Topic: Rusty Tank - Thoughts?

[Hills2Horizons]

When I first re-did the tank a few years ago it was a lengthy process. Almost a week of nuts and bolts swimming around in acid, shake, shake, shake, dump, refill, repeat. But I got it cleaned up pretty well to where I wasn't nervous about running it.

Then - I opened the cap last night (photo) after it has been sitting since probably 2017-2018 with no fuel in it.

Thoughts? Should I just start the process again? Obviously the tank hadn't been repainted when I did it last time so I didn't care about the acid on the paint, but I do now. Would it be better/easier to just coat the inside?

[Pbeattie89]

I personally dislike coating. There are too many horror stories of them failing, and they are way harder to remove than the rust. I've used vinegar with decent success. If you spill any on the paint, just rinse it off with water. Let it sit for 24 hours and then drain. I then half filled with water and added steel BB gun ammo and shook it up to knock everything loose. The BB gun ammo is easy to fish out with a magnet. Then rise with plenty of water and repeat if needed. After it's done to your satisfaction, just coat the inside with a little two-stroke oil if it's going to sit or fill it with gas.

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[MauiK3]

electrolysis works, it's a little fiddly to set up but it works.

[Pbeattie89]

electrolysis works, it's a little fiddly to set up but it works.

Brick house builds did a video of it on youtube.

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[Don R]

 I've used the Evaporust, muriatic acid and vinegar methods. Recently I did a couple and used vinegar as a pre-treatment followed by Evaporust. I did it that way to save the expensive Evaporust for several uses.
 Cleaning vinegar is stronger than cooking type, I used a mix of both, I found the cleaning vinegar at Menards and added it to the cooking type that I already had. I left a trouble light bulb under the tank because it was cool in the shop and the process works better when it's not cold and it's the same with Evaporust.
 The rusty cleaning vinegar makes a safe weed killer when you're done with it. It for sure needs oiled when done.
  I used northern blue tank liner in my goldwing, so far so good but in a 750 tank it didn't do a lot.

[newday777]

When I first re-did the tank a few years ago it was a lengthy process. Almost a week of nuts and bolts swimming around in acid, shake, shake, shake, dump, refill, repeat. But I got it cleaned up pretty well to where I wasn't nervous about running it.

Then - I opened the cap last night (photo) after it has been sitting since probably 2017-2018 with no fuel in it.

Thoughts? Should I just start the process again? Obviously the tank hadn't been repainted when I did it last time so I didn't care about the acid on the paint, but I do now. Would it be better/easier to just coat the inside?

It rusted from not coating it with 2 stroke oil when you emptied it.
Yes now you will need to derust it again before you use it(even if you decide to line it....I don't advise lining your tank.....).
Electrolysis cleaning works great with no damage to the paint. I have derusted many tanks this way, some have been rusted more than your tank is and have had great success. I follow up after rinsing out the washing soda mix with fresh water, dump out, then fill with Evaporust to the top for a couple days. Then dump the Evaporust back into the 5 gallon bucket to reuse on another tank. Then rinse the tank 4 times with 2 quarts of diesel fuel and shake to rinse and capture the moisture of the Evaporust. I dump the diesel fuel into another clean 5 gallon bucket (to save), pour in 2 more quarts of diesel fuel and shake again, repeat this rinsing 4 times. (The moisture separates and settles to the bottom of the bucket after a few days and you can drain off the diesel fuel to use the next time)
Then I coat the tank with 6-8 oz 2 stroke oil turning the tank so it coats all over including the top of the tank, then dump the excess oil. The coating will mix with the fresh gas you put in when you fill it. It won't hurt the carbs or motor. You can add 2 oz of 2 stroke oil to each fill up to preserve the tank will you are riding the bike too.
And you don't have to line the tank either, as long as the tank doesn't leak anyhow..
I drain my tanks each winter for storage and coat the tank with 2 stroke oil to preserve the tanks.

[Hills2Horizons]

It rusted from not coating it with 2 stroke oil when you emptied it.
Yes now you will need to derust it again before you use it(even if you decide to line it....I don't advise lining your tank.....).
Electrolysis cleaning works great with no damage to the paint. I have derusted many tanks this way, some have been rusted more than your tank is and have had great success. I follow up after rinsing out the washing soda mix with fresh water, dump out, then fill with Evaporust to the top for a couple days. Then dump the Evaporust back into the 5 gallon bucket to reuse on another tank. Then rinse the tank 4 times with 2 quarts of diesel fuel and shake to rinse and capture the moisture of the Evaporust. I dump the diesel fuel into another clean 5 gallon bucket (to save), pour in 2 more quarts of diesel fuel and shake again, repeat this rinsing 4 times. (The moisture separates and settles to the bottom of the bucket after a few days and you can drain off the diesel fuel to use the next time)
Then I coat the tank with 6-8 oz 2 stroke oil turning the tank so it coats all over including the top of the tank, then dump the excess oil. The coating will mix with the fresh gas you put in when you fill it. It won't hurt the carbs or motor. You can add 2 oz of 2 stroke oil to each fill up to preserve the tank will you are riding the bike too.
And you don't have to line the tank either, as long as the tank doesn't leak anyhow..
I drain my tanks each winter for storage and coat the tank with 2 stroke oil to preserve the tanks.

Hello - I can't believe that's even the same tank. It looks GREAT. I can't remember what I coated it with but you are correct in that it was not 2-stroke oil, I do know that much.

[Hills2Horizons]

Electrolysis cleaning works great with no damage to the paint. I have derusted many tanks this way, some have been rusted more than your tank is and have had great success. I follow up after rinsing out the washing soda mix with fresh water, dump out, then fill with Evaporust to the top for a couple days.

So for this did you essentially just use the tank itself as the 'electrolysis tank' instead of submerging it INTO an electrolysis tank? If so that seems very straighforward based on with I just watched on how the process is done. Where did you attach the leads for the electrical current? Just around the gas filler neck?

[calj737]

If you flush your tank after de-rusting with diesel fuel, you need not treat it with anything afterwards. Diesel is a high petroleum content liquid and leaves ample protective residue. Once you fill the tank with gasoline, the gasoline will dilute any remaining diesel, and the small percentage of diesel in your fuel will not be detrimental to the proper running of your bike.

For a freshly painted tank, I would strongly encourage you to avoid any acid of any type. Even vinegar can stain the paint if it makes any contact. And all acid-based solutions attack the parent metal. Evaporust or MetalRescue or electrolysis are your safest bets.

[The Lone Builder]

I have used both electrolysis and vinegar. The former is slow and the latter even slower!

The main problem I found with electrolysis was to get a suitable shaped electrode and then making sure it wasn't touching the tank. That said, it worked well.

[rotortiller]

Gotta love that POR-15 tank liner stuff. If used correctly the first time around you likely would not be in this situation. I did the pictured tank back in 2017 and it's still in the same condition. Maybe try vinegar and that evapo crap then etch carefully with POR-15 metal prep then use the good stuff .  Do not make the tank airtight when using vinegar or it will pop lol.

[willbird]

I just poured mine 100% full of Evaporust. Left it in about a week. I have another one to do with he same 5 gallons of Evaporust. The 5 gallon bucket full of it has had quite a few other things submerged into it too. I did not run out and get 5 gallons I just kept picking it up until I had enough to fill it all the way up.


Bill

[newday777]

Electrolysis cleaning works great with no damage to the paint. I have derusted many tanks this way, some have been rusted more than your tank is and have had great success. I follow up after rinsing out the washing soda mix with fresh water, dump out, then fill with Evaporust to the top for a couple days.

So for this did you essentially just use the tank itself as the 'electrolysis tank' instead of submerging it INTO an electrolysis tank? If so that seems very straighforward based on with I just watched on how the process is done. Where did you attach the leads for the electrical current? Just around the gas filler neck?

Yes.
The negative goes on the back tang that the rear rubber holder grabs the tank in place. I sand off the paint
The electrode gets the positive lead.

[HondaMan]

Then - I opened the cap last night (photo) after it has been sitting since probably 2017-2018 with no fuel in it.

It rusted from not coating it with 2 stroke oil when you emptied it.
I drain my tanks each winter for storage and coat the tank with 2 stroke oil to preserve the tanks.

I've long done something similar to this: after the vinegar (or whatever treatment) is used, I immediately soak the inside with oil, sometimes the 2-stroke kind. Then when using the bike, I always add a bit of oil to the gas at fillups (the 2-stroke oil stalls the ethanol's ability to strip lube from these older engine's combustion surfaces, and gas tanks, and carb bowls, etc.) and when I park it, I fill the tank fully up with the oil-treated gas. I've usually just fired up the bike and run it out with no trouble, even 2 years later. Meanwhile, 2-year-old untreated gas (i.e., no 2-stroke oil added) in a metal or plastic container won't even start my Honda mower, so the oil is helping quite a bit.

If it gets so bad that the tank needs coating, I can recommend the POR15 kits. Not simple nor quick to install, but seems to last forever. I have customers' bikes now with 15 years on POR15'd tanks, no grief at all.

[carnivorous chicken]

If it gets so bad that the tank needs coating, I can recommend the POR15 kits. Not simple nor quick to install, but seems to last forever. I have customers' bikes now with 15 years on POR15'd tanks, no grief at all.

I'd second (third?) that as well. I've had POR15 treated tanks with 15+ years of no issues as well. As long as you do it correctly, it seems to work well.

I'm about to repaint a 350F tank, and the rust isn't that bad but definitely needs cleaning. I'm always wary of people who recommend something acidic to clean as it's going to affect the metal, and I'd hate for a newly painted tank to develop pinhole leaks...

[willbird]

It would be kind of cool to find some kind of hollow neutrally buoyant ball to use in the tank with evaporust to reduce the quantity actually needed to fill the tank. I seem to recall seeing somebody had made something to move rotate a partially filled tank to keep the entire inside wet ??

[calj737]

It would be kind of cool to find some kind of hollow neutrally buoyant ball to use in the tank with evaporust to reduce the quantity actually needed to fill the tank. I seem to recall seeing somebody had made something to move rotate a partially filled tank to keep the entire inside wet ??

Golf balls.

[willbird]

It would be kind of cool to find some kind of hollow neutrally buoyant ball to use in the tank with evaporust to reduce the quantity actually needed to fill the tank. I seem to recall seeing somebody had made something to move rotate a partially filled tank to keep the entire inside wet ??

Golf balls.

Do they fit ?

[britman]

I am very old, therefore so are my methods.  A large hand full of dry wall screws, a few good size nuts for good measure.  A quart of acetone mixed with some lacquer thinner, then come  to doing the shimmy shake for about 15 or 20 minutes.  Empty the tank, a very strong magnet on a wand is a very good friend at this point in the process.  Rinse with a little more thinner and blow out the tank well with compressed air.  I usually let the tank air dry in the sun for a day or two.   For coating I use nothing but Caswell tank sealer, I have never had a failure, it has even sealed pinholes in few really bad tanks, and I order directly from the company website.  I just ordered the MC tank kit for a CL77 project and it arrived within a week......

[Stev-o]

I just poured mine 100% full of Evaporust.

How did you plug the petcock bung?

[willbird]

I just poured mine 100% full of Evaporust.

How did you plug the petcock bung?

I just left the petcock attached.

Bill

[carnivorous chicken]

I just poured mine 100% full of Evaporust.

How did you plug the petcock bung?

I buy rubber stoppers -- just bought some at Ace Hardware on my recent trip back to the States (I'm sure they exist here, couldn't find them at the places I tried). One big one for the top, one small one for the petcock hole, and I usually just use the two mounting screws with washers (for the 350F). Screw-on types are just one hole to plug of course...

[britman]

Two petcock screws, a piece of old innertube, and a piece of aluminum cut to fit the the opining.   Rubber on the inside and bolt it up, works great....

[Don R]

 All good advice. I would remove the petcock, a friend bought my brothers XS1100 and de-rusted the tank with the works toilet cleaner with the petcock installed. It blew up, he had made what's known as a works bomb. I plugged a couple petcock holes with 6m screws wrapped with teflon tape and a golf tee in a rubber hose in the fuel hole.
 The last one I did I made an aluminum plate drilled for the 6m bolts and used an awl to poke the bolt holes in a rubber gasket, then thread the bolts through the rubber and into the tank.

[carnivorous chicken]

All good advice. I would remove the petcock, a friend bought my brothers XS1100 and de-rusted the tank with the works toilet cleaner with the petcock installed. It blew up, he had made what's known as a works bomb. I plugged a couple petcock holes with 6m screws wrapped with teflon tape and a golf tee in a rubber hose in the fuel hole.
 The last one I did I made an aluminum plate drilled for the 6m bolts and used an awl to poke the bolt holes in a rubber gasket, then thread the bolts through the rubber and into the tank.

I always undo a stopper after shaking around and when it's just going to sit for a while...