Session 46: How not to clean a rusted fuel tank
I've heard ... (not tried it, but.)
a couple lengths of metal link dog collar to drop in the tank to knock off crust.
If you count how many you put in, then take out the same number, you won't have odd bits stuck in corners.
That can be problematic if you use random nuts, screws or rocks and don't do your accounting properly.
I bought 1 gallon of Evaporust rust remover. The stuff works fine, actually, really well, on rusted steel when used by itself. I tested it on some rusted wrenches and needle nose pliers and it saved the pliers from the dump. So I figured Evaporust should work well enough inside a rusted gasoline tank. And for good measure, I ran across various techniques on the inter webs such as nuts and bolts, chain and aquarium gravel. Curious to see for myself I tried a few.
I poured a gallon of Evaporust into the tank then threw in maybe 2 feet of decently sized chain. It didn't go well. After shaking it around in an attempt to scrub the rust away the chain said
and managed to randomly tie itself into a knot around an internal vent tube that was impossible to see! :wtf If you've ever dealt with a knotted chain you'll know it's a PITA. I resorted to a lighted pen shaped USB camera and a long skinny screwdriver to tease the knot apart and free the chain from the vent tube. Strike 1.
My other genius idea was clean sharp gravel from my yard. Once again, DON'T. Average size was about 3/8"(9mm) and it isn't heavy enough and was impossible to completely shake out. The main opening into a tank isn't a low spot (at least mine isn't) - more like the volcano hole at a mini-golf course. You'd think that flipping the tank upside down and shaking you'll randomly shale the gravel out given enough time. I'd say 99% came out within 10 minutes. The last two pebbles mocked me after a full hour of shaking. :mad
Eventually it took team work: my daughter operating a flex claw retreiver while I maneuvered the USB pen camera connected to my MacBook. Endoscopic procedure was a success. Strike two.
You may ask why I didn't use nut and bolts?I went to the hardware store to buy some but most fasteners are kinda rounded and safe to the hand so I figured they wouldn't do a good job of scraping. I didn't think they'd be sharp enough to scrub. In hindsight maybe they would.
Anyway, I have some triangular tumbling media that I might try.
EDIT: Add photos and clarified process.
