Rust removal experiment

drcoastline · 07:34 AM

Some of you may know this method already but, I thought I would post the electrolosis method of rust removal for those unaware. I need to remove some rust from a few larger pieces of my car. Such as my sway bars and a few pieces of engine tin I want to repaint. I dreaded the thought of spending hours with a wire wheel in my grinder and spraying on rust converter and waiting or having the pieces blasted and potentially damaged. So I went looking for an easier method. I came across a few videos on you tube for "electrolitic rust removal" or electrolisis.

I prerformed the experiment yesterday on a pully cover I had laying around to see how it worked. The process is simple. You need 1Tbl.sp. washing soda per 1Gal of water. Arm and Hammer washing soda is availalbe at your local supermarket. I paid $2.99 for a box. For 5 Gallons of water you will need 1/3 cup Washing Soda and a power source. I used a 12v float charger that I bought from Harbor Freight for about $6.00. A battery charger will also work. A piece of sacrifical metal (rebar, sheet metal, old lawn mower blade, etc.) and some wire. I used an old coat hanger.

Put the washing soda in the water and stir. Connect the poisitive lead (red) to the sacrifical metal. Clean a spot so you have a good connection. Connect the negative lead (black) to the part you wish to de-rust again clean a spot. Think battery terminal connections. I threaded a piece of uncoated coat hanger through a hole in the bracket and the connected the lead to that so the clip from the charger was not submerged. Place the part in the bucket. Place the sacricifial metal in the bucket (do not allow the parts to touch). Plug in the power source and go do something else for a while.

A NOTE OF CAUTION: This process creates Hydrogen which is falmable so do this in a well ventelated area and do not smkoe or place near an open flame. The hydrogen may ignite.

I stared this process yetserday at about 3PM. I took the part out this morning at about 10AM.

Here is how it cam out.

The pully cover prior to de-rusting

The solution about 20 minutes into the process. Note the rust starting to accumulate on the right side of the photo.

Soultion at 10AM this moring.

Pully cover and sacrifical metal as removed from solution.

Pully cover after a few passes with a wire brush

The black comes off very easily. A power washer will make quick work of the black stuff.

Next I will get a flat tub to do my engine tin and sway bars. I also going to see if i can devise a way to do nuts and bolts. Perhapse place them in a wire cage?

PS- pardon the spelling errs the spell check isnt working. I know there are some mistakes.

drcoastline · 03-26-2011, 07:37 AM

Oh yeah almost forgot. When you are finished you can just dump the solution in your grass or down the drain, it won't hurt anything.

Traveller · Traveller's Garage

Interesting. I'll have to try it. You might try heating the solution as I did below.

I've used Heavy Duty Radiator Flush to remove rust from the insides of a motorcycle gas tank.

I'd first clean out the insides of the gas tank with detergent and water to get rid of the gas residue, then I'd fill the gas tank part way with hot water (speeds up the reaction), then add the HD Radiator Flush, shake the gas tank to dissolve the chemical (it was a white powdery crystal), and then top up with boiling water (to increase the temperature of the water and the reaction). You don't want to add the boiling water first as it may damage painted surfaces.

I've also used Molasses.

Ideally, you only want to remove the iron-oxide and none of the metal.

Google is your friend.

drcoastline · 03-26-2011, 08:23 AM

Traveller, Thanks for the input. I may need to use your version for the gas tank in my boat. We had quite a scare last summer. I got a call from the Dock Master of a strong smell of fuel coming from my boat. Sure enough when I showed up the bilge had about 10 gallons of fuel laying in the bottom. Fortunately the level hadn't risen to the height to trigger the float switch on the pumps. That may not have turned out so well. We immediatelly pulled the boat and over the next few days the tank emptied it's self into the bilge. Nearly 100 gallons.

The process I posted does not remove any metal that is why I wanted to give it a try.

Traveller · Traveller's Garage

Quote:

Originally Posted by drcoastline

TSure enough when I showed up the bilge had about 10 gallons of fuel laying in the bottom.

I hope you didn't use a lighter to check?

MrJTP · 03-26-2011, 08:47 AM

I've been using this method for a couple years now and it works quite well. Here's a couple of front fender supports of my 68:

I found the method described here: Electrolytic Rust Removal

Toward the end of the article he mentions the possibility of hydrogen embrittlement which might be important if using this method on structural parts. Baking the article can eliminate some or all of the problem but I've read several articles about it and they all have different opinions.

steely · 03-26-2011, 10:37 AM

Now that's cool - but for some reason now I have Thomas Dolbys' She blinded me with science playing in my head

I honestly never heard of this for rust removal - looks great.

drcoastline · 03-26-2011, 03:23 PM

Quote:

Originally Posted by steely

Now that's cool - but for some reason now I have Thomas Dolbys' She blinded me with science playing in my head

I honestly never heard of this for rust removal - looks great.

I was thinking "Weird Science"

drcoastline · 03-26-2011, 03:39 PM

I wonder if this thing can turn this...

Back into this...

nineball · 03-26-2011, 03:53 PM

found the sacrificial piece for that...

drcoastline · 03-27-2011, 08:19 AM

Last night I did a few more pieces.

I wired together a few cold chisels and two pieces of rusted fender from under my headlight. I was curious to see how multiple pieces would come out and what the rusted sheet metal would look like. If it would have enough decent metal to salvage and weld back in vs. manufacturing a new piece. These went in at 3PM and came out @ 11AM.

All parts after a few passes of a wire wheel on my angle grinder.

The sheet metal cleaned up enough that I can re-use them. I will weld in a patch then weld the piece back onto the fender. This should save a lot of time manufacturing new pieces with a compound curve.