that time.... getting weak maybe?
Just 15 minutes ago I poured what Lacquer thinner I had here, in. No more than a pint. Hardware store quality. I then went and got my surely weakened from new, (well used) Berrymans carb dip and poured that in on top of the lacquer thinner. probably about 2 quarts there, definitely enough to cover the portion of the tank that still looks so nasty. I'll let that sit a while and see what that does.
I got front brakes, an oil change, some radiator hoses to change on the old Durango along with some AC work, so I'll pour this stuff off after that and see what it looks like.
These style tanks have gone thru the roof in cost, even used on Feebay. Some of the plastic ones aren't that cheap either.
so as long as I don't eat a hole in it before I get it clean it'll probably be worth salvaging.
this is the last one I have laying around any more. I hope to be able to use it on my Swisher Trailmower that I brought home last weekend. It has a transplanted engine but no tank. If it cleans up and doesn't wind up leaking I will make a pair of brackets to mount it, already got those built, in my head.
I gave away the tank I probably should have used on this mower a couple weeks ago to a neighbor who had been asking for a gas tank for a project for a while, one that I did not even know I had
that was a plastic Tecumseh 1-gallon tank like they usd on most of their snowblower engines.
Hmmm I set that one next to the garage door and never told him that I'd put it there... I wonder if he even knows it's there yet?
Naaah can't do that, I don't wanna be an "Indian giver"...
Edited by dodge trucker, May 31, 2014 - 11:27 AM.