Ideal humidity level

Joined
Jul 23, 2005
Messages
33,307
Reaction score
60,043
Location
NC
What's the ideal humidity level for the basement area? I've been keeping my longarms down there with a dehumidifier set at 55%, and also "goldenrods" inside the safes.
 
Register to hide this ad
I believe museums strive for 50% humidity and 70 degrees F., but maintaining relatively consistent temperature and humidity is more important than hitting exact numbers. Too dry can damage wood.
 
The Curator at the Springfield Armory did an article on caring for firearms a few years ago. Unfortunately, it seems the NPS has taken it off their site(probably Bush's fault:eek:). Anyway, in it he recommends 40 - 50% but says consistency is far more important that what the RH is.

Bob
 
My basement is my gun workshop and storage for many of my long guns and a few handguns. I also have a small lathe, drill press, belt/disk sander and a number of other tools that I don't want to rust. Before I installed a dehumidifier, humidity would fluctuate from 50-80+% and my tools would rust. After the dehumidifier was installed and set to 45% my rust problem disappeared and I was able to keep guns there with no rust problem. Sealing the basement walls with Dryloc and sealing the concrete floor with a commercial sealer, helped a bunch. The dehumidifier doesn't work nearly as hard to maintain the 45% level after sealing the walls and floor.
 
55% humidity? Isn't that what you get up your nose 30 seconds after falling in Lake Mead? :p The humidity here has been less than 10% for several days with a hairdryer wind on top. We are all complaining about dry eyes, bleeding sinuses and mongo allergies, even the guys that don't have allergies.

The low humidity here is an issue for gun storage. I bought a Chilean Mauser locally a couple of years ago and the stock was dry like an old piece of creosote bush. The first few times I coated it with BLO the stuff soaked in in the time it took me to refresh the pad I was using for application.
 
Last edited by a moderator:
I keep dehumidifiers running in both my basement and garage workroom.
One caution on the % you select, if the temperature is variable in the space you are trying to control, the %RH will increase when the T goes down and increase when T goes up. Metal objects will change T much more slowly than the air.
In a T & RH controlled environment 40-50% may be a good target. They have big AC units to keep change to a minimum. For me at least, if I want to avoid rust I must control to a lower % to avoid RH increases when the T goes down.
The basement is about 30% right now because the temp has slowly raised not much circulation there. The garage runs 35-45 as it tries to keep up with temp changes.
It is all working fine, no rust on tool surfaces.
 
I keep dehumidifiers running in both my basement and garage workroom.
You have a basement in Inverness(or wherever you are over there).:confused: Man, I could have gondola racing down there year round if I tried to put a basement in over here.:eek::D

Bob
 
The Curator at the Springfield Armory did an article on caring for firearms a few years ago. Unfortunately, it seems the NPS has taken it off their site(probably Bush's fault:eek:). Anyway, in it he recommends 40 - 50% but says consistency is far more important that what the RH is.

Bob


Here is the pertinent part of the article by David Arnold, Conservator of the Springfield Armory NHS Museum:

• 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.
 
I guess this is why there are no museums in the south.
Ain't got nuthin' to put in no museum. We sell it all to Northurn turistes heded fer Flawdah. Thell by eenythin ol'.
I haf to refeel tha barn 2-3 times a weak...... Jus ack dum, an tell um it was Granpappy's. Helps ta ware overhalls- ya alwaze get mor.
;)
Gotta run, tha lanfeel gets hot aroun' noon, an tha convicks get slow bout lodin tha truck. :D
 
We wuz doin' real good w'ourn too. "Til we added duh stuffed Sipowicz dolls. Kild bizness. Nawthun turistes heah sayed thay made the place look cheap.


'At was dum.
Ya c'ain't sale a yankee a yankee.
Thay alreddy got zilyuns of em runnin round up thare.
:rolleyes:
 
Basements in Florida

I am on a part of the Central Ridge west of Inverness, the house elevation is about 90’. There is about 50 feet of sand above the rock here. You couldn’t pour water on the ground fast enough to make a puddle. There is a DRB about 20 feet downhill from here, water drains out as fast as it enters.
There are a few other basements around. The problem was finding someone with forms to pour it. The contractor was from Ocala, said he keeps busy.
I have a sump in the corner and made provisions for a pump but even in the hurricanes with water coming off the roof like Niagara Falls, no water in the sump.
Nice and quiet down here, temp stays about 78 all summer unless I direct a bit of AC down.
 
You want 55% humidity around here, you're talkin' misters, not dehumidifiers. Now that we're all taking credit for our important personal roles in advancing the anti-illegal immigration bill, you can't even find 55% humility...
 
Back
Top