Electrolytic barrel de-rusting

Grouse Man

Grouse Man

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As some of you may know, I'm cleaning up an Ugartechea double which had been neglected. The barrels have some rust inside and out. The bluing is mostly okay so I'd rather not completely strip off all the rust and bluing with something like CLR or vinegar. My thought was to use the electrolysis method by submerging the barrels. I just confirmed that my home-built tank works (rusted exhaust manifold) so I'm confident about the method.

One thing I know to watch out for is the fact that the upper hole for the ejectors at the breach end goes into the hollowed area captured by the upper and lower ribs, I'd rather not water get into that area. I plan on closing that hole off with a wax plug, or RTV silicon or hot glue - something easily removed. But is there anything else to watch out for? Would the rib solder be adversely effected by this method?
 
Sorry to disappoint you but that method will remove all blue out of everywhere. Don't know abou the solder though. I derusted a gew 98 & while it removed all the rust without damaging the steel, it left no blue at all.
 
I'll check the reference source where I found that info intially, but I thought it was NOT removing the bluing. Let me check . . . seems to me it was on a Muzzleloading forum which for some reason is now not letting guests view it. Wait some more . . .
 
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Gun bluing (or browning) is nothing more than a controlled rusting effected by special oxidising mixtures or pastes.
"The rust first formed consists mostly of ferrous hydroxide, which on exposure gradually becomes converted into brown ferric oxide. Subjected to the action of boiling water or steam, the brown oxide is converted into the much darker, so-called "magnetic" oxide (ferro-ferric oxide), the coating thereby mostly becoming black. By suitable additions to the browning solution (and to a lesser degree by after-treatment) the coating can be given a more or less brownish, bluish or black-bluish tone, without modifying the fundamental difference between brown and black colouring."
(From "Firearm Bluing and Browning" by R.A. Angier.)

So like Desporterizer stated above all of the rust would be removed.
 
Grouse Man said:
Well, I guess that ends that little experiment. Thanks for saving me!
Click to expand...

Or remove all of the "rust" and reblue the whole barrel. You can practice on your piece of tail pipe that you de-rusted. You will teach yourself a useful technique that you may use on future projects. Good gunsmithing!
 
The jury is still out. I checked the forum where I found it, and the fellow indicated that the bluing was still there. He referred to the gun as caked with rust. So, theory says the bluing would be removed, but at least one experience says otherwise.

So now we need to do another experiment. Anybody have a piece of rusty blued steel they'd care to experiment with? The instructions are dead simple.
 
I maybe responded to that a little over-simplistically.

Look at it this way:

It is very difficult to "grow" a thick coat of blue on steel because the thicker the coat, the less reactive that coat becomes - the fewer free molecules of iron are available to bond with free oxygen molecules. So the bluing, with an oil treatment, is largely non-reactive to oxidization in the absence of an abundance of water or catalysts like salt.

However, bluing is not a "normal" occurrence of oxidization. It's a "conversion" of normal red rust using chemicals and circumstances not typically occurring in nature.

And that converted oxide can revert under the right circumstances.

When air and moisture get a foothold in the blue, it reverts to the more chemically active red rust. Because red rust is more reactive, it pulls away, or flakes from the surface of the metal as it combines and recombines with oxygen and iron, exposing more fresh iron for the reaction.

As such, rust oxide does not have as strong of a bond with the steel as blue (or black) oxide, which is why, with a soft brass brush and some solvent, we can brush off "growths" of rust from a firearm. But brush too hard or too long, and you do remove the bluing as well.

So I think that your source on the other forum is applying a very gentle treatment that is dislodging the surface rust.

Suggesting that one could electrolytically remove one form of oxide while retaining another suggests a level of technological sophistication that is both hard to believe, and difficult to see offered as free advice on the internet.
 
Now that I think of it, the father-in-law has a couple of rusty old fenceposts which used to be guns . . . they might have some bluing on them.
 
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