Cleaning Plaster dust off guns?

[buckhorn_cortez]

Gypsum is calcium sulfate and is classified as a mineral. In its dry form it is not corrosive. However, once it gets wet or in the presence of high humidity it can corrode steel over time - mainly due to the fact it can retain moisture over a long period of time allowing the water to react with the steel.

Calcium sulfate is only slightly soluble in water. When it does dissolve, the ions are spectator ions. This means that they do not interact with water molecules in a way that significantly changes the pH. The pH of a saturated solution of calcium sulfate is 7.7, close to that of pure water.

Because gypsum starts as a crystal, as it breaks down it retains a crystalline form with sharp edges making it very abrasive

However, it should not be all that difficult to clean up. If they were my guns, I'd start with a rubber bulb duster like those used to clean sensors on digital cameras (Giotto Rocket Duster) to get the majority of the loose dust off, then I'd use a soft brush, like a lens brush or camel hair artist's brush and gently brush the dust off of the guns. Finally, I'd take canned air or compressed air at about 20 PSI and gently blow off the guns to get off anything missed with the other cleaning processes. Then lightly oil the guns as you would before storing them.

As part of the cleaning, check the bores and see if dust has gotten into the bores. If it has, swab out the bores with a dry patch and then with an oily patch and recheck to make sure you've gotten out all of the dust.

Honestly, gypsum isn't all that bad. People play on it all day long at White Sands, no one dies, cars don't instantly corrode into a pile of rust - it's actually rather benign.

Any type of corrosion takes prolonged exposure to damp gypsum over a number of years.

I'd worry more about the abrasive effects as NASA found out when they landed the Space Shuttle Columbia at the White Sands Space Harbor in March, 1982. The dust from landing on the dry gypsum lakebed got all over the interior of the Shuttle and they had to nearly disassemble the entire Shuttle to clean out the dust.

If you can clean an entire Space Shuttle that got gypsum dust in it at 200+ MPH - cleaning guns with gypsum dust that simply fell on them should be relatively easy.

 

[buckhorn_cortez]

I'm going to have to disagree on this. Gypsum is a LOT more corrosive than just plain dirt.

You'll have to explain how you define "corrosive." Soil can range naturally from a pH of 5.4 to 8.3 in some areas of Colorado and Texas. Since 7.0 is neutral pH, that means soil can be acidic to alkaline. Gypsum is 7.7 pH, or nearly neutral in pH.

How does gypsum become more corrosive than some soils?

I would also note that my Roto-Zip drywall tool is never cleaned of drywall dust and shows no corrosion on the metal parts like the collet, nut, shaft, or even the bits.

You'd think that if gypsum was corrosive, after 2.5 years of use, the Roto-Zip would show some kind of metal damage from constant contact with the gypsum dust. But, it doesn't. If I clean off the metal, it looks like new, including the unfinished, carbon steel parts like the collet and motor shaft.

Based on zero corrosion from gypsum dust on my drywall tools, I don't think that gypsum dust is corrosive in-and-of itself. Only when gypsum is moist does corrosion become a problem - but, that's from the oxygen in the water exchanging ions with the metal, and not from gypsum.

 

[Evan Thomas]

I think some people may be confusing "corrosive" with "abrasive." Corrosion is a chemical process, while abrasion is a mechanical one; while gypsum is somewhat corrosive, I'd be more concerned about damage from abrasion. I've never seen corrosion on a drill bit with plaster dust left on it, but I do know that drilling in plaster is a great way to wreck one. I'd never use one of my good woodworking bits to drill a hole in plaster or drywall.

My approach would be to vacuum first, to remove as much dust as possible without dragging it across surfaces, then clean as usual.

 

[briandg]

Some people are going to dive all over this as stupid, but have a little faith. If we're talking about simple firearms, bolt, revolver, easily disassembled, this idea really depends on how deeply you think the grit has penetrated.

Guns, and all metals, are waterproof, and won't be harmed with proper care. Strip the things down as far as you need to, get very heavy-duty dish soap, and sluice them as clean as you can get them with the hottest water you can use. Dry with rags and pat he's, then warm dry air, and oil every surface before you put it back together.

Every hunter has been caught in rain. Guns aren't hurt by water, they are harmed if they are left wet and dirty.u

 

[johnwilliamson062]

If it was me I'd remove individually from the room.
Vacuum or wipe off most of the debris(normal vacuum would probably be ok for this small amount)
Compressed air
Then, if I couldn't extensively clean each firearm I'd spray them with CLP and repeat the compressed air.
A full cleaning would be best IMO. I wouldn't want that gypsum in all my trigger groups.

 

[FITASC]

If you merely blow them off, then you'll have the dust everywhere in that room. Use a vacuum, then a cloth with a light coating of oil or similar to attract and retain on the rag anything left over from the vacuum. (Like you would dusting fine wood furniture)

 

[drobs]

I think we need a picture of the gun room...

 

[Snyper]

If you merely blow them off, then you'll have the dust everywhere in that room.

There's already dust all over the room.
A minute fraction of an ounce more wouldn't make any difference at all.
The smart thing would to be take them outside for any blowing.

 

[T. O'Heir]

"...high humidity it can corrode steel..." That's the humidity causing the corrosion. Steel being made man stuff and Ma Nature dislikes stuff that is man made. Rust is steel returning to its natural form.
Like Snyper says, suck or blow it off. Makes no difference. Like briandg says, gypsum, like water, isn't going to cause your firearms to rust instantly. Isn't going to do anything when it's dry either.
If your dry wall crumbles when stuff is drilled into it, something is terribly wrong. Start by sharpening your stuff.

 

[pappa]

A lot of varied opinions offered. Lot of ifs involved. If all the metal is completely free of lubricant (which I would think they aren't), then the dust would have nothing to stick to. In that case only an air blow may work.
Also, corrosion problems vary greatly with humidity. Someone in Colorado (often~15%) has much more time before need to worry than a person in Florida with 87-97% often.
Only question with corrosion is when, not if.
See ASTM article on Assessment and Remediation of Corrosive Drywall. www.astm.org/COMMIT/C1101-EdLightPresentation.pdf.pdf. . Simplest to just google "corrosive drywall". Lots of sources of info.
All my guns - no Cerrocote- have a thin film of oil for lubrication/corrosion resistance. I live in Florida and water wash (detergent too, if needed- depends on amount of lube in gun) is only way I have ever been able to remove windblown fine sand grit.
By the way, Columbia was an ORBITER. The Space Shuttle is 2 SRBs, 1 External Tank, and the orbiter. STS-xxx was different for each flight. To poster on this, I am just teasing - I knew what you meant. Brought back a lot of memories - used to build them. Gosh, 1982 was 34yrs ago! Almost half my life-76 , 2 more months. Stay cool, and again, I am just kidding about it. Pat

 

[buck460XVR]

It's just some dust on the guns.
It's not some hazardous substance.

Depends. If the plaster is from the 50s thru early 70s, and is really plaster, it may very well contain asbestos. If that is the case, the last thing you want to do is blow it into the air. Suck it up, don't blow it around, even if it's plain gypsum. Plaster dust is also very fine dust and can damage good vacuum cleaners. Use a shop vac. I'd vacuum what I could and then wipe down the guns as if I was cleaning them after hunting in the rain/mud.