Electrolysis for Rust Removal

After reading up on electrolysis for rust removal, I thought I would give it a try on the XS400 tank. Here are some pictures of the setup and how it worked. I have to add that this is extremely simple to do compared to working with the acid I used on my Seca tank.

All you need is a bucket, battery charger and the Arm & Hammer Washing Soda.

Here is the Sodium Carbonate (Arm & Hammer Washing Soda) to make plain water into an electrolyte. Just use 1 tablespoon per gallon of water.


Here is the sacrificial anode. Just a piece of threaded rod and a cap from a can of spray paint trimmed a little to fit the tank opening. This holds the rod away from the sides of the tank.


Here is the setup in operation. Fill the tank with the electrolyte solution and connect the positive clamp of a battery charger to the threaded rod and the negative clamp to the tank. It is important that the threaded rod does not come in contact with the sides of the tank. What is happening is any rust, paint, crud, sludge picks up a negative charge and then becomes attracted to the positively charged threaded rod. The rust and crud slowly start to move to the threaded rod. A lot of the material sticks to the rod and a lot of it settles to the bottom of the tank where it comes out when you pour out the tank when finished. Keep in mind that the process produces small amounts of oxygen and hydrogen, so have some ventilation.


Here is what it removed from the inside of the tank. The dried rust on the workbench is from knocking off the rod after about 4 hours. I ended up leaving it going overnight. Notice that the rod collected sludge in addition to the rust.


This bucket contains the electrolyte solution after pouring it out of the tank. In the bottom is a layer of sludge that the process loosened from the tank sides and poured out when I drained the tank.

 

Works great for getting up and residue stuck to the rust doesn't it?
That how I got the remains of my failed molasses attempt
Nice job on the anode, I made a plug out of hard foam, that looks more stable...

 

When I was gonna clean my tank, I read up on the electrolysis process. Read accounts of burning holes and such.......I just used chemicals LOL! Looks like it worked pretty good for you...

skillet

 

Gadfrey. What's it look like inside?

I'd go back and flush it with phosphoric acid now.

 

There's no need to flush with acid. The inside of the tank is spotless. As soon as I poured out the electrolyte, I blew out with compressed air and then coated the inside with MMO as I won't be filling it with gas for some time. I'm still going thru the things I need to do to start the motor for the first time.

I can post pictures of the inside of the tank hopefully tomorrow. The tank is at a buddy's this weekend who is going to try to pull out that huge dent on the left side of with one of those stud welders.

 

Ah, good ol' Mystery oil. Love the stuff.

 

cturek,

Did you electrical tape the other end or no need to since it appears that it is at a right angle & the rod was suspended inside without touching sides or bottom.....

Just wondering......

Great job...

 

cturek,

How long was the anode rod & was it a 90 degree angle....how did you ensure that it didnt touch the tank on the inside ???

Just curious........I was about to use your method.....looks like it worked well....

5ofakind

 

Eeek! That scares the crap out of me.

 

I've done two tanks like that using regualr table salt instead of washing soda. It worked fairly well and cleaned out all the rust in the tank. I used a short piece of 1/2" rebar for the rod in the tank mounted on a rubber drain plug from a sink that fit tightly in the fill hole. With a 10 amp charger, nike took pretty much the entire day to clean it out completely.
I then used rubbing alcohol (evapoates well) to clean out the tank and blew it dry inside with a blow driyer before refilling it with gas. Now as long as the tank is full when I park it, I don't have a rust problem.
The main reason there is rust inside a tank is because they are left mostly empty or drained completely before sitting for extended periods of time. Always keep the tank full to prevent rust is the best method.

 

Hey.. Nice job.. Gonna give that a go on some of the other parts I have that are rusted up.

I think the trick here is to make sure you DON'T switch on the car charger until after you are CERTAIN your electrode is NOT touching any of the sides.. (If it is, you're likely to burn a hole!)

 

take a meter check to make sure its not touching also if its touching the meter on the charger will peg and the safety should pop the charger off. if you use a low amp charger it shouldnt burn a hole anyhow. just make sure you have the termanals hooked up properly. if you hook them up backwards it will bont the rust to the tank instead of the anode

 

here is an article on how to do it

There is a simple way of forcing the rust to plate a sacrificial electrode (steel or iron), but the process can take quite some time. Needed are a battery charger (a weak one will do) or other power-source (an old step-down power brick for an discarded electrical device will work if you slap a couple alligator clips on the leads), a piece of bare mild steel or iron as large as you can find that will still fit through the gas-cap opening without touching anything, water and washing soda (Arm & Hammer brand will do nicely).

Remove the fuel-tank sender assembly, the petcock, the gas cap assembly, and any other removable items from the gas tank. Seal up all the holes in the tank except the gas cap filler hole (using plastic or rubber -- do not use aluminum), so that it's water-tight.

Mix 1 Tablespoon of washing soda per gallon of water and fill the tank with the mixture (note: stronger will not accelerate the process, so don't go overboard).

Without plugging it into the wall, connect the battery charger or other power source as follows: positive to the mild steel or iron part, and the ground to the gas tank itself (such as to a screw that normally holds in the petcock). You need to make sure that the lead to the mild steel or iron part will not touch the tank's metal, so insulated wiring is smart.

Figure out how to support the steel or iron part in the tank without touching the sides or bottom, and without forming a grounding circuit to the body of the tank (a bit of nylon mesh attached to a plastic ring too large to pass through the opening of the tank will work wonderfully -- or some nylon twine tied off to something above the tank). Lower the metal into the tank and double check that it's not touching anything except the solution.

Now you're ready to energize the system -- plug in the charger. How long the process will take will vary with three factors: the amount of surface area of the metal piece being suspended into the solution, the amount of power running through the solution, and how much rust we're dealing with here. In particularly bad cases, you may have to drain/rinse out the tank every 12 hours, wipe down the metal, then start over. If the mixture looks like a dark red stew, definitely time to change it. You will also need to top off the mixture with additional water if the level falls, as the process cooks off water (electrically rips it apart).

 

This technique also works wonders on small parts. I used electrolysis to remove the rust from my car's extremely frozen emergency brake lever after 4 days in PB Blaster did nothing.

 

I'm trying this method for my tank as well but can't seem to get it to work. I have a trickle charger that I was using, but I felt like the amperage might be too low, so I borrowed a friend's charger. Unfortunately, it's one of those "smart" chargers that won't work if it detects that it's hooked up incorrectly. So I hooked it to my car battery, then had leads coming from the battery terminals to the tank. Still, no real results, even after sitting overnight. I must be doing something wrong; it looks like it worked wonders for you.

 

First, I definitely would NOT connect a car battery for the power source. If you accidentally shorted out, you would have some serious safety issues. The high current from the battery would, if your lucky, only weld the leads to the tank.

The power source really should be a battery charger capable of putting out 10 amps. You also need it's built in safety circuit.

Do you have the polarity connected correctly?

 

First, I definitely would NOT connect a car battery for the power source. If you accidentally shorted out, you would have some serious safety issues. The high current from the battery would, if your lucky, only weld the leads to the tank.

The power source really should be a battery charger capable of putting out 10 amps. You also need it's built in safety circuit.

Do you have the polarity connected correctly?

 

I'm in the process of "electrocuting" my tank right now and I'm wondering about how long I should let it go. I've had it running on the 2 amp setting for close to three hours and there is definitely a lot of activity and junk collecting in the fuel cap hole (which is open).

Is there any value to emptying it part way through and adding a fresh water/sodium carbonate solution?

Is it possible to do any damage by letting it go too long?

Thanks!

 

Since I posted I've been searching the forum for info about how long people have let this process go. I'm just laughing now because I've read everything from 4 hours to 10 days with multiple rinses and anode scrapes.

Maybe I should start a poll...

 

I ran two tanks of solution to do mine. About 1 hour on each tank full did the trick with a 10 amp charger.

 

Thanks, PainterD. I was also wondering about amperage so I'm glad you specified that. I was a little afraid of using the 10 amp setting so I've had mine going at 2 amps since yesterday afternoon. I'm going to empty it this morning and see where I'm at. I'll post a report later.

 

OK, here's the report on my electrolytic tank cleaning experience.

I used the Arm & Hammer Washing Soda - which was not easy to find (Ace Hardware) - at a concentration of 1 tablespoon per gallon.

I used 3 strands of heavy fencing-type wire twisted together with a very large wire nut on the end. I made this anode extra long and then bent it so that I could attach it a stud in my garage wall with a couple of electrical staples. I also slid a section of the outer insulation off of a piece of Romex over the end to insulate it where it was stapled and also where it entered the tank.

I wasn't too sure about running my battery charger at the full 10 amp setting so I had it running at 2 amps. This took three rounds of about 8-12 hours each. I dumped it, checked it out, scraped the anode, and refilled with fresh solution each time.

I'm not sure that absolutely ALL of the rust was gone even at that point. There seemed to be a few little pesky spots - specks really - that still looked rusty. It was pretty dang good, though. As mentioned in other posts, it was blackened in the places where the rust had been.

I rinsed it with water, then quickly with some POR-15 Marine Clean solution mixed with warm water at 5:1 and sloshed that around for about 15 minutes. Then I rinsed again a couple of times with clean water, drained it, and dried it with a blow dryer.

I then went with Fitz's Seafoam, motor oil, and gas cocktail and sloshed it around. I had to leave town at that point, so I just let it sit with that solution in it for about 10 hours. I dumped it out when I got home and it was an interesting sort of caramel/butterscotchy color. Then rinsed with more gas and oil, then finally with gas oil, and Marvel Mystery Oil. Drained everything I could, then used a rag to wick up the rest.

It looked pretty decent, though not like brand new metal as you acid-lovers have described. I think I'm in good shape, though.

 

You should have removed all the rust that would've came lose and found it's way to the gas filter or the carbs. Looks like you have the problem dealt with even though it's not like new metal. Good job!

 

That's kind of what I thought, too. Plus I've got a brand new filter on my fully rebuilt petcock and an inline filter, so that should catch most anything that might cause problems.

 

Idid this too my tank a week ago.it worked great,better then i expected..only thing that was unexpeceted is that the tape i used too hold my node in peeled y clear coat off.no problem though i had planed on repainting it any way. 8)

 

I'm getting ready to try this method but am having trouble finding the washing soda. We have lots of oxiclean though and it has the sodium carbonate in it. Anyone tried this? I really don't want to mess up my tanks as it has some other ingredients in it also.

 

dang, thats impressive - after pics of the inside will be interesting to see

 

I did, too. Finally found it at Ace hardware. If they don't have it on hand they'll probably order it in for you.

Works good in the wash, as well. Add a half a cup to a load with greasy shop clothes and it really makes a difference.

 

Couldn't find it locally so I got it from amazon (ace hardware) shipped for $8. Both local Ace hardware stores never even offered to order it.

 

Thats redic. Just lazyness on their part.

Glad you got a hold of it some way though.

 

I'm wrapping my project with this up today/tomorrow. Ran it once, on 2 amps for a couple of days. Flushed everything really well, and refilled with fresh electrolyte and ran it again since last night. Should be the last time. How are people drying these out instead of filling/coating with gas or oil? I was thinking about the shop vac with the hose on the blow side, and a reducer through the filler hole, but any other ideas would be appreciated.

 

As an afterthought to the last post, I left the petcock and the sending unit in place, because I am going to re-build the petcock, and the sending unit was a mess, and both came out great. The sending unit moves completely freely now, and sure as hell looks better also!!

 

I have a very old 6amp 6v/12v battery charger that I've been trying to use on this topic. I ran it yesterday set on 12v for about 12 hours and got absolutely no results. I may need to buy a new battery charger as I'm not 100% about its actual output. Wouldn't 12 hours at 6amp/12v give me some sort of results?

 

At 6 amps you would begin to see results within a few minutes (the electrolyte bubbling as hydrogen is released). Describe the rest of your setup. Was the part you had in the tank degreased throughly?

 

Wow I'm glad this topic got necro'ed, I'm gonna get out of bed now & rig up some old bits of Honda to a battery charger overnight & see what happens

 

Anode touching the tank possibly?

 

I like it a lot Only got a couple of rusted old inlet valves as a test piece sat in half a milk carton, with an old breaker bar as anode, but it's fizzing away nicely at 0.75A which I'd expect due to smaller surface area.

Might not leave it overnight considering how well it was fizzing, maybe check in a couple of hours or before I go to sleep... Looks like a fun way to rescue parts.

EDIT-: anode touching his tank would blow the fuse if it's the sort of charger I'm thinking of...

 

I have about 12" threaded steel rod recently bought at a hardware store. Not sure if it was ever greased but I know I didn't degrease it. Originally I had it ran through a large rubber stopper with a metal washer and nut on each side of the stooper. It was nice and snug in the gas cap opening. I thought maybe the rubber stopper was grounding it somehow so I switched to a plastic cut-off paint can lid like the 1st pictures posted on this thread. My rod isn't touching anywhere inside the tank, just in the distilled water and Arm&Hammer mixture.

 

well your kind of lucky it didn't work, the cap has to be loose or it'll pop off.
check the connection to the tank, you should see something in a minute or two

 

Yeah I thought about that after the fact Polock. I'm going with loose from now on (in this regard anyway).
Now I tried something different. I put my rod in a ceramic coated tray like an old doctors instrument tray. I rested my rod on a couple of rubber tubes so it wouldn't contact the tray and hooked-up my charger (neg. to tray, pos. to rod). I never saw any "activity" after an hour. Could it be the distilled water? Are y'all using plain tap water? I mean with a tablespoon of Arm & Hammer per gallon of water of course.

 

The water won't matter. I use tap water, but once you put the washing soda in distilled water isn't distilled anymore. You are using washing soda and not baking soda, aren't you? If you used the bicarb it won't work as fast since the solution isn't as alkaline as it is with the washing soda (sodium carbonate).

Since we're talking about an electrolyte that costs pennies to make just dump the tank out and remix using tap water. Personally I use a 5% solution instead of the 1% the first post calls for, especially if the part is particularly rusty (more than just light surface rust).

 

hold on there, the - black lead goes on the tank, the + red lead goes on the threaded rod. the - black can go anywhere on the outside of the tank, just so it makes a good connection.
think of your rod like a florescent tube, the process is going to work faster where the light would be brightest and slower in the shadows, so your going to want to move the rod around when the first area is done.
it's best to keep the tank almost full, the bubbles are hydrogen if you get a spark in them it might pop a little flame, no big deal but you don't want a quarter tank of them. the bubble goo won't hurt the paint at all if it runs over

 

Glad that you caught that. With the leads reversed he was plating the tank with steel from the threaded rod (very, very slowly, and no...it would not have worked to renew the tank).

 

Yeah I have it hooked-up correctly. Positive (red) to rod, and Negative (black) to tank. Tank is almost completely full with mixture. Yeah I have washing soda. I bought the exact box shown at the beginning of this thread. I'm gonna dump out the mixture and start again when I get home. I'm really starting to think it's my weak-arse charger more than anything else. Sorta off topic but what size amp charger are y'all using on this?

 

The amount of wash soda and the size of the rod determines the current draw more than the charger but a newer charger is always nice.
Double up on the soda.

 

Is the charger definitely working? (test lamp?)

I did some experiments last night with shower gel (because it was all I had with sodium in it!) and a couple of old inlet valves from a scrap Honda head & the results were amazing

I'm currently (pun intended) attempting a copper plating experiment too as I noticed some copper from the charger wire transferred to the anode when I did the valves.

 

It finally worked! I started anew last night and used tap water and increased the washing soda from 1 tbsp per gallon to 5 tbsp per gallon. Probably a little overkill but it worked. Thanks everyone!