Electrolysis question

[wrndln]

I have an engine that has a fair amount of rust in the valve area. The camshaft, valves, spring, etc. are still in the engine. The parts are stuck in the engine. Everything else is removed from the block. I was thinking of putting the engine in my big electrolysis tank and "cook" it for a week or so. I have heard of hydrogen embrittlement on some parts. I don't care about the valve springs, guides, valves, but I think the camshaft might be usable. Does anyone have any opinion about whether the electrolysis would harm the camshaft?
Thanks for any help.
Rusty Nelson

[1931 flamingo]

Why not pull the shaft if you're concerned??
Paul

[Special Coupe Frank]

"...The camshaft, valves, spring, etc. are still in the engine. The parts are stuck in the engine..."

[wrndln]

Thanks, Frank for clarifying my post. I would remove the camshaft if I could before putting it in the tank. I guess I could cut off the valves and spring if necessary to free up the camshaft.
Rusty Nelson

[jhowes]

I did this to a block that I dug out of the dirt but it took a year for the process to give me the clean engine that I wanted. I had to bore it out to get ride of the rust pits 125 thousands. Then plane the deck for the same reason. Re babbiting seems necessary because the electrolysis process is not kind to babbit it seems Also magneflux looking for cracks is a good idea.

[Special Coupe Frank]

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Rusty,

I wonder if you laid the block on its side, valve-side up, and flooded the valve ports / stems with Kroil, PB Blaster, or even ATF/Kerosene, if things would loosen-up enough for you to work the valves loose enough to pull the cam ?

[hop2it]

Rusty,
50/50 acetone and ATF ,the electrolysis system I am familiar with uses washing soda which is alkaline and water powered by a battery charger, it is acid dipping that causes hydrogen inbrittlement. Check out Redistrip I think they are in Indionapolis hop this sheds some light on the subject
Doug

[oldmanandakid]

At the risk of highjacking Rusty's thread maybe some of the engineers here can talk a bit more about the embrittlement issue. Is there any general guidance about how long and which metals or Model A components can safely be given the home electrolysis treatment?

[wrndln]

Frank,
I was think about putting a lot of penetrating oil in the valve gallery like you suggested, but one small leak and it would run out before the other parts were freed up. Maybe I could just spray some on the valves, keepers, valve guides and see if they would loosen. I would probably have to keep spraying the penetrating oil on many times to do any good.
Rusty Nelson

[wadsies1]

They say a bath of molasses will remove all sorts of corrosion. Have not tried it myself but have been told it works really well.

[Mitch//pa]

submerge it in evaporust

[dave in australia]

Originally Posted by hop2it

Rusty,
50/50 acetone and ATF ,the electrolysis system I am familiar with uses washing soda which is alkaline and water powered by a battery charger, it is acid dipping that causes hydrogen inbrittlement. Check out Redistrip I think they are in Indionapolis hop this sheds some light on the subject
Doug

Alkaline solutions will also produce hydrogen embrittlement. It is the production of ionic hydrogen at the cathode getting trapped with what is plated. As no metal is being plated, although the part is cathodic, embrittlement with this cleaning is not an issue. When I was an electroplater, and we cad plated aircraft parts, embrittlement was a major problem, so we would bake the parts after plating. The cad bath is a highly alkiline solution, so it is not just acidic solutions.

[MikeK]

Hydrogen embrittlement occurs when Hydrogen forms at the surface and penetrates the grain boundaries of the alloy. This occurs both in electro cleaning and plating operations. The result is micro expansion of cracks over the next few days. Think of it like water getting into a tiny concrete crack and freezing. The crack opens. Likewise with the metal grain boundaries.

Used parts with micro stress cracks will fare the worst. I would avoid the process on any grade 5 or 8 fasteners, springs, weldments, drive shafts or axles, and suspension components. Used sheet metal that appears OK may develop cracks if flexed, like the fenders in the bead area over the wheel. The hydrogen can be removed after your process by baking the parts @375-400F for about 100 hours (yes, 100!) You need to begin the baking within a few hours of completion of your cleaning process. Extended electrolytic cleaning, in excess of 24 hours may cause unrecoverable damage.

For non-critical parts an acid neutralizing rinse followed by heating the parts to 300F for a few minutes to dry them will be fine.

SAE AMS 2759/9 spells out the procedures for embrittlement relief.

[Cool Hand Lurker]

Interesting posts. Thank you.
Would doing the electrolysis process in a vacuum pull away the hydrogen quickly enough so it would not embrittle the part? Could vacuum be safely used in this process?

[oliverguy]

I would try it, what do you have to loose if it's a big ball of rust now. I'm using electrolysis a lot now, but never did anything like an engine. A carb casting cleans up nice. Nothing seems brittle to me afterwards.After the part is done I soak it in vingar for a little while to loosen the carbon (I use a carbon cutting electrode). The speed is based on the size of your electrodes, the concentraion of your solution and the amount of amps you put to it. It's fun to do. For something big I'd suggest doing it outside.

I strain off the garbage and reuse the water, just adding more occationally.

[dave in australia]

Originally Posted by Cool Hand Lurker

Interesting posts. Thank you.
Would doing the electrolysis process in a vacuum pull away the hydrogen quickly enough so it would not embrittle the part? Could vacuum be safely used in this process?

No, it would not make a difference.

[Mad Mac]

Originally Posted by wadsies1

They say a bath of molasses will remove all sorts of corrosion. Have not tried it myself but have been told it works really well.

Molasses is cheap, harmless and works surprisingly well as a rust remover. However it is a lot less effective where there is oil or grease on the metal, so I guess it would not be so good in this situation.