Humidity Level

What is the proper relative humidity level for a gunsafe? I have a Liberty Centurion 17 ( a relatively small safe ) in my garage. I realize it's not the best situation, but it is what it is. I have two 750 gram gel cans and a remington plastic cased dehumidfier in it and I can't seem to get the level below 50%. This seems way too high and I'm open to suggestions for reducing it. Should I try weather stripping on the door, inboard of the fire seal, or do I just keep adding desiccant? Any advice?

If you dont have rust forming, then you have it low enough.

Firearms museums keep their displays at 50%RH and 70*F.

Snop, nothing's been in it long enough to rust, but that sounds like the equivalent of the "idiot light" on the dashboard that tells you you're low on oil as the engine is seizing I mean the idea that one day your XYZ with high polish bluing is fine, and a week later it's more pitted than the face of the kid behind the McDonalds counter really makes my teeth hurt!

GR, the temps inside the safe range from 60 degrees at night to 75~80 during summer days. Sometimes I open the safe and watch as the outside air starts dropping the humidity by 3~4 points. I haven't seen actual condensation, perhaps the temp of the items in the safe is higher than the air rushing in.
I was wondering if the in-safe heaters (goldenrod, etc.) would help me or if they're only useful in a situation where the ambient temp is stable (inside a house) so they can maintain a slight temperature elevation.

It only takes a few days for rust to form. If the stuff has been in there for 3 days, you would know if you have a problem.

Are you keeping them oiled up?

50% sounds ideal.

That is where mine stays +/- 5%, depending on the outside temp, & I've never had any problems with rust.

How does temperature affect the equation?

My new (second) safe is in the garage and it's damn hot in there in the summer. It's been 5 days, humidity is staying around 50% in the safe, but air temp in the safe is in the high 80s and maybe 90s at its peak. I haven't noticed anything rusting yet. My tools in the garage don't get rust, so it should be okay? I guess I will put everything on a more agressive oiling schedule, I've been spoiled with relative low humidity here in north Texas, and constant AC use in the house.

I don't know, I've just noticed when the temp is higher or lower the humidity level changes a little.

I have this chart tacked to the inside my safe door.

http://docs.engineeringtoolbox.com/documents/816/psychrometric_chart_29inHg.pdf

That chart gave me a headache


ETA: I have a dumb question; My safe has a doohickey inside it that tells me the humidity inside the safe, so is that the relative humidity inside the safe or does it also depend on the temp inside the safe???

That's the relative humidity, but it's a strong function of temperature. If you raise the temperature inside a safe, the relative humidity will decrease. Keep in mind, the absolute humidity hasn't changed, but the degree of saturation has.

Going by memory, say my basement is 67ºF / 60%RH. If I can raise the temperature inside my safe to 75ºF, the relative humidity should decrease to around just below 50%RH.

[chart of headaches: find 67ºF on the x-axis (dry bulb temp, ºF); go straight up until you hit the 60%RH curve; now move to the right along a line of constant absolute humidity (right y-axis, humidity ratio, gr/lb) until you reach the 75ºF mark; you should then be near ~46%RH (not quite half way between the 50% and 40% RH curves)]

Take a small cup of sugar and place it in the safe. Check the cup after a couple of days in the safe. If the sugar "clumps" up in the cup, you probably have a moisture issue.

As for a 50% RH level, most homes even with the AC running to maintain a comfortable temp. will push 50% RH anyways. People tend to forget that cooling the air with a standard HVAC system can actually put moisture in the air.

Found a helpful little calculator: http://einstein.atmos.colostate.edu/~mcnoldy/Humidity.html

My goldenrod and desicant equipped safe is at 82 degrees F and 60% humidity. According to this little calculator tool the temp inside the safe would have to be 66.72 degrees or cooler for condensation to form.

Mine said dew point 54F

I am extreamly confused on the issue now.

I have my safe in the house. Temp stays between 74-78 inside and RH is around 45 Is this ok?

Had a few flakes of rust on a scope mount and not sure why?

Sounds to me like you need to put a goldenrod in your safe to bump the temp inside the safe up a bit.

Is a goldenrod in a Stack-On cabinet useful?

We have been having a humid summer here in washington. I have a golden rod in my safe, and an Eva Dry. Right now with the Eva Dry out the safe is 56% humidity. With it inside, its about 54% humidity. I still dont have any rust forming on anything. The safe is out in the garage.

It's been a month now and no problems. I have an Eva-Dry 500, haven't put the goldenrod in yet. Daytime peak temps are in low 90s, but humidity has declined to about 41% with the Eva-Dry working and me not in and out of it so much after loading it.

my friend has a safe in his garage (in Houston, very humid there) and he has a golden rod in it and he does not have any issues. I was very surprised.

he shows 54% in the safe

I live in South Florida and deal with high humidity all the time. I can tell you from things rusting out that 45%-50% is ideal at 70-80 degrees. If you go to low you risk drying out any wood. It sucks to have a nice old gun get rust on it because your level is 55-60%.

I always assumed lower humidity was better.

So I have a safe, 70F in the house, 50% house humidity with 55-60% humidity in the safe. I've got a EVA-DRI 500 in there, no apparent difference in lowering the humidity.

I cannot easily put in a heated rod because there is no hole in the side of the safe, and no nearby plug anyways (a rather minor issue really compared to the lack of a hole). I'm reluctant to drill a hole in the side of my Sturdy Safe.

Luckily all my guns are non-blued, but I still don't want to risk rust.

I open the safe daily to take things in and out if that helps.

Any ideas as to how to lower the humidity some more?

Too low and you start to have issues with wood stock guns cracking.
My safe stays between 44-50% and I do not have rust.

Mine is usually 42%-45% and I don't have rust either.

Copyright © 1996 - 2013 :: AR15.Com LLC :: All Rights Reserved.
Any use of this content without express written consent is prohibited.