gas tank problems

so i was trying to clean the rust out of my gas tank, first i tried using the battery charger method to clean it but i ended up with a big lump of washing soda stuck on the bottom of the tank, hard as a rock. after i broke it up and got it all out it still wasn't that clean, so i bought some muriatic acid and it ended up eating holes on the bottom of the tank.
If anyone has a tank for sale or for trade that would be great! i am making a bobber out of my 82 maxim 550 so i have lots of parts i can use for a trade just let me know what you need.
also does anyone know a right way to clean a tank? this was the biggest pain on this bike.
thanks

 

It is likely that yours was just too far gone both electrolysis and an acid wash are valid ways to clean a tank.

 

How I did it was a combination of phosphoric acid(which they sell as concrete etcher at Home Depot, if I recall) and a bunch of wood screws. The idea is to rattle the screws around in the tank to scrape off any bad rust, and the phosphoric acid cleans up the rest, and leaves a sort of protective film behind once you take it out.

The nice thing is that phosphoric acid isn't all that corrosive, I mixed it 50/50 with water, then I think when I was done, poured some baking soda in there and poured the whole mess down the drain. Coca-cola has phosphoric acid in it, after all. But if muriatic went through yours, sounds like it was shot. Mine was just surface, or what they call "flash" rust. Anything that has compromised that tank, no amount of cleaning will help.

Some people like those "tank liners" that put some kind of goop all over the inside of tank, like a plastic bladder. Can't say I'd do that, but might be an option if you don't want to clean your next one. The problem is those things can slough off pieces that end up in your carbs, no thanks.

Edit: and the wood screws were more trouble than they were worth. Took forever to get them all out, and by then they were wet covered with all the gunk I'd put in tank, plus whatever was in there, gross.

 

thanks maximike, if you use the muriatic acid "like i did", how long would you leave it soke in the tank for. because i think i might have left it in there for to long. i put in in the tank at around 2am, and when i emptied it it was around noon. was that to long? or was the tank shot.
also with the wood screws that was the first thing i did, but i could not find anything to shake the tank with. what did you use?

 

Oh, haha, I used my hands to shake it. It was more like just rocking it back and forth and around until I felt like they had make contact with every surface.

I don't know how long is too long for Muriatic, I've never dealt with that stuff. The phosphoric I think I left it a couple hours, maybe less. I didn't want to leave it too long just because of the water that was also involved. I didn't mention before, but I've used a lot of "naval jelly" to deal with rust, and phosphoric acid is the main ingredient in that.

The main thing I would say is once you do get your tank clean, try to keep gas in it. A dry tank is a rusty tank, in my experience.

 

Here's a good tank thread.

http://www.xjbikes.com/Forums/viewtopic ... rt=30.html

It may be that BigFitz's recommendation is why I did Phosphoric, maybe it was just cheapest option. I only did it because I had to replace my rust-free but VERY dented tank for a slightly rusty tank from the internet.

It sounds like he's saying just rinse the tank in the acid, not really letting it sit. To be honest, that sounds right, if I recall my chemistry, letting it sit there won't do much. Whatever's gonna happen will happen in a few minutes. But again, your original tank might have been beyond saving, who knows.

 

Way too long! Muriatic acid is a powerful acid around 2pH. 30 minutes for surface rust and never more than 90 min total. But it should only be used as a last resort and on metals that are fairly stout to begin with.

Better way: Use an aqueous (water based) cleaner to remove the gum, varnish, etc. This would be a 'basic' as in opposite of acid cleaner. Por-15 makes 'marine clean', but you can also find the same basic stuff at any home improvement store-Its also what is found in 'Easy Off' stove cleaner. Mix cleaner and VERY hot water 1:1 or 1:2 (cleaner/water) and agitate in tank thoroughly. Can be left in for a day or two if you have a really dirty tank, repeat then thoroughly rinse. Next use a phosphoric acid metal prep which will remove the rust and etch or prep the metal. Rinse again thoroughly (no need to neutralize this acid like muriatic). You can stop here if your tank looks good as in rust and pitting are non-existent, but you should immediately coat your tank with oil or upper cylinder lube to prevent any flash rusting. If your rust was bad you will need to coat. The only product that I know of that works long term is the POR-15. It is a hyrdophilic curing solid based paint (it cures faster when atmospheric moisture is present, which is clearly opposite of all other petro based paints), and will not deteriorate in the presence of fuel or ethanol-if and only if your tank is FULLY clean and TOTALLY dry.

Once done your tank should outlive your engine.

I'm not a big fan of throwing in abrasive metals. Unless you work the tank over and over you will never get enough off to justify the effort. I suppose you could wrap it up in pillows and throw it in the dryer, but of course that probably carries other risks!

Jthomas you might still be able to salvage that tank if the holes aren't very large.

 

Huh. Mine had all hella rust scale and fuel varnish. I got a gallon of cheap vinegar and 6 ft of that cheap twisted wire chain like you'd tie up a dog with...and threw a dozen bolts and nuts in there...shook it like crazy every couple of hours, let sit over night, shook every couple of hours all day...dumped it out, looked like new...

 

Anyone have luck removing old, peeling tank liners? My bikes' PO must have done a crappy job with his because the inside of my tank is developing leprosy.

Also, for people who want to shake their tank for an extended period of time without killing their arms just wrap the whole thing in some old blankets/duct tape and throw it in the dryer with no heat. Laziness is the mother of invention.