The Results Are In.....

I decided to take the plunge, so to speak, and try out the electrolysis tank cleaning trick. I had a nicely rusted tank from a 70 or 71 TS90 Suzi trail bike that was otherwise in pretty good nick....well it's got a few small dents....but also has nice original orange paint and nice striping, etc. I figured it'd be the perfect candidate because if the solution attacked or stained the paint, no probs......but if the whole thing worked, the tank may be of some use to someone someday.
Our shop has a dual setting 2/10 amp charger to power the whole process and I splurged and bought the giant economy box of Arm & Hammer Super WASHING Soda
to use as the electrolyte. An old coat hanger served nicely as the sacrificial anode and I picked up a couple of sizes of flattish rubber stoppers to isolate the anode from the tank itself.
The whole thing works like a hot darn. Most of the rust was gone in about 4 hours with one change of electrolyte (which wasn't really required...but I did it anyway) and numerous cleanings of the crap that builds up on the anode. This was on the 10 amp charger setting. You could use the 2 amp setting but the whole process will take a lot longer.
It will need more time to get it absolutely spotless but it was a good first time experiment.
Everything went so well that, since one of the techs was making one XL185 out of two and had everything he needed except a rust-free tank, I decided to forge ahead and try out my new-found expertise. About 2 hours saw the XL tank cleaned up nicely to where it wouldn't clog up the carb jets with rust any more....but it was still not as nice as it could be. I think I'll give it another 2 or 3 hours tomorrow and see what that will do for the remaining spots that are still visible. This tank was not nearly as bad as the Suzi tank so should end up looking quite nice when I'm finished with it.
More news tomorrow night when the tank has been subjected to a little more "therapy".
As it stands, I'm sold on this method. It's cheap, it works, it can done in your basement with a low cost battery charger.....what's not to like ??!!??

You know we are going to need pictures of the "before" and "after" to believe you.

Sorry, Corey.....no "before" pics exist.....and "after" pics are pretty much useless without something to compare them to. However, the next tank I do I'll be sure to take some pics. I've only got a 4.1 MP camera so the details won't be too clear, even on the macro setting. The inside of a tank is a pretty dark place, after all.
Trust me on this, though. After 40+ years of messing with bikes and 20+ years of messing with OLD bikes, I've tried a variety of methods to resurrect rusted tanks. The electrolysis method is by FAR the easiest and most cost effective method I've ever used....and it won't hurt your paint. As I said in my original post: What's not to like ??