Gas Tank Clean Out

[razz2234]

It's been a while ago but I recall there was a thread about someone who had a better idea to clean out the gas tank, so it won't be cumbustable, prior to doing a bead blast and paint job. Can anyone recall that thread or have any suggestions. I'd like to clean it out and get rid of all the fumes...also be able to leave it in a condition so it won't rust.

Thanks...:thumb

[20774]

A search found this:

http://www.bmwmoa.org/forum/showthread.php?t=39063&

Not sure if this was it...

[jbcollier]

Phosphoric acid available at hardware stores as concrete cleaner.

[DennisDarrow]

You might search for POR 15 threads. The treatment cleans out the tank and the coating is definately rust proof.........Good luck......Dennis

[iriematt]

a local radiator shop soaked my /5 toaster in their dip tank over a weekend for $30 with excellent results. this stripped it down to bare metal inside and out. the inside was trashed beforehand, with varnished gas and surface rust after sitting in a barn nine years.

[awshucks]

I remember reading a thread on this. Someone had used "The Works" toilet bowl cleaner, I think a whole bottle and added water to fill tank, let set for 20 minutes and was pleased w/ result. $3.00 or so.

[RoboRider]

You don't have to get carried away for what you're doing. I weld on tanks, and I take a bit more precaution for that. Blasting and painting--no big deal.

Even so, for welding, the key is to use a transitional solvent. Ethanol works well. A transitional solvent is one that is miscible in both phases. For example, gasoline does not dissolve in water. So water is tough to use to wash out gasoline. But, ethanol (Home Depot) will mix with gasoline and washes it out well. Ethanol is also miscible with water, so you can easily use water to wash out the ethanol. If you do this, rinsing well, you can safely weld the tank if needed.

Use the reverse to go back to gasoline. Wash the tank with ethanol to remove any left over water. At that point, just let it sit and dry naturally and when it is back on the bike it will be ready to go for gasoline.

I never thought about the radiator shop, but I won't forget that. The picture of the tank looks great.

Phosphoric acid (Naval Jelly--mixed about 1:5 with water) is excellent to soak the tank in (after the ethanol rinse) to remove rust. I had rust inside an old Night Hawk tank and a couple of hours in the acid rinse cleaned it bright and shiny. If you don't have rust, I would not bother with the phosphoric acid.

And finally, I know they make coating kits that you can recoat the inside of the tank if it is in bad shape. That doesn't apply here, but sort of completes the "tank restoration" thoughts. Between washing and welding and acid washing, I've never needed the coating kits, but I've heard others report they work well.

[CTellman]

I did my tank last Spring. I used POR 15 and had great results. At least I no longer have scaling or plugged filters.
POR 15 was avery easy system to use. I was careful of the outside of my tank and it was not affected. I put some brass screws in with the cleaner and used some rubber bottle stoppers to seal the petcock holes. I shook it off and on for two hours. The acid was not abjectionable.
Ospho or phosphorus acid turned rust into something inert. After drying on a lightbulb I recoated.
Good Luck!
Campbell Tellman II
'93 R100RT
:thumb