Dehumidifiers

[reloadem]

Do you leave them on all year, or just the wet months?

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[OFADAN]

24/7/365...never goes off - ever.

 

[KENOC]

All year, but set it to 50% humidity, so obviously will run much less in the drier months...

 

[A2theK]

Mine's set at 55 F 35% all year

Is 50% too high or 35% too low?

I know museums and the Smithsonian say the lower humidity the better. (..or at least I thought that I read that somewhere - I don't have any Mother of Pearl or Ivory grips to crack at the lower humidity levels)

 

[Sun195]

Is it possible to over-dry your wood stocks with one of these?

 

[A2theK]

Is it possible to over-dry your wood stocks with one of these?

That's what I was wondering. I have an article somewhere. Let me find it.

Kenoc is closer to the correct % I may need to up mine a bit.


Preserving Your Antique Arms Collection

The following are very conservative guidelines to help you care for a collection that you wish to preserve for as long as possible and will never be fired. It represents the safest, most conservative advice I can give without thoroughly examining your collection. Methods recommended here may not be the most efficient. There are many more treatment options available to me which I cannot share in this forum. What may work beautifully in one situation can be a disaster in another. I treat every gun as a unique object and the treatments I perform can vary considerably from what follows. The following advice is limited in scope and cannot cover every possible situation. It is based on my training and experiences as a conservator, and my experience working (so far) mainly with military firearms made during the last three centuries. I continue to learn more with every treatment I do. As a consequence, these guidelines are a work-in-progress, and I am interested in any comments or questions you may have. Feel free to contact me with your questions or concerns. By doing so you will contribute to the improvement of these guidelines. David Arnold, Conservator, Springfield Armory NHS Museum.

A. Preventive Care

1. Environment ·

* Avoid dramatic swings in relative humidity (RH). Try to keep stable between 40 and 50%.
* Consistency is more important than precise maintenance of a specific RH reading.
* RH control is most critical because of an unusual physical property of wood called anisotropy. Wood cells expand or contract very differently in response to changes in relative humidity -- depending on their specific grain orientation (axial, transverse, or radial) in the log from which they came. Large swings in RH can result in cracks caused by compression-set shrinkage.
* If humidity remains fairly constant, changes in temperature make little difference to either metal or wood – better to concentrate on controlling relative humidity. A rapid rise in indoor temperature can pull the moisture out of the environment (including your artifact), causing a drop in RH. Cell shrinkage and cracking or splitting can occur.

2. Handling

* Wear gloves when handling your collection. No protective coating – appropriate for conserving an artifact -- (see below) can stand up for long against repeated bare-handed handling. Best thing is to always wear gloves. Nitrile examination gloves are recommended when cleaning and coating your collection. Once an item has been coated, wear plain cotton gloves.

3. Housekeeping

* Keep dust-free. Dust can trap moisture increasing the likelihood of corrosion occurring.
* Do not use commercial dust cloths. They often leave an oil film behind. Oil films trap dust. Dust traps and collects water vapor in the air.
* When dusting, use a soft cotton cloth very lightly dampened with water
* Without moisture, dust merely gets shoved around and will not be picked up.
* Do not use alcohol of any kind when dusting or cleaning a stock. It can skin or strip an historic finish.
* Dry immediately with a clean cloth.
* Never use liquid or spray dusting products. Most leave mineral oil behind, which traps dust. Dust traps and collects moisture. Starting to see a pattern?

4. Storage / Display

* Narrow hooks or loops of wire should not be used to support collection pieces either in storage or on display. The weight of most long arms on such devices is sufficient to result in indentations in their stock at the points of contact.
* Use broad, padded supports. We use thin sheets of a closed-cell Polyethylene foam material[ii] to pad our display fixtures.
* To avoid mold and mildew during long-term storage -- avoid at least two of the three conditions known to promote bloom outbreaks:
o elevated temperature
o still air, and
o elevated humidity.

B. Cleaning and Coating Historic Firearms

1. Cleaning Wood Stocks

* Separate wooden and metal parts. They are cleaned and coated differently.
* Unless absolutely necessary, leave unfinished interior wooden surfaces alone.
* Clean exterior of stock as follows:
o Use a few drops of a mild detergent[iii] in a gallon of warm, distilled water, applied with a slightly damp soft cloth, and rinsed with clean cloths dampened with distilled water.
o Dry with soft cloths immediately after rinsing.
o Clean again with mineral spirits, using a soft cloth to apply. Work in fresh air or a well-ventilated area.
o Avoid using "oil soaps" as they can becaustic and may damage an historic oiled surface.

2. Cleaning Barrels and Other Metal Parts. Please note: It is essential to practice any new technique on a sacrificial piece first, before applying it to something irreplaceable.

* Use nylon or animal-bristle bore brushes[iv]. Wherever possible, avoid using brass or steel brushes. Such hard materials can scratch, but also might (under certain conditions) cause galvanic (bi-metallic) corrosion (specifically when using a copper-alloy brush on ferrous metals) by leaving a slight metallic smear behind.
* Use mineral spirits to soften accretions. Work in fresh air or well-ventilated area. Are there other solvents that are "stronger"? Yes, but they are difficult to work with safely.
* Swab clean with a cloth patch.
* Use only extremely fine abrasives such as oi1-free 0000 steel wool[v] . Use only if absolutely necessary to remove stubborn rust deposits or other accretions. Work slowly and watch constantly for any changes to the surface. There is always an element of risk in such work. If you are at all uncertain, hire a conservator before causing irreversible damage.
* When cleaning brass parts, never use products that contain ammonia. Ammonia can damage old copper alloy materials by corroding them from from the inside out. In addition, such products may include abrasives which may prove too harsh. Elbow grease and mineral spirits should be tried first. If something slightly stronger is needed, try applying small amounts of wet tooth powder with a cotton swab and rinse with water.
* A general comment about commercial rust removers. To date, I have not found a rust-removal product which is entirely safe to use on historic metal surfaces. The problem is that most rust removers can't tell the difference between iron oxide and iron metal, and will leave an etched surface even where there is no rust. Some products seem to come close. Often they require extremely close attention and precision – too much for most of us. In short, there are no magic solutions which are risk-free and I advise against their use on anything you value.
* Most surface rust can be removed by first lubricating the area with a light penetrating oil[vi] and cleaving it off with a sharp scalpel held at a very low angle to the metal. It requires close attention, a steady hand, and some patience, but if you are careful, you will probably get most – if not all – of the surface rust off without leaving a scratch. When done, remove any remaining oil with mineral spirits.

3. Disassembly and Reassembly

* If you are organized and systematic -- you should be able to safely disassemble and reassemble most firearms successfully.
* Probe the floor of every external screw slot with a sharp point held at a very low angle. It's amazing how much dirt can be packed into a "clean-looking" slot. All foreign matter must be removed for the screwdriver to do its best, safest work. .[vii]
* A good selection of screwdrivers is a must. Their tips must be matched perfectly to each slot in order to maximize the area of mechanical contact. Taking this precaution will minimize slippage and the scratching and scarring that can result. The internal shapes of screw slots have changed a lot since their invention[viii] and screwdriver tips often have to be ground or filed in order to get a good match. Keep this in mind when regrinding a screwdriver's tip.
* There are many publications that offer exploded drawings and disassembly/reassembly tips[ix]. There is also a brilliant web site that illustrates with moving images how various types of firearms work[x].

4. Coating Stocks

* Wood is neither thirsty nor hungry. It is usually covered by a finish which may have become corrupted in some way, making it look "dry." The wood beneath the finish does not need to be "fed", (despite what wood-care product commercials may claim).
* Never put oil of any kind on an historic finish. There may well be unintended but permanently damaging consequences to ignoring this advice.

 

[reloadem]

You guys must have better dehumidifiers than me, mine doesn't have any adjustments. What are you using?

 

[A2theK]

$75 used Kenmore one it has a knob for "dryer" or "less dry" I have to empty the bucket every week. You must run a heater in front of it on low in the winter because Temp/humidity are related sort of or at least the ability to suck out the water.