cleaning with electrolysis

[munkee]

Hey all. I was doing some reading on this process and was wondering if anyone has tried it. I'm not sure how well it would work with the runners to just have them in a tank. Might have to run the anode through the runners? Also, what would be the effect of coating the inside of the runners with something like por-15? Thanks, Chris.

 

[HotRodKid]

ive tried it on clean pieces

its mostly for cleaning rust / corrosion off pieces, and probably wont work if theres a coating of crap on the surface

its also a "line of sight" process, any surface that cant "see" the sacrificial material wont get processed. you also have to be carefull with aluminium, as its easy to damage the part, and machined surfaces can wind up damaged beyond use

 

[93rev2sev]

It's great for cleaning an old ax that someone left at the base of a tree for a year...but for a car...It's not very effective or practical.

 

[HotRodKid]

its quite practical for car parts actually. its how i did alex's charge pipe on his sho for example.

its also highly effective, as it cleans deeper then any mechanical process, short of grinding the material down

all you do is wire brush off the major stuff, then drop the pieces in the tank for a few hours, once done pull them out, dry them off completely, and wire brush them again to get off all the (now converted) rust dust.

its less work then sanding and wire brushing for hours, and it gets EVERYTHING thats line of sight.

floorboards for example can be cleaned by laying a foam pad down, soaking it with the solution, then laying your sacrificial steel on top. resoak from time to time, and you wind up with a floor thats totaly rust free

or a set of aluminium wheels, clean all the big stuff off, maybe run a sander over the corrosion to get things started, then drop them in a plastic tub and get them spotless with this process - way better then sanding everything by hand

 

[93rev2sev]

Floorboards?

I thought the item had to be immersed...I never thought of that method.

 

[munkee]

I was thinking about trying it on a set of basketweaves just to see what it does. I knew it worked by reversing oxidation (basically), I wasn't sure how much oxidation can occur in aluminum without it being very noticeable. I have a few intakes and heads laying around so I might set up a tank and try it.

 

[redwraith94]

I used it before on my Ford Tempo, to remove the EGR pipe from the adapter on the exhaust manifold, that was cast iron, and steel. But it cleaned it extremely well, before it corroded the pieces apart I used some Hydrochloric Acid (Muriatic acid), along with table salt.

For Aluminum, Table salt would work well, I wouldn't recommend any acids, or bases for Aluminum though.

I assume you will be hooking the negative electrode to the aluminum? It is an extremely reactive metal, and actually forms a very thin oxide layer immediately, when it is exposed to oxygen. The Aluminum oxide, is the same ceramic as sapphire, and it is extremely tenacious. If you hook the positive electrode the Aluminum will corrode rapidly, and usually will take on a dark grayish appearance.

For cleaning corrosion it works well, but make sure the parts are free of grease first, normal salt water (the electrolyte) will not do anything against grease, and don't use electrolytic cleaning for that. If you do, it will be uneven, and probably cause pitting.

For Aluminum it actually works by corroding the metal underneath the corrosion (making more Aluminum Oxide), which makes the uneven rough corrosion fall off. This leaves you with a thin, uniform layer of corrosion.

If you don't get the results that you are looking for, you could try posting here:

http://www.metalfinishing.com/asktheexpert/index.htm

These guys take a bit to respond, but are extremely knowledgeable, and very helpful.