[Rooinek]

I have about a dozen or so cannon-balls. These are primarily 19th century and were recovered from land not sea. They are all in fair condition but have a coat of rust. What do I need to do to stabilize and display?

Example in the photo came out of the Poltava Battlefield and was recovered decades ago.

 

[WolfmanReid]

That dark rust is quite stable as is. If you really wanted to get crazy with it you could scrub it with a rust remover and then paint with black rustoleum to protect it (which is more or less how 18th/19th sailors protected cannonballs) I wouldn’t bother though you are dealing with a solid cast iron ball that will long outlast you in its current state.

 

[BlackPowderBurner]

Make sure it's solid shot first, boil in distilled water for a couple hours then allow to dry. Scrub with fine steel or bronze wool to remove powdery rust and scale. Once clean, let it cook in some melted paraffin wax then buff down the wax till you get the desired look. It should come out nice and black without active rust.

 

[bodes]

Unless you are trying to preserve original finish or markings, the one pictured has already suffered through the ravages of time and the elements....As stated, it appears stable so a minimal amount of maintenance is all that would be required....You might want to just daub on some cheap motor oil or spray on some WD-40 periodically....This will leave a coat on it and give it a darkened appearance....Bodes

 

[shran]

Not sure why you would do anything to it...? Unless you're keeping your cannon balls buried in wet dirt or under the ocean it'll probably look just like that for a couple hundred more years at least. Might as well dig up Grandma and give her corpse a new coat of lipstick while you're at it.

 

[Nirvana]

Make sure it's solid shot first, boil in distilled water for a couple hours then allow to dry. Scrub with fine steel or bronze wool to remove powdery rust and scale. Once clean, let it cook in some melted paraffin wax then buff down the wax till you get the desired look. It should come out nice and black without active rust.

This is the correct answer. Melted wax.

 

[72 usmc]

A more academic perspective from an archaeological perspective:

Care and Cleaning of Iron – Canadian Conservation Institute (CCI) Notes 9/6 - Canada.ca

www.canada.ca

A looters perspective: Conservation of Iron Artifacts

If cheep and want a waxed look some museums use Renaissance Wax. A better quality coating. No shellac or varnish.

https://www.archivalmethods.com/downloadfiles/Renaissance-Wax.pdf

Amazon.com

A way to stablize rust surface see general : A Beginners’ Guide to Collecting and Restoration No 2;- Electrolytic Derusting – Antique Firearms Restoration Blog
See electrolysis : How To Derust Cannon Balls

or leave as is...

 

[bodes]

This is the correct answer. Melted wax.

WD-40 has paraffin (wax) in it....Bodes

WD-40 contents

 

[Clyde]

If it is inside in a climate that isn't humid (unlike mine - relative humidity today is 36% - lower than it often is - at 103 degrees Fahrenheit), I'd say leave it alone, it will (as others have noted) be stable as is.

 

[72 usmc]

I favor the "as found" patina, waxed artifacts look funny, painted worse. Oiled & stored in a glass case is OK, but outside of a case it really attracts dust and is a cleaning problem in dusty areas. After a year you got a fuzz ball.

 

[SfcRet]

yeah, I don't believe you have to anything to preserve an iron cannon ball, except to knock off the loose rust.

that cannon ball from the Poltava Battlefield is over 300 years old and will be around for another 300+ years in the same condition just as it is now without nothing being done to it

 

[Nirvana]

WD-40 has paraffin (wax) in it....Bodes

WD-40 contents

It also has a lot of VOCs and toxic stuff, and will leave a weeping mess for a while, staining whatever you sit it on.

 

[panzerfaust44]

It depends on HOW you want the artifact to look.

I collected Civil War artifacts for nearly 20 years, including artillery shells.

Some collectors use ELECTROLISIS which is used to remove the rust from the artifact. I have used this process on some dug WWII ordnance items including a German Panzerschreck rocket. The resulting finish is a medium grey metal color.


On solid shot or grape shot, I prefer the old rusty look. I would occasionally wipe them down with a rag with some Hoppes gun oil on it and that was it.

 

[fourbore]

Unless you are trying to preserve original finish or markings, the one pictured has already suffered through the ravages of time and the elements....As stated, it appears stable so a minimal amount of maintenance is all that would be required....You might want to just daub on some cheap motor oil or spray on some WD-40 periodically....This will leave a coat on it and give it a darkened appearance....Bodes

This echos my opinion, but; I will toss out CLP as another low cost easy to apply chemical. Kinda split the difference where oil is a bit thick and WD40 thin and too volatile for my liking. You can buy CLP in gallons now, although I dont use enough for that. I did find Lucas offers a CLP, so; for me that leaves a lot of BreakFree brand to use up.

Normal CLP's are good for a year and BreakFree now has a 5 year formula. If that matters.

I do have a couple big basket ball size cannon balls on my damp cellar floor. No coating at all. They seem like some kind of iron that does not rust like steel in the same environment. Nothing maybe all that is really needed. Or CLP my 2c.

 

[Essex]

I have several cannon shells and the best method I have found is to heat them in boiled linseed oil. I have an old hot plate that I put the pot on in the middle of the back yard.
The heat drives out the water and the oil replaces it. With out this treatment, If left sitting on the shelf the ball will slowly flake away.

 

[Clyde]

I have several cannon shells and the best method I have found is to heat them in boiled linseed oil. I have an old hot plate that I put the pot on in the middle of the back yard.
The heat drives out the water and the oil replaces it. With out this treatment, If left sitting on the shelf the ball will slowly flake away.

I think that would be fine for solid shot (including grape), but not for shell, not unless I was certain they were well and truly emptied. In that day, shell would normally have had a bursting charge of black powder and heating that can get - exciting...

 

[Orcutt]

I spray mine with Eezox it darkens it up and am happy with it.

 

[Claypipe]

WD-40 has paraffin (wax) in it....Bodes

WD-40 contents

WD40 will turn it into a moisture sponge. Better to let it set a week or more in 90w oil out in direct sunlight, this will turn the rust into a protective coating.

 

[fourbore]

I despise the BLO treatment

 

[Murdock]

A more academic perspective from an archaeological perspective:

Care and Cleaning of Iron – Canadian Conservation Institute (CCI) Notes 9/6 - Canada.ca

www.canada.ca

A looters perspective: Conservation of Iron Artifacts

If cheep and want a waxed look some museums use Renaissance Wax. A better quality coating. No shellac or varnish.

https://www.archivalmethods.com/downloadfiles/Renaissance-Wax.pdf

Amazon.com

A way to stablize rust surface see general : A Beginners’ Guide to Collecting and Restoration No 2;- Electrolytic Derusting – Antique Firearms Restoration Blog
See electrolysis : How To Derust Cannon Balls

or leave as is...

Not meaning to be more than just informative---Renaissance wax may be good for some but I had a bunch of knives (hand forged) rust overnight with its protection. Never again, for me.