Rusty Tank Problem?
Posted: Mon Jan 14, 2008 3:00 pm
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.
(* 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.