View Full Version : rust removal electrolysis

Brett Hurt
03-11-2011, 12:18 PM
I tried this and I did something wrong I used Arm & Hammer super washing soda and a stainless steel electrode and the battery charger. Iam derusting some misc-box disk that are 27in. dia. So what did I do wrong Brett

03-11-2011, 12:25 PM
What happened? It is a simple process, and relatively trouble free.

It does take time to be effective depending on the amount of washing soda used and the current applied. Ideally, you should be seeing some bubbles rising from the part, if not, increase the strength of the solution or current.

Stainless steel is not recommended as an electrode as it can produce a dangerous byproduct. Use a mild steel electrode, the larger the better. You will need to remove it and clean it of the crud generated from time to time.

J Harp
03-11-2011, 12:33 PM
Check the polarity of your setup. The Positive lead from the charger goes to the stainless electrode, and the negative to the part you want to derust.

03-11-2011, 01:34 PM
At 27 in diameter your going to need a serious electrode. the process really works best in a Line of sight mode, IE: a clear path between the electrode and your part (without them touching of course). Time and power will also play a big part here, don't hesitate to leave it go for several days, occasionally clean your electrode (I always rinsed, wire brushed, and rinsed again.)

As mentioned before Stainless prolly isn't the best choice, when I had large parts I used strapping from the hardware store to make a cage, it's easy to cut and bolt sections together.

03-11-2011, 02:40 PM
Stainless steel, as has been noted in other threads is a very bad choice. It does produce a hazardous byproduct. Many electrodes wired in parallel surrounding the piece to be cleaned will be superior to a single electrode.

03-11-2011, 02:56 PM
As it has been said about the electrodes Do not use stainless steel. Also the more electrodes the better, make sure you have the correct polarity as you can rust items the other way.

Lots of electrodes rebar is my choice lasts with cleaning a long time

Working normally washing soda

After about 12 hours of use before cleaning

After power washing, ready for reuse.

You can bend the with heat into an L shape and place the item on wood or bricks to keep it off the electrodes as the go across the bottom to give omni directional cleaning. The electro-chemical reaction is sort of line of site. As in the one photo with the white and rust colored foam.

03-11-2011, 03:07 PM
I was hoping to see a picture of the tire hub as well after you finished!

03-11-2011, 03:14 PM
This was using the fence type reinforcing material for concrete work

I cut to fit the container and bent the ends up to clear the liquid,then connected it to the battery charger at multi locations. The container is a sturdy mud boat.

The problem with the reinforcing material the small dia. slows the reaction, and it will also slow down as the electrodes get gunked up

Looking to do two wheels at a time, I forgot that water is heavy and would push out the sides.

After removing the water and wheels, took about a week with the lid on and in the sun to return to normal.

I found a nice water/feed tub about 50 gallons made out of expanded polyethylene plastic @ Tractor supply very sturdy and I'm putting a drain in one end and made up a flat cart to move it when filled.

You only need enough water to cover the item, but lots of electrodes.
Since your discs are light in weight and float, Place a couple of pointed dowels in a couple of furing strips weight them bown with rocks patio stone or bricks not metal. Do the same thing on the topside, to keep tit under the water. Then flip over to do both sides. If you have a bunch to do rig up some electrode to go over the topside and you should be able to do both sides at the same time.

03-11-2011, 03:22 PM
I was hoping to see a picture of the tire hub as well after you finished!

Here is the start of one


Here is the rim, inside and out sides. No mind you you could get them cleaner with a change of fresh electrolyte clean electrodes and a redo.
These were good enough to be primed and painted then filled with concrete after welding in a plate and eye bolt for the carport anchors.

03-11-2011, 03:32 PM



Here what they look like finished and installed

Dr Stan
03-11-2011, 04:33 PM
I used the process to remove surface rust from the table & knee of the Fray mill I'm rebuilding and it worked great. I too used rebar for the electrode as its easily available and cheap and for the tank I used a 57 gallon Rubbermaid tote. What I really like is that it just strips the rust and you can start the process and just leave it alone for a couple of days and come back to a nice an rust free part.

03-11-2011, 05:05 PM
Hey PTSideshow.....Try POR15 paint....you will NOT believe
how well this stuff works...i sandblast all my parts first...
but you can use all other methods (wirebrush,chemical)
to prep it.......Dean

I saw some info that someone bend a steel part and the POR stayed on....so i took a piece that we painted and brought it out side and hit it with a hammer....NO chips....really amazing

03-11-2011, 05:20 PM
Hey PTSideshow.....Try POR15 paint....you will NOT believe
how well this stuff works...i sandblast all my parts first...
but you can use all other methods (wirebrush,chemical)
to prep it.......Dean

Tried it 15 years ago way to expensive, wasn't that impressed with it and you still have to clean off the curd etc before painting. Put the rims in the tubs and come back in a day or so. A lot less work than wire brushing, and if I was in a hurry I would have media blasted them. Besides it was a learning deal for some engines that I have to clean.

Plus when the local lumber yard went out of business, I purchased a dozen cases of primer and rattle can colors!

03-11-2011, 05:22 PM
I use the generic Oxi-clean stuff from the grocery store and am currently de-rusting the base from a Delta Unisaw. Works great. A suggestion for the sacrificial metal to use is an old brake rotor. It is cheap, compact with a lot of surface area and seems to work like a champ. I hook the positive to it and put the charger on the 12Amp setting and it will clear parts in about 2-3 hours.

03-11-2011, 08:33 PM
Arm and hammer proportion to gallon water Mixture is important to how good it works.

I use 1 tablespoon per gallon, it feels greasy in your hand when you stick your hand into it.

It helps the conductivity I suppose? I used a livestock watering tank and a dc welder on my car fenders and big parts. VERY dangerous?? a calculated risk.

A http://www.metalmeet.com/ forum deal came up on this, chelating rust- with mollasses... HOW it worked and all came to light, along with the industrial patent on a derusting mixture made from it..