Moisture can be an enemy to your firearms. Temperature changes can cause the metal parts of a gun, such as the receiver and barrel, to "sweat" which can result in surface rust or even rust that is corrosive. If you don't wipe the gun down to dry it, rust will form. You can avoid this type of problem by initiating some steps to keep the storage environment of your gun safe dry so your firearms will be protected.
Mount a dehumidifier bar or wand on the bottom part of the back wall of your gun case. Many manufacturers supply a universal bracket with the product. Your gun case will need to be equipped with an access hole in the back so that you can pull the electrical cord through and plug it into a receptacle. A dehumidifying bar functions as a small, low-watt heater that raises the temperature inside the gun safe and helps prohibit moisture from forming. It is designed to be left on all of the time.
Place one or two containers of dessicant in your gun safe. Dessicant absorbs moisture and is what is in the small packets placed in shoe boxes and new purses. Dessicant is available in different size containers and can be recycled in a warm oven once it absorbs moisture. Some manufacturers make dessicants that will change color once they absorb moisture to let you know they need to be recycled or replaced. Follow the manufacturer's recommendations for recycling the product.
Place a dehumidifier in the closet or area where your gun safe is located if you have a small safe. If you have a walk-in safe, place the dehumidifier inside of the vault. Run the dehumidifier for several hours each day to keep moisture levels down. This method works best in conjunction with the other products listed in this article.