The Indestructible USB Containment Unit

     Have you ever found yourself behind enemy lines in an alien environment with an important, top-secret message encrypted on a USB drive that could prevent World War III? No? Well, the following guide could assist you if the likely situation ever arises.
     This instructable will teach you how to make a full steel USB container. As the picture shows, it is large enough for it not to be lost yet small enough to fit in a briefcase or jacket. The USB exo-suit  can withstand brutal forces including the following: Drops onto concrete, drops into a body of water, extreme cold, open flame, the weight of a Isuzu Rodeo, hits from a metal bat, an attack by Godzilla (as far as we know), and an extremely violent shot from a nine foot air cannon pressured at 110 psi.

The following supplies are needed in either the construction of the container or to use as a tool in the process of making the container:
1/8 in 1.25x1.25 square steel tubing (length does not matter as much, ours was 6in.)
1/8 in flat steel 
2 lockable steel draw catches (usually come in packs of 2)
3-4 inch thick Floral foam
USB drive
Water sealant tape (sold next to electrical tape at Lowes)
(Optional) USB extension cable (this prevents the need of removing the USB drive from the container)
(Optional) Rust preventing spray paint/coating
(Optional) Lock mechanism
-Tools-
Chop Saw with a steel rated blade
Welder
Small, sturdy, thin object to hollow floral foam (dental pick, small knife, toothpicks)
Metal grinder
(Optional) Rust preventing spray paint/coating

The first step one must perform is to cut the metal. Grab your steel tubing and cut it to an appropriate length to fit the entire USB drive inside, lengthwise. The lack of definite size specifications is due to the varying size of USB drives and if you choose to add an extension cable to it (Mine took up around 4 inches of space within the metal tubing.)
Place your metal piece on the chop saw and cut it at the predetermined marking. Then, grab the flat metal and measure two 1 square inch pieces to serve as caps.
 

Grind all of the burrs and metal “pokeys” off of the metal you just cut. This creates a better fit and makes it look a lot better. Also, metal splinters are not fun, so wear gloves when grinding and cutting.

Locate your floral foam. Make sure you could fit all of your USB drive, with some extra space within it, if it were hollow. Once you confirm that, you can grab your metal tubing you just cut and push it through the foam. Depending on your foam, a hammer may have to be used.
Once the metal goes all the way through the foam, a perfectly sized piece of the floral foam should be stuck within the metal pipe. Push this out. This process can produce a lot of floral foam dust, I would not attempt it indoors.

In this step you just grab your pick like device and scrape away the inside of the floral foam. Just eyeball the proper depth for your specific USB drive. Create the walls of the hollowed area small enough that the flash drive could not move about on the inside. Make sure you do not go all the way through and do not let the sides break off.
Once complete, the majority of the flash drive should not be visible from the side when it is concealed in the foam.
The reason the USB needs to be concealed in the foam is so that there is no space for it to bump around inside. Also, the foam serves as an excellent insulator against heat and cold.
Remove the foam and flash drive now that is all sized and hollowed.

Now, set up your welder (mine was a mig, others should work though). Take one of the metal squares and weld it to what would be the bottom of the case. Make sure it is level before you weld it so you can have it sit upright.
Now, once the square is sitting on the bottom of the case, weld it on all four sides. Make sure no gap exists as it would allow water to leak in. Optional: grind the welds down in order to improve aesthetics. Just make sure you do not grind through the metal.

Place a clamp on the side of the container and the clamp hook on the nonwelded metal square, which acts as a lid. Align them on the side of the container and mark their positions so they can easily be put back in the same place. Do this for both sides.
Being very precise, weld a clamp hook on each side of the lid square. Be sure to not make the weld too big because it could either distort the clamp hook or make it so the lid won’t rest evenly on the lip of the container.
Then, place the clamp on the sides of the container on the markings you drew earlier.  Weld it on but make sure the welds will not interfere with the clamping system. I ended up welding it on the bottom of the clamps, in and around the screw hole. This way the welds would be sturdy but would not affect the effectiveness of the clamp.
Once cooled, the clamps should close and lock the lid to the container. It should be secure but not tight.
The reason I used draw catches is so that the container could be locked, further adding protection.

This is rather self-explanatory. Insert the foam encased USB drive and the optional extension cord into the container. Note: if you choose to have an extension cord, make sure that it is plugged in to the USB drive when you insert it.

Cut small strips of the electrical sealant tape and apply it to the lips of the container. The corners can overlap so extremely precise cutting is not necessary. (Optional): You could add a second layer of water proofing by adding it to the lid, we did not find this necessary. (It may be wanted if you plan on taking this to extreme depths though.)
Now that the sealing is applied, clamp the lid back onto the container. You do not need to wait for the seal to set. When clamping, you will notice a stronger tension on the clamps.
After letting the container sit for a few minutes, you should notice that it is very hard to get the lid off the first time. This is normal. 

This is the final, easy step. Just paint your container if you want to. Once completed, you can now go about tossing your important information off tall buildings.

(Optional) The clamps have the option for a lock, you can either add a bike lock, gun lock, two padlocks, retina scanner, or any other lock you see fit.

But how much can it really take?