Fuel Tank Electrolytic Rust Removal

[3Phase]

I used TsP and a battery charger to remove the rust from the fuel tank of my XS1100G (Standard). It's easy to do!

The most difficult part of the whole job is making leak-proof cover plates for the fuel petcock and guage mounting holes.


Here we go!

First and foremost: Flickr's rules say that I have to link back to the photo page on Flicker so here is the set in a Flickr slideshow!

Now, with that out of the way -- here are the pictures.
Click any picture to view a larger size.


Rusty gas tank filler neck




Rusty tank seen through filler neck




Rusty tank seen through fuel guage mounting hole




Rusty tank and overflow tube seen through left fuel petcock mounting hole




Rusty tank and overflow tube seen through right fuel petcock mounting hole




Rusty upper rear of gas tank seen through right fuel petcock




Temporary cover plate for fuel gauge mounting hole




Temporary cover plates for fuel petcock mounting holes




Temporary cover plates mounted on the tank




Old steel tent stake for the anode and a plastic cabinet hole cover to keep the end from touching anything inside the tank




Plastic cabinet hole cover mounted on the old steel tent stake to keep the end from touching anything inside the tank




The rubber fuel tank mount makes a good insulator and won't fall into the tank. Add another plastic cabinet hole cover and a plastic washer so the anode won't slide through the insulator into the tank, then put a short piece of vacuum hose over the anode to keep it from touching and shorting to the inside edges of the fuel filler neck




I used TsP for the electrolyte




TsP has Sodium Carbonate for the electrolyte




Use one heaping paint can cap of TsP for a 5 gallon fuel tank




Put the TsP in a bucket and add hot water to dissolve it




Carefully pour the concentrated electrolyte into the fuel tank filler neck




Finish filling the tank with hot water and check for leaks




The electrolyte should come up to the top of the fuel filler neck so keep adding water until the level stays constant




Attach a battery charger:
Positive (Red) lead to the anode in the filler neck
Negative (Black) lead to the rear tank mount




Set the battery charger to Manual, 12 Amps / 12 Volts




Watch for short curcuits when you turn on the battery charger so the charger is providing about 1 or 2 amps through the electrolyte




After one hour the anode is already pitted and dirty




After one hour the anode is pitted and dirty and the electrolyte is no longer clear




Well, wasn't that fun?

Here is some more detailed electrolytic de-rusting information from stovebolt.com.


Regards,

Scott

[CatatonicBug]

OK, so where are the pictures of the inside of the tank AFTER the electrolyte is removed??

[3Phase]

OK, so where are the pictures of the inside of the tank AFTER the electrolyte is removed??

Right now the tank is still out in the garage, cooking. I'll take some more pictures tomorrow as I work.

The rust pictures are from last month when I pulled the tank and checked it for the first time. I didn't notice it until I pulled the tank this afternoon to take some more pictures of the process but it had rusted up again slightly. When I bent a valve rebuilding the engine I forgot to finish drying and properly store the tank so I'm doing it over again.


Regards,

Scott

[red bandit]

What negative effects would happen if you left the float & petcocks in? Would it remove the coating on the inside of the petcocks?
If the tank is rusty wouldn't the float "metals" be rusty too? If it's rusty wouldn't it worth it to leave it in or would it damage it somehow?

[oseaghdha]

Petcocks are just pot metal. They won't rust, but you would have all that garbage in your screens if you leave them in.

[petejw]

Nice work Scott.

[tarzan]

Hey Scott where did you get that TSP?At a hardware store?
Rick

[81xsproject]

You can save yourself some money and buy JUST sodium carbonate at pool/hot-tub stores as soda ash. There are already a couple write-ups on this. HERE is the one I wrote. It is currently floating in the 'Tips Under Construction' section of the forum. There is also a decent write-up on the 650 forum which is where I started.

[FANNING507]

Well done. This needs to be added to the technical site!

[CatatonicBug]

Hey Scott where did you get that TSP?At a hardware store?
Rick

I have always used TSP for cleaning bedroom walls prior to painting them. Been doing that since I was a little kid. We always bought it at the grocery store. They might have it at Walmart too.

[3Phase]

After De-rusting

Okay, this is what it all looked like this morning. A lot of the black, converted, rust rinses and wipes right off but it's inside the tank so it's difficult or impossible to reach all of it. I rinsed the tank with COLD WATER, then flushed, sprayed and rolled almost a full can of WD-40 into the tank to keep it from rusting again.

There is an air bubble in the electrolyte that forms at the top of the tank. That can't be avoided and it leaves a ring of untreated rust around the fuel filler neck. I'm thinking about the best way to deal with it:-

Leave it alone, you're obsessed with rust!

Inverted immersion in a large tub of electrolyte would de-rust the outside of the filler neck and the area inside the tank but it would be difficult to get the anode into the filler neck without shorting the anode or submerging the connector.

Standing the tank on each end and on each side with the anode in the fuel filler neck would work but it would require four steps.

Inverting the tank with the fuel filler neck plugged and threading the anode through the fuel gauge mounting hole to just above the fuel filler neck would work but, again, it would be difficult to do without shorting the anode.


Again, here is the complete slideshow on Flicker.


Get on with the pictures!

The fuel level guage was not rusted and did not need cleaning at this time. It's a different type of steel than the tank and doesn't rust quite as easily




The anode after working 14 hours overnight




The electrolyte after 14 hours overnight




Black bits of rust rinsed out of the tank when the electrolyte was flushed




The de-rusted tank floor seen from the fuel filler neck




The still-rusty fuel filler neck will have to be de-rusted again




The de-rusted left tank wall seen through the fuel gauge mounting hole




The de-rusted tank top and overflow tube seen from the left fuel petcock mounting hole.
The area of rust around the fuel filler neck that was caused by the air pocket at the top of the tank will have to be de-rusted separately




The de-rusted top rear of the tank contrasts with the area of rust that remained because of the air bubble aaround the fuel filler neck




81xsproject: vBulletin Message says, "3Phase, you do not have permission to access this page."

I think I read your write-up at the 650 site -- nice work! I haven't seen Washing Soda for ages and I have TsP on-hand. I don't remember where I bought it but if I can't find more I'll hit up my buddy with the pool cleaning service for a couple of pounds of Sodium Carbonate.

Red Bandit: The tank would have to be put on blocks to keep the tank level and prevent damage to the petcocks while the tank is being de-rusted. It would make a real mess when you tried to clean and oil the tank after flushing out the rust and electrolyte.

It also makes it difficult to take pictures.

So, it wouldn't hurt anything to leave the fuel gauge and petcocks in the tank but they really should be cleaned and inspected while the tank is being de-rusted. The block-off plates are easier to work with and they're almost impossible to damage.


Regards,

Scott

[latexeses]

Looks great!

I used the Arm&Hammer washing soda. Similar looking insides.

This is 45 minutes after I started the charger... Looked like rust soup



I let it cook for about 30 hrs total. Had to check the anode about every 4 hours or so but the inside of the tank is spotless now.

Check Wall-Mart for the A&H cleaning soda.

Rodger

[3Phase]

Looks great!

I used the Arm&Hammer washing soda. Similar looking insides.

Hey, Rodger! I like the high surface area potato masher anode design! I looks like you caught it just in time before it broke. I let mine go too long the first time and the anode broke off and fell into the tank. I had to get my trusty part-fell-into-a-inaccessible-place-picker-upper-tool to get it out.

I'm staying home for Memorial Day weekend so this is what I'm doing today. This was taken after three minutes using two anodes (two different sized nails, actually) to de-rust the fuel filler neck inside and out



It's already soup! The nails are head down in the electrolyte and I'll keep checking to ensure that the electrolyte doesn't get too low. I'm just going to tilt the tank around so the air bubble inside just below the fuel filler neck will move and allow the electrolyte to contact more of the rusted part of the tank. It should work.

Yes, I'm obsessed with rust....


Regards,

Scott

[latexeses]

Scott,

I stripped the lacquer off a metal coat hanger. That was sort of like the design in the xs650 blog. Their's had two bends--I did three. More's better right?

I jacked the tank up to get the filler pipe as the highest point. I put a bendable soda straw inside the tank with the top of the straw bent so it would be up next to the top of the tank, blew the water out of the straw and slowly filled the neck again. I didn't think of that until about two "checks" into the cook.

When I got finished the wire looked like a rusty piece of .030 gas welding rod. Did the trick though. I couldn't believe that anything that cheap and easy would work that well too.

Rodger

[3Phase]

Scott,

I stripped the lacquer off a metal coat hanger. That was sort of like the design in the xs650 blog. Their's had two bends--I did three. More's better right?

Yes, the more surface area you have for the anode the more current can flow between the anode and the cathode. Within reason, the more current you can get to flow the faster the job will finish.

I burned the laquer off of a couple of coat hangers over the kitchen stove burner -- use pliers to hold the hanger and watch the fingers!

The potato masher style anode worked great for the main, center, part of the tank but it didn't reach far enough to the rear right and left sides of the tank so the area around the fuel petcocks was electrically 'shadowed'. It also wanted to short against the fuel overflow drain pipe and its support stand in the upper middle of the tank.

I bent another coat hanger in half and made it a long, straight, doubled wire and then alternately pointed it to the right and left rear corners of the tank. I changed corners and relocated the ground clamp to match it every couple of hours when it was time to clean the sludge off of the anode. I did the same thing this time using the old tent stake.

I jacked the tank up to get the filler pipe as the highest point. I put a bendable soda straw inside the tank with the top of the straw bent so it would be up next to the top of the tank, blew the water out of the straw and slowly filled the neck again. I didn't think of that until about two "checks" into the cook.

That's a great idea! <smack forehead> Gee! I could have had a V8!

I just burped the tank last time. There is a small hole in the right-hand side of the fuel filler neck tube that will let the air out. It's what makes the gasoline burble all over the place when you fill the tank.

When I got finished the wire looked like a rusty piece of .030 gas welding rod. Did the trick though. I couldn't believe that anything that cheap and easy would work that well too.

Rodger

Yes, it removed a fairly good amount of metal from the old tent stake and nails I used this time. They didn't pit and thin out as drastically as the coat hangers did last time; slightly better steel.

I just started a dilute phosphoric acid soak. It will have to sit for a few hours to remove the the last bits of rust and build up enough phosphates on the bare metal surface inside the tank to keep it from flash rusting before I can fill it with fuel. It's looking pretty good so far!


Regards,

Scott