What is the best way to clean rust out of the inside of a steel gas tank?
1976 250 MC5 Original Owner
1976 Penton 175 XC
In the past i've used navel jelly and about 200 1/4-20 nuts with the star washers stamped on to them. and shake,shake,shake...let sit over night and shake,shake,shake...again until clean. Then rinse with water, remove nuts,air dry and coat with 2 cycle oil.
Thanks Jim
The best and least expensive way I have found is plain old white vinegar. It cost a couple bucks a gallon. Fill the tank with it, add a couple hand fulls of aquarium or river gravel and as was said before, shake, shake shake! Let it sit for a day or so, then tunr over and shake again. Do this while you are working on other parts of the bike. Depending on how rusty it is, it may take a few weeks but if the tank is not needed, no problem. Once the tank is sufficiently clean, pour off the vinegar and save to use again. Rinse out the vinegar with some cheap alcohol, the flush the tank with some premix. I have never had a tank flash over with rust this way.
Another similar method is a product called Evap-O-Rust. It is available on line in 5 gallon pales, but is pricey. But it does work and does not bother paint if that is a concern.
My late younger brother had a larg tumbler in his machine shop. He just filled it with an abrasive media and let it tumble. I had the task of cleaning out and liquidating his shop and I didn't realize what this thing was at first. It was a dilapidated old piece of equipment that he got working again, and has a big selection of media on hand. I opened the lid and saw a tank inside and tried to pick it up and it was heavy. Opened the cap and it was full of tumbling media! The tank was absolutely spotless inside. One could make something similar out of an old BBQ rotisserie and a 2 by 6. Attach the tank, fill with media and let 'er rip! It would work with vinegar also, just need to make sure the tank can't leak.
Type at you later,
Dan McEntee
I just buy EvapoRust and leave it in for 24hours and then do it again. Find it on ebay very easy. Doesn't hurt paint either.
Ron Carbaugh
Thanks guys! I'll let you know how it turns out.
1976 250 MC5 Original Owner
1976 Penton 175 XC
Used white vinegar and BBs on a gunked 74 TY250 tank followed by filling tank with evaporust - tank looks as new. It took several hits with white vinegar / BBs to get the hardened varnish to let go from the bottom seam areas.
Somewhat related is my experience with a 65 Farmall 806 diesel tank which had a thick layer of bacteria build-up on bottom and scaled rust on sides and top. Tractor would only run for minutes till the gunk blocked off the supply line to the primary fuel filter. Tried evaporust first - it ate the rust but had no effect on the bacteria sludge layer. Gasoline also had no effect. I suspended tank upside down and blasted it through the fill inlet with my pressure washer. Thick chunks washed out. Got tank clean where I could see and refilled with evaporust which did its job on the previously gunked surface. This tank is baffled at both ends so the sludge is still there lurking behind the baffles and still soon caused fuel supply blockage. I added a standpipe to supply port fitting elevating port above tank bottom and tractor has run without interuption since but for how long who knows. Any body know of any chemical treatment that might eat these hidden bacterial sludge deposits?
I think the aquarium gravel is the best approach using vinegar. It has some sharp edges to help cut the rust. BB's , I think, are too smooth ans round. And I never had that many loose nuts on hand to waste getting them gunked up cleaning A tank. But whatever works for ya, I guess. Sure wish I had space to bring that tumbler back home with me!
Type at you later,
Dan McEntee