Electrolysis for rust removal

I was much interested in this thread, and after reading up on it at http://www2.interconnect.net/nlindsey/Electrolysis/Electrolysis.htm I was convinced to give it a try.

So when I got home last night I dug out a *BIG* bucket (about 7 gallon :) and the battery charger and some caustic soda (Sodium Hydroxide).

I made up the solution as suggested: 1 tablespoon of soda per gallon of water. I then found the anode (old brake drum :) which I hung from one of the bucket's handles with a little above water to connect the battery charger +ve.

To test I decided to try and remove the (minor) surface rust off my 12G295 head - which also had some rust down one of the valve throats - so this was lowered into the solution.

I then connected up the battery charger -ve to this and switched on. My charger meter showed about 5A flowing! and bubbles soon appeared on the surface.

I left it about 20 minutes (it was only minor surface rust) and checked - the result was great! Because the head couldn't be fully submerged I had to turn it over several times to get top/bottom and front/back done.

The head was then removed and I washed it down with the garden hose, before getting the water off/out with an old towel. Finally I sprayed the head liberally with WD40 (including inside ports, oilways and water galleries) to keep further rusting at bay. This weekend I'll check that it's properly dry and then I'll lightly oil it for storage.

Have a go - it is really simple and seems to work very well.

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Electrolytic cleaning solution

Recipe for electrolytic cleaner!

Store in a polyethylene bottle. Alkaline solutions attack glass. Wear rubber gloves when working with this stuff. It's not all that bad but I wouldn't want to bathe in it.

• Use a carbon or graphite rod (don't use metal) wrapped with a swab of cotton batting as anode (positive). I made an electrode holder out of nylon and stainless steel.
• Connect a 6 to 12 volt power source (such as a small battery charger) with the positive to the anode and the negative to the work piece. DON'T USE A CAR BATTERY FOR POWER! If you wear through the cotton by accident a high current can flow with damaging results.
• Use a glass or plastic dish (like a pyrex baking dish) to work in - don't use metal, it will contaminate your work.
• Connect the power and wash the work with the swab. You'll see quite a bit of foaming if everything is hooked up correctly.
• When done, rinse thoroughly. This leaves a very clean surface so you will need to apply some protection on steel imediately to prevent it rusting.

This is a very gentle metal cleaner. I have used it to clean very thin copper, silver and gold plate without damage. I have also used it to clean various metals, including steels, preparatory to plating. You can make a plating/cleaning power supply with a small variac, a twelve volt transformer and a bridge rectifier.

Enjoy!

Article by Ted Edwards (Ted_E@bc.sympatico.ca) from http://www.metalworking.com/dropbox/E-CLEAN.TXT