It's a motorcycle tank in my case, but I guess the question is equally applicable to cars.
I recently bought a BMW bike that had sat for a lot time with gas in the tank. Looks like the gas managed to dissolve part of the rubber fuel lines in the tank (known problem with E10 and the lines BMW used) and also soaked up enough water to corrode the fuel level sender.
My main problem is - how do I get the dissolved rubber gunk that's hardened in some places out of the tank, and how to I remove some of the varnish if possible. All, if possible without ending up with a tank that needs to be repainted afterwards.
Any ideas? I've read about soaking the inside of the tank in Seafoam, which might work.
If 10% ethanol melted it, 100% ("denatured alcohol") should dissolve it.
Scrub it clean with ice cubes, salt, and toilet bowl cleaner. Rinse well when done.
tr8todd wrote:
Scrub it clean with ice cubes, salt, and toilet bowl cleaner. Rinse well when done.
The ice cubes are there to agitate? Awesome idea.
A layer or two of blue painters tape on the outside then a few layers of saran wrap and a top layer of blue tape to protect the outside paint. Pour in a 1/2 quart of MEK not mek sub the real stuff. Shake and let sit a few minutes and shake again and dump.
If it were steel tank I'd add a box of 3/8 external lock star washers (twisted sides tooth type).
As you already know there's a spec SAE fuel line needed for submerged lines and its not cheap.
What BMW had an aluminum gas tank?
In reply to stuart in mn:
The older K-Series bikes (aka "flying bricks") all have aluminum tanks.
Learn something new every day - a buddy has a K75, I never knew the tanks on those bikes were aluminum.
tr8todd wrote:
Scrub it clean with ice cubes, salt, and toilet bowl cleaner. Rinse well when done.
Isn't toilet bowl cleaner loaded with lye? Lye attacks aluminum.
Reviving this - I picked up a scoot with a nicely painted steel tank. It's been sitting empty since 1977 or so. It's not rusty but it's all nasty varnish. Not the gooey kind - crystals on the walls and in the bottom.
I do not want the paint damaged and I don't want it to rust after I clean it. Is denatured alcohol followed by some gas w/ two stroke oil in it enough to get the job done? I like the toilet bowl clear and ice idea above but there are lots of cleaners that fit that description... what chemical am I looking for to dissolve gasoline varnish crystals?
I actually ended up attacking the inside of the tank with a nylon brush, followed with some brake cleaner. Took a while and required a well vented area but it got the inside of the tank sparkling clean.
I'd slosh out the tank with some solvent first (gas maybe, but I also like your denatured alcohol idea), then let it dry completely. In my case all that was left at that point was some baked-on dust that easily came off using the above mentioned nylon brush.
I use whatever is under the bathroom sink. Usually the blue gooey squirt stuff. Ice acts the same as rocks and bolts, but melts away, salt acts to scour clean. When I worked in restaurants as a college kid, we would use ice and salt and dishwasher tabs to clean everything you couldn't get your hand inside. Works great on coffee pots, and anything else that needs scouring. Best part is it washes away with water and leaves everything shinny new. Only takes a few minutes to clean up the inside of a gas tank. Dry with a hair dryer for 20 minutes or so and pour in the POR15. Good as new when your done.
Has anyone tried the Stabil stuff that is suppose to protect the tank above the fuel level I the tank?
