Was just given a 1980 Suzuki GS 850 that hasn't been run in 10 years. There's maybe a couple ounces of liquid "gas" left which I'll evacuate but what have you guys to get the muddy, rusty goo and rust out.
YouTube says muriatic acid, white vinegar, drain cleaner, and toilet cleaner. Drop in nuts and bolts and shake the E36 M3 out of it?
What's the truth, in real-life, between friends?
Soap, water, rocks, shaken not stirred.
Vinegar and rocks works as well.
Rocks works better than nuts and bolts because they have some abrasive quality.
If you have a cement mixer, you can stick the tank in there, pack foam around it and turn it on for a while.
In the Kristi thread, we learned this week that muriatic acid is the terraforming miracle chemical of the gas tank world.
Also - awesome! I love old free motorcycles!
Always a great opportunity to clean your rusty tow chain/bucket full of misc hardware. 
I affixed a tank to an axle stuck on the crotch of a tree with a spoked wheel on the end. Then I dumped all the lug nuts I had (about 50) along with naphtha. Spun out around, let it soak, spun out around more, let it soak more. Dump, repeat. Switch to diesel. Finally came out clean. <img src="
" />
<img src="
" />
<img src="
" />
So muriatic acid, lengths of chain or nuts/bolts/washers/sharp stones and shake the tank until I start to hallucinate?
Then wash/rinse with baking soda?
XLR99: I might do a build thread. This bike is my re-entry into two-wheeldom.
(Huge thanks to my friends Dave, Neil, and Glenn for making it possible)
Apple cider vinegar and some rocks.
Wrap it in a couple blankets and toss in the dryer on no heat.
BBs are great for this kind of thing. Think of it as low speed shot peening.
Brett_Murphy wrote: BBs are great for this kind of thing. Think of it as low speed shot peening.
I have many. I've seen it posited that sharp edges of nuts and bolts are more apt to loosen the rust rather than smooth BB's
I can see that, and the nuts and bolts get clean, too. I'd just worry about messing up the threads on the bolts.
If you're going to use a strong acid like hydrochloric (muriatic) you shouldn't need anything else in there.
What toyman said except don't use rocks either. Go to harbor freight and buy this
http://www.harborfreight.com/5-lb-rust-cutting-resin-abrasive-tumbler-media-60542.html
instead of using gravel. It's supposed to be for a vibrating tumbler but a tank full of seafoam and these little beauties work really well.
Let it sit for a couple hours then shake, shake, shake. Shake your fuel tank. Do not sing that.
get a bottle of one step toilet bowl cleaner dump it in the tank add a cup of salt and pack the tank with ice cubes once its full shake the living E36 M3 out of it the end result is the ice melts and can simply be rinsed out you will be amazed at the results and you wont spend three days trying to get any solid abrasives (like rocks bb,s ect out of the tank) glenn
In reply to glenzo654:
Salt? As an abrasive? Just asking because I'd be concerned that the salt would promote corrosion. But maybe it gets washed out completely if you do it right?
I take mine to a radiator shop. They make it look new for about $30.
i got a price for a tr7 tank at a"local radiator shop" they wanted 600.00 thats alot of toilet bowl cleaner!
I just cleaned a tank that's been sitting for 15 years. Straight acetone and 25 old bolts made it very clean. I let it sit for a couple of days with an occasional shake. Muratic acid or vinegar if there's rust.
Trans_Maro wrote: Apple cider vinegar and some rocks. Wrap it in a couple blankets and toss in the dryer on no heat.
DO NOT PUT AN OLD FUEL TANK IN YOUR WIFES DRYER!
I tried to heat up a connecting rod in our oven once to install a press fit wrist pin. It got all smoky and smelly. Not just the oven, the whole apartment. My wife got pretty upset.
The best way is electrolysis. I used it to great success on a CT90 Honda. All you need is washing soda, a batter charger (6v or 12v is fine), a piece of iron, a board and some water.
http://www.instructables.com/id/Electrolytic-Rust-Removal-From-A-Motorcycle-Gas-Ta/
Me i like Star lock washers. If it just rust I inside star washers with evaporust. if there's goo inside MEK and star washers.
gearheadmb wrote:Trans_Maro wrote: Apple cider vinegar and some rocks. Wrap it in a couple blankets and toss in the dryer on no heat.DO NOT PUT AN OLD FUEL TANK IN YOUR WIFES DRYER! I tried to heat up a connecting rod in our oven once to install a press fit wrist pin. It got all smoky and smelly. Not just the oven, the whole apartment. My wife got pretty upset.
What part of "no heat" did you miss?
Just how gunky is it? If it's just some sludge in the bottom you can rinse that out with some fresh gas swirled around for a while. On the other hand if there's rust and hard chunks in there you'll have to resort to harsher methods.
One caveat - a buddy of mine took a motorcycle tank to a radiator shop to get boiled out; when he went to pick it up, the inside was clean but in addition all the paint was gone off the exterior. So, if you take it to a shop, find out just how they do it before handing the tank over.
The GS850 was a pretty nice bike, one of my friends bought one new. It was a little on the slow and porky side compared to other bikes in the GS line, but the shaft drive was pretty nice and it was very comfortable for long highway rides.
In reply to stuart in mn:
It's rusted and has a bit of liquid gas (you know, that good smelling stuff?).
It's gonna need de-varnishing AND de-rusting.
Electrolysis and I'm not going to say it again. :) You don't need to use a handful of washers, nuts and bolt or gravel.
Muriatic acid does a great job of cleaning a rusty tank but it will flash rust after. I've neutralized the acid after and coated the inside with AFT but the flash rust keep rusting. Last tank I did I used phosphoric acid after the Muriatic. It's less aggressive then Muriatic but will leave a zinc phosphate coating. My 280z tank still looks great inside 4 years later. For a tank that doesn't have heavy scale inside just using phosphoric acid should be enough.
You'll need to log in to post.
