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Electrolysis Tank

Posted: Fri Jun 13, 2014 6:37 pm
by tekatlarge
I must be getting old but I could have sworn I posted some info here recently about Electrolysis and rust removal.

I looked but it must have been my imagination..

This ties right in with my 2.8 Piston project. To make a long story short the 2.9 short block and crank I recently purchased are getting a good washing and cleaning. The crank had been stored in a unheated building and had a rust coating in places. A main and a couple of rod journals were rusted. In chatting with a friend the other day he suggested I build a Electrolysis Tank. So figuring I couldn't make the crank any worse I set about and built a 15 Gallon electrolysis Tank.

The process I am using is real basic, Non Toxic, and environmentally friendly. I took a 18 gallon blue plastic storage tub I got at the local Fred Meyer. I got 6 pieces of rebar and attached them inside the tub and I added a 2'X2' piece of 1/16' perforated steel sheet located an inch and a half off the bottom of the tub and attached all of them together with a Wire and Lug daisy chain style.

I cut 2 pieces of copper tubing to lay across the top of the tub and be the electrical connection to hang your part from. As I was hanging a crankshaft horizontally I needed something to tie the front and rear of the crank to. The copper tubes were hammered flat on each end so they would set where you put them. I hung the crank with 2 pieces of bare copper 14 gauge solid wire I tied one at the front of the crank and to the copper tube and the rear flange to the other copper tube. I set the crank about 2 inches above the perforated steel and made sure it wasn't touching any of the anode rods.

Next was time to mix the solution. For this process to work correctly you need to use the proper chemicals and use a LOT OF COMMON SENSE. The ingredients Are Simple first is water the second is "Washing Soda" Soda Carbonate. It is very close to baking soda and there is a method to turn baking soda to Washing soda by baking but that is for a later time. Washing Soda can be found in the Laundry section of some stores. The type of Washing Soda I found at Fred Meyer was Arm And Hammer Washing Soda.

Next I Mixed 5 gallons of water and 5 Tablespoons of Washing Soda. and poured the mixture into the tub. ( Formula 1 Tbsp of Washing Soda to each gallon of water.) I put a total of 15 gallons of mix into my 18 Gallon Tub.

Now the tub water level was about 2" above the crank. I brought over my 4 amp battery charger. I hooked the Positive lead of the charger to the anode rods and plate. and the negative lead to the copper tubes holding the crankshaft up.

First thing I noticed after plugging in the charger was the ammeter pegged way past the 4 amps my charger put out. I did some quick figuring and calculating and the tank wanted about 6 amps at 12 volts. Not deterred I found a big ol power resistor and put it in series to limit the current to about 2.5 amps. I then let the whole thing "Cook" undisturbed for 20 hrs. When the tank is working it creates little hydrogen bubbles that float up to the surface along with rust and other metals from the crank. Be careful to unplug your charger and not disconnect any leads while powered. Those little hydrogen bubbles could cause a flash type of fire if you make a spark.

I pulled the shaft at 20 hrs and was amazed as there was no visible rust on the crank so it was rinsed and then dried with a oil coated rag to keep rust from reforming.

Upon a close visual inspection I confirmed the rust removal bath had definitely removed the rust, However every machined surface that had rust on it was stained and had some pitting. I have the crankshaft chucked up in the lathe and I am going to use some polishing techniques on it and then decide if it is serviceable. I hope to decide if I can use this shaft by the end of the weekend.

All of that aside I was impressed by the rust removal it really works and I already have plans to send some really ugly brake backing plates into the tank to see how good this works.

I am working to get my photos sorted out and resized and I am going to put up a page on my site with a bit more detail. I will also post a photo or two here.


Re: Electrolysis Tank

Posted: Sun Jun 15, 2014 11:22 am
by tekatlarge
Follow up:

After cleaning and washing the crank I looked over the journals and noted some discoloration where the rust had been. I threw the crank into the lathe and figured I would buff the discoloration off of the journals. I used my special formula polishing compound and a leather strap and went to work.

I was pleased at the results and where the rust had been on the journals. The rust cleaned up nicely but with magnifying glass You could see some tiny pits caused by the rust. All in all It would have been a good usable crankshaft except for one major factor. The shaft was out of tolerance by about 6 to 7 thousands.

I put a mike on the journals and found to my dismay that the shaft had already 20 thou under. Add about 6 thou of wear on the crank and what I have is a few pounds of scrap!! Cranks can be turned 30 thou under but my own personal requirements say I don't use a shaft that has been turned over 20 thousandths.

So although I wasn't able to use the crank the method to get it to usable with electrolysis was sound. Having a usable crank would have been icing on the cake. I am going to throw some really knarly looking brake backing plates into the tank and see how they do.

Just remember if you decide to do this on your own use common sense and be careful.

Re: Electrolysis Tank

Posted: Mon Jun 16, 2014 10:51 am
by tekatlarge
The results are in on the Tank and it wins hands down. Now if you want to see the completed project with results go here

Enjoy the info.

Re: Electrolysis Tank

Posted: Mon Jun 23, 2014 12:33 pm
by tekatlarge
I was going to post a couple of pictures here showing the brackets but for some odd reason sometimes they show and sometimes they don't. Well I have tried and tried to get these photos to work but I am out of ideas.

So if you want to see the brackets go to my website here at

Re: Electrolysis Tank

Posted: Fri Jun 27, 2014 10:52 am
by tekatlarge
Here we go last couple of Pics on the Electrolysis Tank. This last part the Sickle Bar has been done. I am still impressed with the overall operation of the tank. I have however run into a slight problem.. It seems my steel screen idea wasn't as good an idea as I thought. I figured to get the junk off the screen by just scraping the crud to the ends where there is room for the sediment to fall tom the bottom of the tank!

It was a good idea in theory. The problem is I forgot about the rust attaching to the steel anodes. First try to clean off was less than impressive. I finally fished the plate out of the tank and cleaned it with a wire brush. The plate shows a lot of consumption of the steel. I may look into using some carbon fiber sheets I have heard works really well. All in all not bad for less than $50.00.