Author Topic: clean up rusted barrel? (Read 3567 times)

Ravenshurst · « **on:** December 06, 2022, 10:19:26 AM »

Hi all
Not sure if this is the right place for this...
A friend of mine buys the contents of not-paid-for storage sheds....
Yeah. I know. But it's true.
So, he gave me a seriously rusted barrel, and a pre carved stock. The barrel is 36 inches long, marked .50 caliber, straight 7/8 across the flats, and marked with an 'M' inside a circle. According to the 'net this is a Green Mountain 1:70. barrel. It is kinda rusted/ sorta patine'd on the outside. The bore actually looks surprisingly good, mostly. I think I can clean most of it up....BUT...the first few inches of the muzzle are REALLY rusted, badly built up. Does anyone have any advice on cleaning up this barrel? Or should I just cut it down to 30 inches? Or just throw it away? Any advice would be appreciated. Thanks.

foxm2015 · « **Reply #1 on:** December 06, 2022, 01:16:25 PM »

Place the heavily rusted end in a heavy duty container, pour in a quantity of automatic transmission fluid past the level of the heavily rusted area, and let it soak for a while. Find some large diameter brass brazing rod, cut to workable length(s) and file angle to make scraper(s) that will fit well between the lands and grooves. After a while start with the brass scrapers and work the rusted areas to see what can be removed. Check your progress. If happy with what you see switch to bronze bore brushes / scotchbrite pad strips on a cleaning rod and work the area. Maybe able to salvage, maybe not. A "box of chocolates" project for sure.

After a good cleaning you will be able to better determine if you want to go the cut-down route and where to start or use as is. Give it a try, nothing invested but time......

Good luck with the project.

Don Steele · « **Reply #2 on:** December 06, 2022, 01:50:01 PM »

I've used Evaporust to totally remove rust from a shotgun barrel that was retrieved from a barrel of rainwater behind an old gunshop. Cap one end of a piece of PVC pipe that's longer than the barrel, drop the barrel in then fill the pipe with Evaporust until the barrel is completely submerged. Leave it overnight, check it in the morning.
For the GM barrel in question, you can evaluate it's actual condition after Evaporust has brought it back to bare metal and you can see what you have to work with.

rich pierce · « **Reply #3 on:** December 06, 2022, 04:02:13 PM »

Once the rust is gone you’ll have pits left behind that will need to be lapped out. I’d unbreech the barrel first before cleaning, if it’s breeched.

Marcruger · « **Reply #4 on:** December 06, 2022, 04:13:55 PM »

The good news is that it is a straight barrel and GM still makes those. If you need to replace it you can. God bless, Marc

Pukka Bundook · « **Reply #5 on:** December 06, 2022, 05:14:58 PM »

Dumping the barrel in a trough of white vinegar will remove the rust.
I don't think the pitting will be as bad as on an ancient barrel and this usually works well.
after a few days it can be cleaned off pretty easily, washed, dried and oiled.

Caustic soda will also take the rust off, but be careful with this stuff and boiling water, it gets riled up. Don't get caustic on your skin, as it'll eat it.

Richard.

Top Jaw · « **Reply #6 on:** December 06, 2022, 06:08:49 PM »

Your main concern is the bore in that more rusted section. After you do some of these suggested treatments and evaluate the bore, that will determine your path forward. The outside can be draw filed to remove most or even all of the pitting - if not super deep. Pitting in the bore, and on the crown may necessitate a barrel Bob and recrown, or perhaps you could cone the inside of the muzzle if it is mainly an impact in the last inch or two. This would likely remove it. My 3 cents.

T*O*F · « **Reply #7 on:** December 06, 2022, 06:37:06 PM »

Quote from: Don Steele on December 06, 2022, 01:50:01 PM

I've used Evaporust to totally remove rust from a shotgun barrel that was retrieved from a barrel of rainwater behind an old gunshop. Cap one end of a piece of PVC pipe that's longer than the barrel, drop the barrel in then fill the pipe with Evaporust until the barrel is completely submerged. Leave it overnight, check it in the morning.
For the GM barrel in question, you can evaluate it's actual condition after Evaporust has brought it back to bare metal and you can see what you have to work with.

Ditto on this method. It's completely non-destructive and removes only the rust. It can be re-used afterwards for other projects and is environmentally safe for disposal. You can buy it at most auto parts stores. I've used it numerous times for locks, barrels and heavily rusted modern firearms.

Ravenshurst · « **Reply #8 on:** December 06, 2022, 07:18:04 PM »

Wow!
Gentlemen, thank you for so much advice!
The barrel is not breeched. The outside of the barrel is growing a patina for most of its length (except for a few inches at the muzzle which is crusty rusty) and isn't pitted. The bore at the breech end doesn't appear to be pitted.
Vinegar, ATF or Evaporust? Everyone has their favorite. I will probably try the Evaporust, as it is specifically designed to remove rust, and has good reviews.
I planned on coning the barrel of my rifle anyway.
This isn't the style of rifle I wanted to build, but hey, free is free. If I can clean up the barrel, great. If I can't nothing lost.

Mule Brain · « **Reply #9 on:** December 06, 2022, 07:42:39 PM »

I use the evapo rust as well. I put together different sizes of pvc pipes capped on one end. I run a copper wire through the barrel and attach a washer, so you can pull the barrel straight up out of the tube that way.

recurve · « **Reply #10 on:** December 06, 2022, 08:00:25 PM »

my first thought is the barrel might be browned and the inside might need a good scrubbing with kroll oil and pad a green scotch please post photo the upper barrel is browned the lower is blued browning looks rusted to the new to muzzle loaders

instead of cutting you could cone the barrel and polish the crown

Scota4570 · « **Reply #11 on:** December 06, 2022, 08:09:01 PM »

If it is a blank you will need to draw file and polish. That will take the rust off. IF you want it clean first I also endorse Evaporust.

IN my working life I was occasionally tasked with doing ballistic testing on guns that were rusted to badly to be fired. After years of other methods, we found Evaporust to be the hands down winner. It was important to retain any microscopic striated markings for comparison purposes. Evaporust was the only method that removed the rust and did not disturb intact steel. Basically you can not hurt the bore with Exaporust by immersing the whole barrel.

GrizG · « **Reply #12 on:** December 06, 2022, 08:11:35 PM »

I've cleaned a lot of old tools, machine parts, and some gun parts with electrolysis... It removes the rust without causing further damage to the base metal and it is self limiting... rust gone-process stops.

I bought a power supply on Amazon for this use as my battery charger is "smart" and shuts off because the "battery" is bad. Arm & Hammer Washing Soda serves at the electrolyte and is available in the laundry isle. I use cans (big cans from kidney beans in particular) as the sacrificial anode. For long parts I use multiple cans daisy chained together with jumpers. Any plastic tray or bucket will work... for a long barrel a child's swimming pool would work. A wooden trough lined with plastic would work too. After the process stops I card the surface with a stiff brass brush and rinse with clear water. Then immediately spray with WD-40 to displace the water and prevent flashing.

The electrolyte solution is soapy water so you don't have to worry about hazardous chemicals.

M. E. Pering · « **Reply #13 on:** December 07, 2022, 08:29:45 AM »

This is probably not going to be believed, but here goes...

I was once loaned a muzzleloader percussion, that was extremely rusty, inside and out. I think it may have been a Thomson Center, but am really not sure. But the barrel was a Jukar made in Spain, that I do know. This rifle was worn out. Shoving a ball down the barrel was an experience, since in some places it was tight, and in others, almost fell down the barrel. It was obvious it had been not properly cleaned in years of use.

When I first got it, and shot about 20 rounds through it for practice, I swore I would declare the barrel unsafe, just because of the feel of the ball going down the barrel. However... The more I shot it, the better the accuracy got. It still doesn't make sense to me that such a rusty, pitted barrel should have any accuracy. Yet it did. In fact, I used that gun exclusively for over a year of hunting rabbits, taking many with head shots at over 50 yards.

But toward the end of that year, the barrel really started to show it's level of neglect. I always cleaned it after every shoot, but I think I was finally getting the crud out of it... lol. But it shot great until the time I returned it to the owner, and told him not to shoot it... I needs a new barrel.

My point is, don't give up on a pitted barrel... Try shooting it first. See how it reacts. See if it is consistent. A lot of times, we are seeking perfection where we should be seeking satisfaction instead.

Fly Navy · « **Reply #14 on:** December 07, 2022, 08:47:39 AM »

Another vote for Evaporust. This stuff really works.

GrizG · « **Reply #15 on:** December 07, 2022, 09:33:54 AM »

Quote from: M. E. Pering on December 07, 2022, 08:29:45 AM

My point is, don't give up on a pitted barrel... Try shooting it first. See how it reacts. See if it is consistent. A lot of times, we are seeking perfection where we should be seeking satisfaction instead.

Good point that last one... and our conception of perfection may not be right either!

rich pierce · « **Reply #16 on:** December 07, 2022, 04:14:18 PM »

A build is a big investment. It’s one thing not giving up on a pitted barrel on a built gun. Another thing building a new gun with a pitted barrel.

oldtravler61 · « **Reply #17 on:** December 07, 2022, 05:57:13 PM »

Follow Don and T.O.F. on the Evaporust. I have used it on three fully rusted barrels. Plus other parts. It works wonders...

P.W.Berkuta · « **Reply #18 on:** December 07, 2022, 07:36:27 PM »

If it was mine and I did not want to buy a new barrel I would first put it in a PVC tube seal one end and fill the tube with Evaporust to get the rust off. I would then send it off to Bobby Hoyt for a rebore. I would then have a NEW barrel

.

Daryl · « **Reply #19 on:** December 07, 2022, 10:34:32 PM »

That sounds like a perfect solution to me.

Dphariss · « **Reply #20 on:** December 08, 2022, 06:02:40 PM »

Quote from: Ravenshurst on December 06, 2022, 10:19:26 AM

Hi all
Not sure if this is the right place for this...
A friend of mine buys the contents of not-paid-for storage sheds....
Yeah. I know. But it's true.
So, he gave me a seriously rusted barrel, and a pre carved stock. The barrel is 36 inches long, marked .50 caliber, straight 7/8 across the flats, and marked with an 'M' inside a circle. According to the 'net this is a Green Mountain 1:70. barrel. It is kinda rusted/ sorta patine'd on the outside. The bore actually looks surprisingly good, mostly. I think I can clean most of it up....BUT...the first few inches of the muzzle are REALLY rusted, badly built up. Does anyone have any advice on cleaning up this barrel? Or should I just cut it down to 30 inches? Or just throw it away? Any advice would be appreciated. Thanks.

I would either fresh it or cut it off. 7/8 is not large enough to have cut out to 54 IMO. So freshing is the best choice or cut it to 30-32”. Assuming the rest of the bore it pit free. Coning will not solve the problem. If its pitted it will foul excessively and be hard to clean. If its rusted to the point of built up rust its not going to be fixed by any sort of lapping either. Freshing is a lot of work. And it may be pitted so deep that freshing done right is going to be just that much more work.

Ravenshurst · « **Reply #21 on:** December 08, 2022, 06:17:32 PM »

I don't have any idea how much it costs to have a barrel 'freshed, but I can't imagine it is cheap. If evaporust won't do it, or if the barrel is badly pitted after cleaning, I will just buy a barrel. This isn't the type of rifle I wanted to build anyway, it' just free. If it could be bored to .54, maybe....then again maybe not....but I don't think it can be. So, if it can't be saved, back to mt original plan. Thanks so much for all the great advice, Gentlemen.

New idea...if it can't be saved, maybe have it bored later for a small bore smoothie...

longcruise · « **Reply #22 on:** December 08, 2022, 06:30:56 PM »

Quote from: Ravenshurst on December 08, 2022, 06:17:32 PM

I don't have any idea how much it costs to have a barrel 'fresher, but I can't imagine it is cheap. If vapors won't do it, or if the barrel is badly pitted after cleaning, I will just buy a barrel. This isn't the type of rifle I wanted to build anyway, it' just free. If it could be bored to .54, maybe....then again maybe not....but I don't think it can be. So, if it can't be saved, back to mt original plan. Thanks so much for all the great advice, Gentlemen.

New idea...if it can't be saved, maybe have it bored later for a small bore smoothie...

It can also be relined. Not suggesting it, just noting.

rich pierce · « **Reply #23 on:** December 08, 2022, 06:33:57 PM »

A light freshing is the best route. 2 to 3 thousandths of an inch and it will be clean and shiny. Probably load better than a new barrel.

But I’d count the cost of a brand new perfect barrel that really fits my plan for my next build to a “let’s see if we can fix up this barrel and build something from it” approach to a new build.

oldtravler61 · « **Reply #24 on:** December 08, 2022, 06:40:51 PM »

You could make a few pistol barrels out of it. Just a thought

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Author Topic: clean up rusted barrel? (Read 3567 times)