Most freezers automatically defrost. That means they heat up (yes, your freezer actually has a heating coil built into it) and melt off any ice buildup on the walls. And where does that water go? Into the air inside the freezer, that's where.
Also remember that water is one of the most unique substances in God's creation. Among it's many marvels, water has a characteristic called "tripple pointing." Tripple pointing means that it can exist as a solid, liquid, and gas at the same time in the same place and at the same temperature. Amazing, I know. This happens inside your freezer. It's why your ice cubes slowly shrink.
Bottom line, the inside of your freezer isn't as dry as you think.
Now, as long as you've got me in Dr. Science mode, let me assert something that will be contrary to what you often think: water does not cause rust. Quite to the contrary, in fact. Recently, artifacts were recovered from the wreckage of the Titanic. They are without rust.
Rust is oxidation. Iron bonds with oxygen forming Iron Oxide, the redish brown flakey, powdery substance we call rust. Something like 23% of the air around us is oxygen. So, when iron or iron alloys are exposed to ordinary room air, the iron oxidizes and rust forms. If the object is in water, then the water will keep the air away from the iron.
Ah, but practical experience tells us that knives left in water are significantly more likely to rust. The problem is that most water is not pure. Most water has oxygen dissolved into it. Yes, just as you can dissolve salt or sugar into water, you can dissolve oxygen into it too. This is how fish get the oxygen they need. If you keep a fish tank, you probably have a little pump that bubbles air into the water. Some of the oxygen in that air dissolves into the water as the bubbles rise through the water.
It is this oxygen in the water that rusts metal. Water just brings the oygen into a more intimate contact with the metal and thus accellerates the rust process.
As you go deeper and deeper in the ocean, the oxygen concentration of the water becomes lower and lower. That's why those bits from the Titanic weren't rusted hardly at all.
What's the point (this is a knife discussion, so I have to mention point)? The best place to store your knives would be deep on the floor of the ocean, that's my point!
Ah, but for most of us that is not practical.
The real point of my discussion is your enemy is not water, it's oxygen. If we want to avoid the formation of iron oxide -- rust -- then we either have to get the iron out of our blades or we have to get the oxygen out of our environment.
Sometimes, museums try the later approach by putting precious artifacts like those Titanic pieces into display cases pressurized with nitrogen. This is the "gold standard" for storing artifacts. Unfortunately, it's very expensive.
The other option I offered was to take the iron out of the blades. Unfortuntaely, without getting even more technical then we already are, iron is an important part of what makes a knife take and hold a good edge. An iron-free blade that's strong and yet not to brittle, and that takes and retains a good edge has been the holy grail of knife making since the beginning of time itself. Recently, Talonite and a couple of other new alloys have come darn close.
There is a third option. If we can't take the oygen out of the environment and if we can't take the iron out of the steel, then maybe we can at least keep the two separated. And that's what the time-honored practice of putting thin layer of oil on a blade does. The oil separates the iron in the steel from the oxygen in the air.
There are three problems with oil. Frist, it remains a liquid at most common temperatures and thus it remains runny. Over time, it will yield to gravity and run down off the blade. Second, it's messy and leaves a messy film on the blade. And, third, it does, itself, slowly, oxidize.
Another good option is wax. A thin, transparent layer of wax will harden on the blade and separate the iron from the oxygen. Wax also, slowly, oxidizes, true. But, a good wax will last a long time.
And there is one final option. What we're dealing with here is a chemical reaction: iron reacting with oxygen. Maybe we can add a third chemical that will inhibit this reaction? That's what products like Tuff Cloth try to do. But, experinece has shown that these products and the processes of applying them are not yet perfect.
So, there you have it: the science behind refrigerators and storing blades.
Remember: I have a Master's Degree... In Science and the Sciences.
) but I may be able to add an option not yet metioned. I'm sure the other gun-nuts here know that cosmoline is an all purpose preservative for hardware (military guns are slathered in it for storage, car companies use it for cars going overseas). Basically, if you want a gun to last underground, slather it in wax paper, wrap it tightly in wax paper and put it in a metal container and it will probably outlast you. I'm sure that it will work great for knives.
