A poorly constructed cache is as bad as no cache at all. In the past, partisan fighters in Europe and the Philippines buried guns and ammunition improperly. When the weapons were retrieved to fight invaders, rust and moisture had made them inoperable, and the fighters were forced to battle with weapons in poor condition or those retrieved from the enemy. Fortunately, several chemicals are available in most gun stores that will give added rust protection to the reloading equipment you cache. Outers' Metal Seal displaces water somewhat, adheres to the surface of steel, and acts as a lubricant as well. It's readily available at most gun stores and comes in an aerosol can, which makes application quick and easy. For maximum protection, cached tools can be encased in paraffin, Cosmoline, or other grease or wax combination to prevent rust formation. This sealing mixture can be improvised by melting candles and mixing them with a heavy oil, taking care not to set the mixture aflame. A heavy coat of motor grease or even Vaseline is a good alternative. For small metal items, you can buy Outers' Gun Grease, which is formulated for long-term storage of metal tools and guns and is also sold at most large gun stores. (Aluminum handles or other aluminum parts found on presses don't need to be covered with oil or grease, provided they are kept dry, but all steel parts do.) Before storing any metal object, clean its surfaces and wear rubber or cloth gloves while cleaning and packing the tool in grease so sweat doesn't get onto the metal and promote rust. (This will also prevent your fingerprints from being on the object if it is discovered.) If you're caching reloading dies, be sure to pack the inside of the dies with grease; any rust here will severely damage the dies and perhaps even make them useless. If you're also putting firearms into the cache, two important areas to pack with grease during storage are the bolt and the bore. Be sure to coat the inside of the gun with grease as well as its exterior and cover the internal parts. Once the dies, guns, and whatever tools you're caching are packed in grease, place them in a heavy plastic bag. The thicker the plastic, the better; and the less air in it, the less chance there is that rust or tarnish will form. Ziploc bags are handy for die kits, but use several of them around each die to ensure the moisture seal around them. The very best caching container is Bianchi Blue, a bag treated inside with a blue chemical that absorbs moisture and prevents rust as well. This bag is big enough to accommodate a large handgun and will work with much of your reloading equipment — though not the entire press. These bags are available at most gun stores or can be ordered directly from Bianchi International. If you're pressed for time, simply force out the air in the bag with your hand and seal the bag. If you have more time, you can remove the air from a bag more thoroughly. One way is to use a small hand pump like that used to remove air from food containers. These are often available at health food stores and work well if you take a towel or other object to seal the plastic around the hose. You can also use water pressure to get the air out of a plastic bag (a method apparently conceived by Ragnar Benson — at least he's the first guy I know of to propose it~. To do this, a bathtub or other container of water is required. Keeping the opening of the plastic bag well above the water, lower the bag into the water; the pressure of the water forces the air out of the bag. Then very carefully seal the opening and pull the bag from the water. Let it dry thoroughly before caching. Failure to let it dry completely will result in high humidity and rust inside the cache chamber . Be sure the bag you're caching is sealed tightly. Ziploc-style fasteners are often not sealed completely, which allows air and moisture to flow in and out of them. Take extra care to double-check the seal . Once the bags of equipment are sealed, they should go into a rugged container that will protect them from accidental breakage and prevent tearing of the plastic bags. This container will also help keep moisture out and protect the materials in the cache from insects and vermin. There are two types of containers used in caching: an airtight container and an porous one that allows air movement through it. Although it seems like the porous container would promote rust, in fact it is sometimes a better choice, especially in dry areas, because it prevents moisture from accumulating inside the container. If your cache will be in an arid area, a porous container is better. The porous cache box can be constructed of any type of wood, but exterior plywood is best. Use galvanized screws or nails to fasten the box together (regular nails or screws will rust, and the box will fall apart eventually) . After the box is finished, paint it inside and out with urethane or spar varnish. The watertight container is essential in humid areas. If a watertight cache is created, then it's necessary to place a hygroscopic chemical packet inside the container, away from the firearm or other metal tools. Silica gel is the hygroscopic chemical of choice and is available at most drugstores.