Derusting muzzle loader bore

>cross-posted<<
Today I scored a muzzle loader at a yard sale for a measly 15 bucks .
Great deal , right ? Well , maybe . I got looking at the bore a bit ago
and there is some pretty heavy rust in there - much more than I expected
from the condition of the outside .
I believe the 2 top contenders for derusting are phosphoric acid and
Evaporust . I'm wondering which will be best in this situation . I
intend to cast some lead laps to polish the bore if needed , but I won't
know the true condition until the rust is gone . And the barrel may not
be salvageable ...
The plan is to pull the breech plug and strip the barrel , stick it
inside a piece of PVC of the proper size and fill the pipe with solution
. Pumping a bore brush in the barrel to circulate fresh solution will be
done periodically .
So kids , which shall it be ?
Reply to
Snag
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I've used EvaporRust and its "okay." It neutralizes most rust, but in the case of a muzzle loader bore I'd probably power a brass brush through at several times, and then take a look at what's left. The biggest issue would be if the muzzle is eroded. The crown and muzzle are as important to accuracy as the rifling. Honestly some pretty bad rifling can still spin stabilize the bullet, but the muzzle needs to be uniform. Often if the crown is messed up they can be recrowned.
I've shot BP since my mid teens. Maybe 40 years. Not an expert... well except at doing things wrong.
Reply to
Bob La Londe
I think there's decent rifling under the rust , for sure the muzzle and the last couple of inches look not too bad, we'll see after I scrub it out . I hesitate to use anything solvent based , I think soap and water first off with a brass brush . Somewhere around here I think I have a small bottle of JB's Bore Scrub . I used that stuff to polish a 22-250 bore many years ago and it went from 3/4" groups to under 5/8 ' ... actually I almost hope it needs to be rebarrelled . Gives me a chance to maybe build a .36 to match my C&B revolver .
Reply to
Snag
Citric acid is great for heavier derusting. The converted iron citrate is easier to remove from the surface than iron phosphate. Phosphoric acid is better for light rust when you intend to paint over it afterwards, as the iron phosphate is stable and won't loosen.
Reply to
Clifford Heath
I think we have a bottle of powdered CA on the shelf ... we use it when we can tomatoes !
Reply to
Snag
I think we have a bottle of powdered CA on the shelf ... we use it when we can tomatoes !
Snag Let's Go Brandon !
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How about electrolytic derusting??
Reply to
Jim Wilkins
I'm not sure electrolytic will work inside that confined space , not much circulation of the solution .
Reply to
Snag
One not mentioned, Oxalic acid...
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Reply to
wws
One not mentioned, Oxalic acid...
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Be careful, oxalic acid is toxic.
Reply to
Jim Wilkins
I'm not sure electrolytic will work inside that confined space , not much circulation of the solution .
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I asked to see if anyone had obtained good results. I would expect difficulty sealing the ends into a circulating system and insulating a central iron wire. Maybe a spiral of string around it would be enough? I bought Flex paste to make custom rubber parts such as odd sized tubing adapters and antiskid feet but wasn't impressed with its low tear strength. Perhaps you could turn tubing to barrel adapters from wood and line them with Flex or liquid electrical tape.
Reply to
Jim Wilkins
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No idea if it works but the shrink tubing idea sounds good.
Reply to
rbowman
As a long-time blacksmith with an equally long conflict with rust, I'm for phospohoric acid. Residual iron phosphate is good but you're proably going to polish that away.
If your shop is chilly, heat the acid bath to high room temp, say 80F. If there's flakey rust, periodically remove it manually and return to the bath.
Yeah, that. Except if the bore brush is bronze, maybe you don't want to get it into the acid?
Reply to
Mike Spencer
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No idea if it works but the shrink tubing idea sounds good.
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Thanks. I have fiberglass braided sleeving ( high temp insulation) I could use but I'd be surprised if anyone else does.
Ammonia, citric and oxalic acid all cluster around metal ions and make them soluble in water. They generally don't attack solid metal as much as the stronger acids do.
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When I had KP I noticed that pouring leftover Army coffee over the formerly galvanized sinks would rust strip all the new rust off.
Reply to
Jim Wilkins
Yeah, that. Except if the bore brush is bronze, maybe you don't want to get it into the acid?
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Acids can dissolve Nylon too.
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Reply to
Jim Wilkins
Slotted sleeves over the ends of the barrel , plugs in those made of HDPE drilled to hold a TIG electrode centered in the barrel . Suspend in a PVC pipe full of electrolyte with an aquarium pump air stone alongside the barrel to set up circulation . We've been discussing this over at the Logan Lathe email list .
Reply to
Snag
Oxalic toxicity is over-rated. In excess, it crystallizes to form kidney stones. We eat rhubarb because it has that nice oxalic taste, but we don't eat the leaves because they have too much.
Another note: oxalic acid is used to treat black iron tannate stains from nails in timber-work. It converts it to the invisible iron oxalate. That's what's used in products like Kleen-wood, etc.
Reply to
Clifford Heath
I've used an aquarium pump when etching circuit boards to keep things stirred up. It worked great. Well, as great as anything involving ferric chloride can be.
Reply to
rbowman
I've had mixed results with evaporust. It does remove rust, but it will then suddenly darken steel, and that's even harder to clean.
Reply to
Cydrome Leader
Slotted sleeves over the ends of the barrel , plugs in those made of HDPE drilled to hold a TIG electrode centered in the barrel . Suspend in a PVC pipe full of electrolyte with an aquarium pump air stone alongside the barrel to set up circulation . We've been discussing this over at the Logan Lathe email list . Snag Let's Go Brandon !
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OK. I was trying to think of a setup that wouldn't affect the bluing or browning on the outside.
Reply to
Jim Wilkins
It's blued , but it has some rust too . It'll be brown when I'm finished with it .
Reply to
Snag

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