Possible rust remover for gas tank
 

I have used this system for rust remover a lot! works great!!!

but I was wondering if it might be used to remove the rust from inside a Model A gas tank? Let me know what you think?

Re: Possible rust remover for gas tank
 

I have been told that method is "line of sight". If that is true, what do you do about the baffles??

Re: Possible rust remover for gas tank
 

This has been covered several times before. A search will find a number of posts on electrolysis removing rust from iron and steel items, including gas tanks.
Rusty Nelson

Re: Possible rust remover for gas tank
 

would oxalic acid be useful for this?

Re: Possible rust remover for gas tank
 

X2-post#2 I tried electrolytic and was not happy with the outcome :-(
Inside areas away from rod did not do so well . 11 gals of evaporust is what
I would use but $$$. It is reusable,anyone want to go in halves ?

Re: Possible rust remover for gas tank
 

evaporust is well worth the money versus the labor of pulling and repainting the tank

Re: Possible rust remover for gas tank
 

From my perspective, the $150 for ten gallons of Evaporust is the cheaper portion. Unless you have a way to completely coat the interior of the tank, it will only continue to rust. I don't know how many tanks we have cut open to find the sloshing process did not cover all the areas of the tank. These bare areas continued to rust even though the tank was sloshed. Therefore you need to purchase ten-plus gallons of sealer to do the job. The last I checked, sealer was over $125.00 a gallon! ;)

Re: Possible rust remover for gas tank
 

Fill the tank with a 6:1 mixture of water and molasses and leave it for 2 weeks. Then flush out thoroughly with water until all traces of molasses are gone. Don't put gas in until interior is dry. You will be surprised how effective this is at removing all rust. It costs almost nothing and there are no line-of-sight or safety issues.

Re: Possible rust remover for gas tank
 

Nice to hear. Are you going to cut the head open to view the success?

I have even a better idea to determine if indeed folklore. Someone needs to cut open a gas tank to document the internal condition, then weld the tank together again (maybe tack weld and then temporarily seal the cracks). Next use the electrolysis methods for however long is deemed appropriate and then cut the tank open again to verify the results.

Re: Possible rust remover for gas tank
 

They make cameras on a rope type devices now.

Re: Possible rust remover for gas tank
 

If the tank is removed for restoration, like many are, why not stand the tank on end and fill the tank about half full of rust remover (Evaporust or whatever). It will only take about 5 gallons of rust remover to do almost all the tank if you flip the tank after letting the solution do its work on the first half of the tank. There might be a very slight amount of the tank that might not get derusted in the center. That would save some serious $$.
Rusty Nelson

Re: Possible rust remover for gas tank
 

I use Arm and Hammer WASHING soda ! I have also used Vinegar Both worked well.

Re: Possible rust remover for gas tank
 

Harbor Freight is up to $30 a gallon for rust remover. I was in Menards yesterday to buy paint stripper and noticed they sell rust remover for $20 a gallon.

Re: Possible rust remover for gas tank
 

Whatever you use to clean, derust, or coat a tank it might be worth your time to rig a motor and drive to make a rotisserie that automatically inverts the tank end-over-end (or whatever) while you sleep or do something else. I have seen a belt-driven tire (on a fixed wheel and hub) to which a gas tank can be strapped with a belt drive and a gear driven one. Sharp crushed glass is one of the mechanical means I have seen being used to clean internal tank surfaces (newer gas tanks, not Model A). The volume of solution required with rotation may be much lower, but then you may run into the limits of the chemical conversion capacity of whatever you are using.

I have gotten good results with new Evaporust on some small rusted things however its capacity is very low and because it is made of organic chemicals reuse is usually out of the question since it is degraded by bacteria very quickly and seems to turn acidic which can further damage what you are trying to preserve if you trade longer time in the solution for reduced capacity.

Re: Possible rust remover for gas tank
 

Phosphoric Acid might be better than any other acidic solutions for gas tank work. The reaction is not fast - but it does work.

I normally use Kleen Strip "Prep & Etch" on all my electrolytically derusted goodies. The electrolytic method leaves Ferric Oxide (magnetite Fe304) which is a black oxide of iron - this ferric oxide is quick to revert back to ferrous oxide (red rust Fe203) hence a need to use SOMETHING prior to painting.

Prep & Etch fills this gap for me. But it works not only on Ferric oxide, but also Ferrous Oxide in the reaction...

2 H3PO4 + Fe2O3 → 2 FePO4 + 3 H2O

Prep & Etch comes as a solution, gallon jugs run about $15, and is a contact sort of chemical reaction meaning one could set up a rotisserie arrangement.

When you're done you can then pour off the excess Prep & Etch, rinse out the tank with water, dry quickly, and then coat in a reasonable amount of time the passivated surface created with your interior coating of choice.

Joe K

Re: Possible rust remover for gas tank
 

Just curious as to how many gas tanks you have used this method on?

Re: Possible rust remover for gas tank
 

I've used the etch and prep many times. Not on gas tanks. But lots of other parts. Works great. I wonder how the eloctrolosis would do on a block. Would it hurt the babbit?

Re: Possible rust remover for gas tank
 

NOT recommending Electrolytic on a gas tank for the "line of sight" reasons mentioned. (I see others may have taken that meaning away from my earlier post. ) But the P&E is good stuff. And I see no reason why it shouldn't work all by itself.

In fact, thinking this out further, if one is going to fill the tank with nuts & bolts and do a tumble cleaning (which I have done) why not put the prep & etch solution in at the same time?

Get that mechanical removal action at the same time as a chemical reaction?

I'm ALWAYS open to suggestions - or critiques.

Joe K

Re: Possible rust remover for gas tank
 

I am really interesting in knowing if electrolysis is "light of sight" or a myth - maybe the Myth Busters program?

John

Re: Possible rust remover for gas tank
 

Oh, no question it is line of sight. But I will counter that in those regions that are "around the corner" electrolysis still occurs, but just not as fast. There may even be a point in the "back corner" where electrolysis doesn't occur fast enough to counter the forward oxidation of iron. And there may be some point or line in the bath where the two forces, oxidation and electro re-composition, just about match.

Another good reason to use Prep & Etch after removing items from the bath. It kind of the extra "shove" that puts iron into that desireable Fe304 oxidation state. Or it's phosphated equivalent. (see reaction above.)

Joe K