Gas tank rust

[patriotcommercial]

My gas tank is mostly clean but has a small amount of rust on each side on the bottom.  When you look in the filler it looks clean, but on the very bottom at the sides there is some rust.  I plan to remove it using electrolysis , I have done this several times and it works well with no harmfull chemicals.

My question is this: I want to attempt to seal just the bottoms after cleaning.  I think I will pour some sealer using a funnel and a rubber hose down into the bottoms.  Then rock the tank front to back and side to side very slightly , just not get the top.

I like the original Finnish on the hump when you look in.

Has anyone tried this partial sealing the bottoms ?

[Steve Swan]

never heard partial sealing tank a good idea.  while you are emptying washing soda solution from the tank, have a garden hose running to fill the tank to keep it from flash rusting.  immediatle upon flushing, then dry with mek/compressed air and put some oil in tank, rotate tank, will store fine til ready to fill with gas.  rotate occasionally to keep oil film thick.  i've done this w/ many tanks i've put in to storage or in to service; works well either way.  i always try to avoid using any liner products unless the tank was severely rusted.

[patriotcommercial]

Cleaning underway.  It is a amzing how much rust this method will take out of a tank that looks only slightly rusted.  First step is to mix up one cup Arm & Hammer washing soda.  I use one cup of washing soda in a 5 gallon pail and fill the tank using a measuring cup.  Then I use a piece of sheet metal that I ruff up on my wire wheel.  Insert into the tank a piece of PVC pipe with holes cut into it so the metal is in the liquid be not touching the tank.  Then I attach the negative clamp of my battery charger to the tank and the positive clamp to the metal piece.  I turn off the charger and remove the metal and scrap of the rust every few hours.  I will change the liquid about every 24 hours.  I expect this tank will take two or three days.

[Steve Swan]

i like that pvc tube you use to keep the cathode from touching the tank.

[UK Pete]

i have used this method, it took about 24 hrs,and worked a treat, however be aware of the harmful FLAMMABLE!!!! gases that come from the tank during the process, and as mentioned before be ready for flash rusting it happens almost immediately
pete

[kp]

Does this process clean the tank and/or replace metal lost through corrosion

[Steve Swan]

removes rust only.

[patriotcommercial]

When the tank is clean, I dump out the solution and rinse it. 

Then I put about a half dozen small rags in the tank.  I use compressed air to blow the rags around the inside.  That gets a lot of the water out.  You be sure to count how many rags you put in so you get them all out. 

Then I go back in with another towel or chamois and move it around with a cloths hanger straightened out. 

Then within a few minutes of the draining I dump two small containers of rubbing alcohol in and slosh around.  The alcohol absorbs the water.  Drain the alcohol, and the use the heat gun or the hair dryer.

There may be a small amount of flash rust.  The best part of the process is nothing is used that causes paint damage.

Then hit it with WD 40.

[Steve Swan]

after i've flushed the tank, i use MEK and a heat gun to get rid of water, then i also use WD40 to stop flash rust. 

[1941wld]

Why don't you just use a cleating agent. This is 2014. It will not hurt paint, rubber, or chrome. Just pour it in and wash it out. White metal. Poof. Evapo-Rust


http://shop.advanceautoparts.com/p/evapo-rust-evapo-rust-er012/10181905-p?cm_mmc=ACQ-_-Google-_-GPLA-_-10181905&ci_src=17588969&ci_sku=10181905&ci_gpa=pla_with_promotion&ci_kw=&iv_=__iv_p_1_x_pla_with_promotion_y_6201684_f_online_o_10181905_z_US_i_en_j_71043005542_s__n_g_t__d_c_v__vi__&gclid=CMTo8oTS8MACFc1i7AodNwMAqw#utm_source=acq&utm_medium=google&utm_campaign=gpla&utm_content=10181905

[patriotcommercial]

I use evaporust all the time.  I have four number 8 bolts soaking in it as I right this.  I have used evaporust on tanks before. 

The first issues is that with evaporust you must submerge the rust and let it soak.  The ad you showed is for $22 for a gallon.  You will need almost 100 dollars of evaporust to fill the tank.

Second issue is that the evaporust turn the rust black and neutralized it.  You need to removed the black stuff off the surface, you can rinse and flush but to get it really clean you must touch the surface with a rag or other material. 

I use brass wool or scotch rite on bolts or other parts to get the black rust off the bolts under a stream of running water.

Evaporust is amazing stuff, very good, I use it all the time.  I even invent crazy containers to hold part to submerged the parts.  I use PVC pipes a lot to fit pieces in.

I don't have an efficient technique to wash the inside of the tank and remove the black residue.

Any body have a technique

[1941wld]

I find that if you leave the part in too long I get the black coating. When I use it in for a shorter time period I do not get the black coating.

[Steve Swan]

Put a mix of 50 3/8" and 1/2" nuts in tank.  Wrap the tank in 3" foam layers, use duct tape to hold the foam in place. Put this setup in the clothes dryer with no heat; dryer acts as a tumbler.  Use foam blocks as needed to support tank so it doesn't flop in dryer.  Run for one cycle; repeat as necessary.  

A few years back, i cleaned (using electrolysis) the tank on 2157; worst rust I've seen to date on a tank i felt could be saved.   When electrolysis complete, had 2 pin holes on top of tank (not because of electrolysis, but because of severe rust from sitting in high humidity environment for 17 years with lid closed, 1" gas that had turned rock hard.)  

When electrolysis was complete, had black scale everywhere on inside, would come off easily manually with direct contact only, so i got the nut 'n dryer idea, which removed the scale extremely well.  

Enclosed pic of cap is what was all over inside tank.

[patriotcommercial]

I have seen the dryer use on youtube.  The guy doing it used comforters from the linen closed and stuffed them around tank.  I am wondering how it would work if you filled the tank with green pyramids from Eastwood.  I put small parts in a bullet shell vibrator with geen pyramids and they clean the parts very well.  Green pyramids are small plastic pieces in the shape of a pyramid the have sharp edges on the plastic that clean but don't damage.

[Steve Swan]

I have seen the dryer use on youtube.  The guy doing it used comforters from the linen closed and stuffed them around tank.  I am wondering how it would work if you filled the tank with green pyramids from Eastwood.  I put small parts in a bullet shell vibrator with geen pyramids and they clean the parts very well.  Green pyramids are small plastic pieces in the shape of a pyramid the have sharp edges on the plastic that clean but don't damage.

Green pyramids... Worth a try !  Please report back if you use them !