Having addressed safe and responsible gun storage, I will now address the importance of protecting your guns from damage due to humidity.
Modern firearms are incredibly well engineered devices that stand up to the stresses of being fired time and time again. They easily resist the thousands of pounds per square inch (PSI) of pressure that is generated when the gun powder burns to propel a projectile down the barrel and on toward its target. Despite this strength and durability, guns are susceptible to damage from moisture. For that reason, gun owners will want to store their guns in a dry location. Yet storage inside a gun safe, which is arguably the best place to store guns, can lead to condensation due to temperature changes and a lack of airflow. Luckily, this problem is relatively easy and inexpensive to solve, and the end result is a gun storage environment that keeps your guns secure from theft and protected against humidity-caused damage. Various methods for combating humidity are discussed below:
1. A Dehumidifying Wand/Bar
These devices often sell for well under $50 and are basically small heaters designed to be mounted near the bottom of a gun safe. They draw just a few watts of energy and warm the air, which causes small amounts of air flow in order to keep moisture from building up inside the safe. They also raise the temperature of the safe’s contents by a few degrees, helping to prevent condensation from forming within the safe. These are quite effective, and most firearm safes will have a very small hole near the back through which the power cord can fit.
2. Desiccant (Moisture Absorbing) Devices
These are the the small pouches found in new shoes and clothes, which absorb moisture. Larger versions are available which can hold about a cup or more of moisture, for about $3. They last for several months during the summer, and easily last through the whole winter (in colder climate zones). I use a couple of these larger desiccant devices in my gun safe, and in the closet that contains the gun safe. Since I keep ammunition stored in a smaller safe within my large safe, I also place the desiccants into the smaller safe.
3. A Standard Dehumidifier
An electronic dehumidifier, which is similar in principle to an air conditioner, can be purchased for upwards of $100. Unless your gun safe is actually a walk in room, this would be best placed in the room or closet which houses the gun safe. The two options discussed above should be more than sufficient, but if you live in a particularly humid climate and have a walk in gun safe then this option may be better for you.
To keep my large gun safe dehumidified, I use a dehumidifying wand mounted on the inside of the safe near the floor, and I use a couple of these larger desiccant devices in my gun safe, and in the closet that contains the gun safe. Since I keep ammunition stored in a smaller safe within my large safe, I also place the desiccants into the smaller safe. I have to change the desiccant devices a few times a year, for a total cost of about $12. The Dehumidifying wand uses about $3 of electricity a year, and the net result is that my guns are keep dry and free of rust.
You didn't mention what humidity level is appropriate!
50 is optimal not over 60
Ralph:
Generally speaking, the problem will be too much moisture, rather than too little, so I only addressed the removal of moisture from the gun safe.
The optimal humidity level is one of those questions where 10 people will give you 10 different answers. It also matters what materials your guns are made from (for example, very low humidity can damage wood stocks but generally won't harm guns with plastic stocks.)
That said, it seems that a humidity level between 25% and 65% is optimal.
I have a dehumidifier and a Heater in safe but get what looks like a white powder on leather and plastics. is that moisture or chemical like from oil