Rusty Tank Problem?

[BryanMD]

Magical Gas Tank De-Rusting *

(* The actual science is explained at the end)

The things you will need:

1 - rusty gas tank
1 - small container of sodium carbonate (chemical compound = Na2CO3 from pool/spa supplies PH+)
1 - 4amp or better battery charger
1 - average steel bolt approx 3/8 x 1.5
1 - short length of solid 12ga copper wire
2 - quarts Naptha
2 - quarts denatured alcohol

Procedure:

Empty out all the gas and other items in/on the tank and remove the fuel cap. Remove any and all old fuel residue and varnish with a good rinse of the Naptha. Make it petroleum free and then drain and dry.

Using a sock with a handful of small nuts/washers etc,; add a little water into the tank and shake it around inside the gas tank to loosen the big chunks. Rinse with clear water. Repeat: scrub all very well.

In a clean pail dissolve about 3/4 cup* of the sodium carbonate in a gallon of clear regular tap water. When it is dissolved all the way, stir it a bit more! (*based on GL 5+ gallon tank size)

Seal up all but the filler cap opening on the top, pour in the well stirred mix (use a funnel if you’ve had too much coffee).

Fill the tank right to the top with water.

Set the tank securely somewhere and so that the cap opening is the highest part; burp out as much air as possible and keep the tank full for the process.

Strip the insulation off the last 10” or so of the wire and then wrap a series of turns of bare copper wire around the bolt to hold it secure (twist it tight so the bolt won’t fall off). Use something like a paint stirrer with a hole in it to run the wire through and keep it away from the metal tank neck.

Attach the (-) lead of the battery charger to the outer shell of the tank.

Attach the (+) lead to the other end of the copper wire.

Suspend the bolt (through the tank opening) into the solution and turn on the battery charger to a fairly high rate.

An amp or two flowing is good, then wait.

Time to process is ~48 hours and it won’t overdo itself.

Reading back are some things to note:
Compressed air or hair dryer will help dry the tank.
Be sure the suspended wire does NOT touch the tank metal.
Be available to top off the water level (evaporation, etc).
The bolt gets nasty after a day and it won’t hurt at all to clean it now and again to remove the crud.

After a couple of days, remove the leads and discard the bolt.

Drain and rinse the tank well and drag out that sock again and slosh it all around to remove any loose material.

Rinse a few more times until the rinse water seems clear; shake well and then use the alcohol to fetch out the rest of the water. Dry.

Once the tank is dry, you’re all set to put it back into service.

Coating (Kreem, etc) not required.

The Science:

The process by which rust forms is electrochemical in nature so this method employs a reverse current flow in an alkaline bath at a higher voltage to reverse the process at a quicker rate.

There are actually two forms of rust: iron III oxide or red oxide (Fe2O3) and iron II, III oxide or black oxide (Fe3O4) (FeO). Black oxide is the smaller molecule.

The electrolytic process converts red rust to black rust and in the process the black rust becomes weekly bonded to the base metal. The black rust that takes the place of the red rust can be easily wiped, washed, or brushed off leaving a rust free base metal. Any pitting that has occurred will remain, this method will not repair damage, but the pits will be rust free.

This is an alkali process and not acid. So it won’t result in a lot of pits in the steel filled with stray hydrogen ions which would just love to start rusting immediately; instead of this much less active coating of black oxide.

You can’t solve your problems with the same level of thinking that created the problems. –Albert Einstein

Naphtha is commonly sold as Coleman Fuel for camp stoves and lanterns. Denatured alcohol is “rubbing alcohol” sold in drug stores. Usually comes in 70% or 91%, with the rest being water.

Sodium carbonate is WASHING SODA, not baking soda and is sold in the laundry soap section in larger grocery stores.

Naphtha is also sold as charcoal lighting fluid.

Get denatured alcohol in a building supply store like Lowes or Home Depot, or equivalent stores in the UK.

If you have access to a paint shaker you can put about 2 pints of water and a handful of clean gravel the size of peas. Close all openings and shake the tank for a few minutes. Then have a look. If it needs more, rotate the tank and shake some more. Repeat as needed.

When it’s all shiny inside, pour in a quart of alcohol and slosh it around. This will absorb the water.

[Old Fogey]

What type of suppliers sell Naphtha and denatured alcohol?
Hardware stores just stare back at you like you've asked for Randakk's Kriptonite donuts when you ask for naphtha.
Been looking on the web, had no joy there; so where?

[Q]

Naphtha is commonly sold as Coleman Fuel for camp stoves and lanterns. Denatured alcohol is "rubbing alcohol" sold in drug stores. Usually comes in 70% or 91%, with the rest being water.

Q

[ElPiloto]

Sodium carbonate is WASHING SODA, not baking soda and is sold in the laundry soap section in larger grocery stores.

Naptha is also sold as charcoal lighting fluid.

Get denatured alcohol in a building supply store like Lowe's or Home Depot, or equivalent stores in the UK.

If you have access to a paint shaker you can put about 2 pints of water and a handful of clean gravel the size of peas. Close all openings and shake the tank for a few minutes. Then have a look. If it needs more, rotate the tank and shake some more. Repeat as needed.

When it's all shiny inside, pour in a quart of alcohol and slosh it around. This will absorb the water.

If you use Randakk's kryptonite donuts, just set the tan on one for 47 seconds and the rust will be gone.

[DamianBarna]

Hi there, I bought an 82 Aspencade and just had the carbs rebuilt by the local dealer here in NJ. He refused to re-connect the fuel line to the tank because of the rust in the tank. Upon very close visual inspection it seems as though the amount of rust in the tank is minimal. What should I do? It seems like a real ball breaker to remove the tank for such a small coating of rust. Most corrosion seems to be on the fuel strainer and not on the tank walls. On the bottom of the tank there seems to be some small silt waves but as for actual rust in a physical quantity there seems to be little.

Any suggestions?

Thanks,

Damian

[sunnbobb]

Naptha = paint thinner = mineral spirits = BBQ starter=parts cleaning solvent.

[Whiskerfish]

. He refused to re-connect the fuel line to the tank because of the rust in the tank.

Damian

That is a good dealership. many would have hooked it up then charged you again to fix it

removing the tank on these is a lot but it can be done in just a couple of hours. that way you can get a good flush and make sure she is right so you don't foul your carbs. Some guys have had luck with doing flushes with them installed but I would pull it.

[DamianBarna]

I understand, but.....how much rust is too much? Can filtration fix it? Can 2 fuel filters be used? Is there a way to test what comes out to see if this is all just a waste? Has anyone seen fuel cylinders in the trunk or saddle bags? I'm not lazy, just a little afraid to drop the shaft and remove the rear wheel.

Thanks,

Damian from NJ.

[Whiskerfish]

Any filter that will allow flow at the needed rate will allow some rust sediment to get through. The problem with rust is that it continuously breaks down and gets smaller and smaller if exposed to any oxygen. Typically stuff at the bottom of the tank is not the issue as it seldom gets any oxygen. Many advocate a clean tank and always keep it full. Do not put the bike to bed at night unless she is full and you should never have a rust problem. Others advocate a protective coating.

Go to goldwingdocs.com and get the Honda Shop Manual for your bike. Free of charge but I think you have to sign up now. You do not have to remove the shaft just the tire and some remove the final drive (only 3 nuts) some don't. The fender and inner fender and some other small stuff needs to come out also.

[FieldBredSpringer]

Dropping the tank on my GL1000 was the first motorcycle wrenching I ever did. Once you concede that it's not coming out thru the top... it's just a matter of taking the tire/fender/etc off and it comes right out the back.

I'm a nurse (who at 42 had never ridden before) and I figured it out. I would guess that most others on the forum are better equipped than I was to tackle this issue.

I also refinish antiques, and am familiar with both NAPTHA and Denatured Alcohol. NAPTHA is a petroleum distillate like many of the others mentioned, but it is "cleaner" and more refined. It evaporates faster and leaves less residue than mineral spirits and other products mentioned.
This is a pic of the brand I prefer:


Denatured Alcohol is not the same as rubbing alcohol (isopropyl alcohol). Denatured Alcohol is essentially moonshine (ethanol) with a poison (usually methanol) added so it can't be consumed. The cleanest Denatured Alcohol I've used as a shellac solvent seems to be Kleen Strip's S-L-X brand.

It is available at most paint and home improvement stores. It evaporates with the least residue and funky smell of the Denatured Alcohol's I've sprayed.

I didn't mean to get too preachy or technical, just sharing my 2 cents.
-JASON

[DamianBarna]

Thanks for all the great info. I will go to work on removing the tank and attempting to de-rust it. Any caveats to removing the wheel and final drive?

Thanks,

Damian

[fx4fssc]

You will also have to remove the rear brake master cylinder and caliper assembly to be able to get the brake line out of the way. Better to leave them all together, that way you don't have to bleed the brake lines when you reattach the brake hose. The tedious part here is getting into the connection between the brake pedal and the master cylinder plunger, especially with the muffler in your way. Good luck, but the gas tank can be removed, but it is a tight fit.

[DamianBarna]

The bike has been sitting in storage for 8 years. I have already bought all the rebuild parts for the brakes front and back. At this point I really am considering selling it. I am into it for 1400.00 and yesterday I just lost my job.

Anyone looking for a project bike?

Thanks,

Damian

[rogue1000]

I don't know Damian, but since you have bought all the rebuild kits for the brakes and have had the carbs rebuilt, why not just take your time, remove the tank and clean it (not much money, just time), rebuild your brakes, and all else being ok, you will have a 'wing to ride. At the very least, you will something more to sell, and will have added to your skills. At best, you will have a 'wing to ride, the pride of having wrenched on her yourself, a fuel efficient ride, a running bike to sell, and now (aside from looking for another job; very time consuming) time to take some rides.
I hope that something else comes your way soon, good luck, BC

[DamianBarna]

Thanks man. I needed some encouragement. When I bought the bike this Fathers day past, I thought I was doing a good thing. I paid $700.00 for an 82 Aspencade with 30k on her. She belonged to a Blue Knight who died from diabetes and the wife finally felt it needed to be sold. It did not run when I bought it. I was told the throttle cables froze and the brakes needed to be bled, and it needed a new battery. I got it to crank "kinda" and brought it home. I learned the carbs were frozen stiff. I liquid wrenced the carbs loosed them over a 4 day process. I hooked up an iv fuel system and she fired off. Smoking like hell. I decided she was too young to die and jumped in. I removed the cables the choke asbly,the intake the 1&3 carb tophat everything. I could not get those carbs out from the bike. Even the dealer wrestled with the bike but finally did get them out without removing the fairing. It sat in the dealership from June 21 to aug 21 before it got the 6 hours of labor done. They cleaned the carbs installed rebuild kits, air stop valves, and a new accelerator pump, as well as a new airfilter. (I supplied all parts from Partsnmore) They hooked up the carbs toi an iv and it started, smokes 90%less. Now I have to re-assemble everything I took apart and pull the tank. I guess I should replace the radiator hoses too huh. I also bought all the rebuild parts from partsnmore for the front 2 and rear brakes. Hey I guess I have more time now that I lost the job I just got. Had it 8 weeks......And worst part is..they need my services. Can't fugure it out yet, seems like sabotage. Ego's they suck in the workplace.