I have mentioned elsewhere about electrolytic rust removal. Probably a few out there who don't know about it, so just in case, heres a brief run down of how I go about it.
I use a plastic tub of a size suitable for the part to be de-rusted, from big rubbish bins, to ice-cream containers. I mix a couple of handfuls of bicarb soda into the water in the tub and make sure it is disolved well. Then hook up the POSITIVE lead from my 4 amp battery charger to the business end of an old spade - any steel will do, some use stainless steel sheet - and put this in the solution. The NEGATIVE lead is clamped to the piece to be derusted, and the whole process starts.
After a few minutes you should see very fine bubbles starting to pop on the surface of the water, and may even see minute bubbles rising from the rusty piece. I leave the piece in the solution for some hours - sometimes a couple of days, until the rust has been removed.
Then, hose it down, wipe it dry, wire brush it if needed, and either paint it or spray with a light oil - WD40 - if it is not going to be painted - you need to either of these things to prevent rust reforming.
This method won't hurt metal, works only on steel/iron, removes rust including the rust under paint (and then the paint will flake off). The soltion can be reused until it is too disgusting - lots of rusty foam will form and there will be a sludge at the bottom of the container.
Just check to make sure you have good electrical connections - usually you will see fine sparks as you connect the lead. The other method to check good connections of the lead to each piece of metal is to very briefly short across the two pieces of metal with a wire - sparksa indicate that you have good connections.
This method is great for getting into hard to reach places, loosening frozen nuts and bolts, etc. Just needs a little patience. There is a lot of onfo on the net too.
Hope this helps somebody.
Jeff
Last edited by Jeff49; 10/08/11 02:16 AM. Reason: typo
