Electrolysis, or "how to de-rust while sleeping"

[David Lawrence]

I have made an electrolysis bucket. Then i cut the top of an old brake disk to make an electrode at the bottom of the bucket, connected to that i welded on a length of threaded rod, then i have hung the caliper off another length of threaded rod fastend on by steel wire.

Its cooking now. Must say i didnt expect quite so many bubbles.

[smudge.g]

Originally Posted by neilb740

I have used this method to loosen crud from coins found with my metal detector. so i can tell you It works fine on bronze as well. Not sure about other metals.

if you use salt in the water, it will destroy any copper or brass fittings. Bicarb is the safest substance to use. (learnt from experience!!)

[vacuman]

That's really useful to learn...plus I have some Escort calipers to practice with. Thanks

[David Lawrence]

Not sure how to work with this new imaging site yet. This should be a photo of the caliper before i started.

seems to either come too small or too big.

Here it is in the bucket with a smart charger via an old car battery, connecting to the electrodes.

[Pete]

I've used this method a lot over the years, mainly on bike stuff or the Minor parts. I leave it for a couple of days with the charge provided by a very old charger unit and a circuit breaker in the line to prevent any mishaps. Always comes up trumps.

I've seen a complete 190 rear subframe and vented disc brakes in a scrapyard, and the calipers may get done this way.

[Avulon]

I've been using this recently. I have a flat wide container from the local branch of one of the diy stores and some lengths of rebar for electrodes. Electrolyte is laundry soda in water and power is courtesy of an old laptop power supply 18.5v 3A. Works a treat.

[David Lawrence]

Originally Posted by Avulon

I've been using this recently. I have a flat wide container from the local branch of one of the diy stores and some lengths of rebar for electrodes. Electrolyte is laundry soda in water and power is courtesy of an old laptop power supply 18.5v 3A. Works a treat.

My caliper is now shiny silver coloured on the side facing the electrode, so i have now turned it over. The carriers look like they are going to take a bit longer.

I am using laundry soda as well. The process appears to be slowing down. Far less bubbles than when i first set it off. Dont know if this is because the rust has mostly transferred now or because some chemical change has taken place in the electrolyte.

The electrode is now caked in a thick crust of rust. As a side benefit, the old car battery which i thought was completely dead appears to have been revived as well.

[ceedy]

you probably should use the battery with a light bulb in the circuit to control the current .

Used to do it this way years back . along with nickel plating in the same vein.

C.

[KWIL]

I would discard any bolts as there is the risk of hydrogen embrittlement which causes loss of tensile strength.

[Avulon]

Originally Posted by David Lawrence

I am using laundry soda as well. The process appears to be slowing down. Far less bubbles than when i first set it off. Dont know if this is because the rust has mostly transferred now or because some chemical change has taken place in the electrolyte.

The electrode is now caked in a thick crust of rust. As a side benefit, the old car battery which i thought was completely dead appears to have been revived as well.

Whenever it appears to slow down just switch it off and clean the crud off of the electrode: and clear the black layer of lifted loose rust off of the piece being derusted. And then switch back on to continue. The electrolyte is unchanged - it's only purpose is to help the current to flow.

Over time the water level will drop from evaporation (increasing the electrolyte concentration and therefore the current being drawn), just top back up to the previous level with plain water.

I've cleaned mine out once now from the build up of rust silt in the bottom of the tank, thinking of adding a drain into the bottom to drain it all into a tall container underneath, let it settle then pump back all but the silt.