Stopping Rust in Old ML Barrels

[fourarmed]

I was getting my great-grandfather's half-stock percussion rifle cleaned up to pass along to a cousin, as I have no direct descendents of my own. This rifle had been fired and thoroughly cleaned in about 1958 or so, but the bore was quite rusty. I heated the breech end of the barrel lightly with a propane torch until I could get out the breech plug, then brushed and patched the bore with various cleaners/rust removers until I was getting only light rust on the patches.

Sitting by my workbench was a bottle of "Ospho," a phosphoric acid mixture that is sold in hardware and paint stores for applying to rusted iron and steel to prepare it for painting. It claims to turn iron oxide into iron phosphate, "a hard, inert compound." I decided since the rifle will almost certainly never be fired again, that it could not hurt to run a few patches of this through the bore. I did so, and let it sit for a couple of days. I ran a patch through it, and it came out clean. I patched it thoroughly with RIG, and sent it on to its next life.

One added point of interest about this rifle: When I took the barrel out of the stock, I found a strip of cloth that had apparently been placed there to tighten up the fit of barrel to stock. This was like no modern cloth I have ever seen. It was a dark color with small white flecks distributed through it where a lighter thread showed up in the weave. I wish I had taken a picture of it. I suspect it was homespun, or perhaps linsey-woolsey. It was quite old, however, and must have been there when my father cleaned the gun last in the '50s, as it is clearly much older than that.

[oldred]

You could not have chosen a better product to swab that bore with! OSPHO or any number of other Phosphoric acid products sold for the same purpose work like magic and not only do they dissolve rust but they leave a rust resistant "pickled" surface, any tiny specs of rust that might be left down in the bottoms of pits will be converted and left inert instead of continuing to grow in the presence of moisture/oxygen. OSPHO is probably the original rust remover and has been a favorite for this purpose for well over 75 years, sounds like you left that bore in great condition to prevent further rusting.

[ndnchf]

For an application like this rifle I recommend a product called Boeshield. It was developed by Boeing for corrosion protection of high end aerospace/aircraft parts. But it is can be used for many other less exotic applications. I use it on bare metal machine tool surfaces. In a rifle like yours that will not likely be shot again, a good application of Boeshield to the bore will protect it for many years. Read up on it here:

http://boeshield.com/why-boeshield/

[curator]

When "conserving" an old firearm most museum curators use "renaissance wax" on the outside and one of the Alox compounds on the inside. I use "Lee liquid alox" in the bores when putting antique rifles into storage. Works better than cosmoline and is much easier to remove.

[rr2241tx]

Oxpho followed by a light coat of RIG to prevent future moisture contact and the bore should last until the barrel rusts through from the outside. Might plug the bore with rancid Ruskie cosmolene just for the air freshner effect.

[oldred]

Might plug the bore with rancid Ruskie cosmolene just for the air freshner effect.


Lol, Good one!

[country gent]

I have used bullet lubes for long term storage in bores. SPG or emmerets with a beeswax base and fat oil mix works well. The oils seal out air and the beeswax dosnt flow or run to disapear over time like oils do. You do need to remember to remove it before firing though. I have seen muzzle loaders done with a heavy coat (and hair drier to wrm help spread coat.) that have been stored 30-40 years and when lube is removed the bore is still pristine

[plus1hdcp]

When "conserving" an old firearm most museum curators use "renaissance wax" on the outside and one of the Alox compounds on the inside. I use "Lee liquid alox" in the bores when putting antique rifles into storage. Works better than cosmoline and is much easier to remove.

I will have to remember your use of Lee liquid alox, thanks for posting.

[fourarmed]

Had the bore been pristine, I would probably have just given it a coat of RIG, but it was far from it, and I wanted to stop the rust that was already there. I have been told that the surface left by Ospho is not that different from Parkerizing.

[oldred]

I have been told that the surface left by Ospho is not that different from Parkerizing.


You were told correct and what you did was spot on as far as STOPPING the rust vs just putting it in hibernation by smothering it with oil or grease, even cosmoline only smothers off the oxygen/moisture and will keep rust at bay only as long as it isn't removed for some reason. By using the Phosphoric acid solution (OSPHO) you "put out the fire" so to speak and chemically stopped the iron and oxygen reaction taking place on the surface, you definitely did the right thing by first actually stopping the chemical reaction going on during the rusting process. This also left the surface infused with an inactive layer so that the rust is not even trying to come back and won't unless exposed to excessive moisture or a corrosive agent of some type to restart the oxidation process. While oils, grease, cosmoline etc do a pretty good job of keeping rust at bay they actually do nothing to really stop it, the chemical reaction between the iron and oxygen is still potentially active and these products serve only to cut off the oxygen supply -as soon as oxygen contacts the surface again this latent oxidation process will flare up and start the rusting process all over again!