Humidity too low

[berettaprofessor]

Over the years, I've seen the humidity in my gun safe steadily go lower, from consistently around 36% at the beginning to now about 27%. I use the renewable Remington dry packs that plug into a wall and have to reenergize them about every 3-4 months. Since the ambient temperature in the room is only around 61F (basement), I'm surely not worried about rust, but as it goes lower I'm starting to worry about getting the wood stocks TOO dry and causing cracking.

So, anybody out there with any info or experience on the matter?. Any cracked stocks from drying? Any museum-associated curator types out there on TheHighRoad?

 

[Reloadron]

From your friends at the NRA National Firearms Museum.

The low 61 degree temperature will contribute to the low humidity. Actually I see no need for the dry packs or desiccant packs. The link will cover the optimal suggested environment. While I have personally experienced problems I have never had my relative humidity that low.

Ron

 

[lilguy]

I've asked this question before, heard nothing but crickets. My gun room humidity varies widely. This time of year it stays 76 degrees, 16% humidity.

Summer with a dehumidifier same temp about 30% humidity. I have no wood problems but need to oil guns periodically to protect against corrosion.


I live in an old home and would love stable climate control, but cost is prohibitive.

 

[berettaprofessor]

Thanks Reloadron, hadn't seen that before. I've seen an online dewpoint calculator (maybe here on THR) that takes into effect both temperature and humidity for preservation but it didn't help me on the wood.

Looks like my relative humidity is too low. On the plus side, temperature in the storage area doesn't vary much, ranging from around 60 in the depths of winter to 66 in the summer. That may be why I haven't seen cracks yet.

Going to let the humidity come up a little.

The dew point calculator, for those who haven't seen it, is here: http://www.dpcalc.org/

 

[Reloadron]

I've asked this question before, heard nothing but crickets. My gun room humidity varies widely. This time of year it stays 76 degrees, 16% humidity.

Summer with a dehumidifier same temp about 30% humidity. I have no wood problems but need to oil guns periodically to protect against corrosion.


I live in an old home and would love stable climate control, but cost is prohibitive.

The line of questioning has come up numerous times in the forums. Obviously the average individual can't begin to afford a museum quality complete environmental control system.

Removing humidity or to dehumidify has several options, berettaprofessor mentions:

I use the renewable Remington dry packs that plug into a wall and have to re-energize them about every 3-4 months.

Silica gel is the most popular desiccant material. It works best when relative humidity is higher than 40%. What needs understood when using silica gel desiccant packs is that the desiccant will reach a saturation point. Thus the 40% number. Simply means that using desiccant packs with silica will not get the relative humidity below 40%. That said if the ambient RH is below 40% they do nothing. If we want a lower RH we need to go with a different type desiccant. In the case of berettaprofessor the desiccant packets are likely doing nothing right now.

Indicating silica gel changes from blue to pink when it has absorbed 8% of its weight. Bags have a window for monitoring color change.

Low-humidity molecular sieve is more effective than other desiccants when relative humidity is below 40% or temperatures exceed 77° F.

Clay is our most economical desiccant per ounce.

Anhydrous calcium sulfate is suitable for large spaces.

All depends on what you want or need. All of the above methods to suck moisture out of the air are Chemical Dehydration.

Another method is Reducing Temperature to Dry Air which normally use some form of refrigeration. We have all seen household dehumidifiers.

The list goes on as to ways and methods. You select a method based on your situation.

On the other end we have a need for humidity and humidifiers come in all flavors just like dehumidifiers.

Simple and free would be to fill a few bowls with water and set them around the house. If you have forced hot air heating in the winters then place a towel as a wick in a bucket of water in front of the ducts. Take showers and leave the bathroom door ajar.

Buy a ultrasonic humidifier. Boil water on the stove.

Yes, if the RH is low enough you run the risk of cracking or splitting a stock as the wood expands and contracts with temperature changes. If you need or want a controlled environment then you need to devise a plan to implement it. The simplest are basic home humidifiers or dehumidifiers which can be purchased at any home improvement store.

Ron

 

[Reloadron]

Thanks Reloadron, hadn't seen that before. I've seen an online dewpoint calculator (maybe here on THR) that takes into effect both temperature and humidity for preservation but it didn't help me on the wood.

Looks like my relative humidity is too low. On the plus side, temperature in the storage area doesn't vary much, ranging from around 60 in the depths of winter to 66 in the summer. That may be why I haven't seen cracks yet.

Going to let the humidity come up a little.

The dew point calculator, for those who haven't seen it, is here: http://www.dpcalc.org/

You posted while I was typing. I sure type slow.

Looks like my relative humidity is too low. On the plus side, temperature in the storage area doesn't vary much, ranging from around 60 in the depths of winter to 66 in the summer. That may be why I haven't seen cracks yet.

That would be my best guess. Temperature change, especially a rapid temperature change is the enemy of wood, especially dry wood.

Ron

 

[Mike1234567]

I just made another million dollars... I'll invent a humidistatically controlled device that automatically covers and uncovers exposure to dry packs.

 

[Reloadron]

I just made another million dollars... I'll invent a humidistatically controlled device that automatically covers and uncovers exposure to dry packs.

Why not dry packs and wet packs? When the air is wet remove water, when the air is dry add water? At least a million. Maybe even more. Think of the possibilities.

Ron

 

[Mike1234567]

^^^ I'll sell my idea to you for a measly $100K.

 

[ClarkEMyers]

How are you measuring the humidity? If it's a cheap dial that depends more or less on a thread stretching have you calibrated the dial with a sling psychrometer or otherwise?

My experience for what it's worth is that cycling humidity will warp and crack wood in a short order. My experience is also that a fairly constant humidity of any given level won't hurt BUT cycling from low to high as in the proverbial trip to coastal Alaska can really warp a stock as the wood grows and cycling from high to low will crack things as the wood shrinks. I've certainly had stocks with humidity in the teens and single digits with no issues except when going from low to high.

 

[MCMXI]

This time of year it stays 76 degrees, 16% humidity.

Summer with a dehumidifier same temp about 30% humidity. I have no wood problems but need to oil guns periodically to protect against corrosion

If the RH varies between 16% and 30% why are you experiencing corrosion? 30% RH is still very low.

 

[rcmodel]

According to the NRA National Firearms Museum?

70 degrees at 50% humidity is ideal storage conditions.

I'd lose the electric silica jell and strive for that.
Wood shrinkage / cracks is surely a concern at your present humidity level.

http://www.nramuseum.org/media/940963/conservationinfo.pdf

rc

 

[MCMXI]

70 degrees at 50% humidity is ideal storage conditions

I wouldn't obsess with the temperature but 50% RH is good advice. Corrosion rate is a function of temperature so colder is better.

 

[Mike1234567]

If you seal items off and remove the oxygen then there is no corrosion regardless of temperature or humidity extremes.

 

[MCMXI]

If you seal items off and remove the oxygen then there is no corrosion regardless of temperature or humidity extremes.

Corrosion can still occur in deaerated solutions where the reaction at the cathode is hydrogen reduction rather than oxygen reduction.

 

[Mike1234567]

^^^ Never heard of that. I'll investigate.

 

[primalmu]

Honestly, based on my experience with guitars (both owning and building them), here is my opinion:

I would hope that wood used for stocks are properly kiln dried. If the wood is properly sealed and it isn't exposed to EXTREME swings in temperature and humidity, I don't think you'll have a problem. That's not to say there isn't a chance of wood cracking, but what I said pretty much holds true for guitars, and I can assure you that a wooden guitar neck is MUCH more susceptible to humidity changes than a rifle stock.

 

[Mike1234567]

Honestly, based on my experience with guitars (both owning and building them), here is my opinion:

I would hope that wood used for stocks are properly kiln dried. If the wood is properly sealed and it isn't exposed to EXTREME swings in temperature and humidity, I don't think you'll have a problem. That's not to say there isn't a chance of wood cracking, but what I said pretty much holds true for guitars, and I can assure you that a wooden guitar neck is MUCH more susceptible to humidity changes than a rifle stock.

Are the inner surfaces of guitars sealed?

 

[Malamute]

I live in a pretty dry climate, humidity levels of 10-15% aren't uncommon at times in the summer, and when I'm using the woodstove for heat in the winter. The average isn't real high compared to many places. I've taken guns from the Midwest to very dry climates and never had any cracking whatsoever. They do loosen up some from shrinkage. Fore ends on lever guns get loose enough to notice, I ignore them, if they end up in a more humid environment, there needs to be some room to grow.

 

[astra600]

My area is normally 5%-8% humidity. My garage is kept close to 55* during the winter and 85* during summer. I use a swamp cooler during the summer in the garage, The guns are kept in steel gun cabinets in the garage. For 30 years now, I have had only slight surface rust on one tool directly in line with the swamper. I have yet to see any cracks or warps in my rifle stocks, most of which are milsurps. I expect the wood has cured by now. I guess I'm lucky in my situation. Our yearly rain is about 4", too. Been as low as 2".

 

[torqem]

If you coat the guns with car wax, rust will be a thing of the past.

 

[rcmodel]

The problems occure when you take the dried out stock from the dried out gun cabinet and go hunting or shooting in normal high humidity.

Say you get caught in the rain or fog or something?

That dry wood is going to suck up mosture like a spong, then swell.
Then back in the dry safe when you get home and shrink back up.

Better to start out at a more normal 50% in the wood, then it won't be a spond every time it gets a chance at getting a drink.

rc

 

[Queen_of_Thunder]

Clean the wood and use a lemon oil on the wood.

 

[primalmu]

Are the inner surfaces of guitars sealed?

Acoustic guitars, no (and they are certainly more vulnerable to damage related to humidity). However, solid body electric guitars are, for the most part, completely sealed (with finishes ranging from clear coat to tung oil or linseed oil). My comments were directed towards comparing rifle stocks to electric guitars since they are most similar.