This is a rather involved instructable; however, the reward is well worth spending the hours (and i can guarantee you will spend less time on it than i did -- i had MANY problems which i will explain how to bypass). I like dualism and this project is perfect for me because the final product serves as both a normal can of Dust Off and a place to store some small valuable items.
The first step is to obtain an empty can of dust off (or another empty can of compressed air). Obviously if a can is empty you may not have one laying around, so i CAREFULLY
emptied an existing can which was low on gas. Follow the set of "DO NOT's" on the back and carefully use spray it until there is nothing left. Now comes the fun part.
Step 1: Gather Materials
Pictured are the basic materials which you will need to create the Working Can Safe. This picture was taken before i started the project; i later learned that the Gorilla Glue will not work, so do not use the Gorilla Glus in the later steps. In searching for a bottle, i found that a "Move Free" vitamin bottle is a perfect fit. Whichever bottle you decide to use, make sure that it fits (step #3) and that the cap is a normal screw off, NOT A CHILD SAFETY ONE!.
Step 2: Cut the Bottom Off the Can
This part requires some patience to make a clean and even slice all the way around the can. To to it you are going to have to turn the can opener on its side so that the blade is cutting the side of the can, not the concave bottom. I could not get a picture of this part as i was by myself and could not hold the camera in the right position (believe me, i tried). Once the concave bottom is free, you are going to need to file down both the flat edge of the can and the edge of the bottom to make them smooth and fit together perfectly. The bottom is going to need to rotate inside of the bottom, so make sure it is smooth al the way around to look inconspicuous to bystanders.
Step 3: Prepping the "Safe" Part
After the bottom of the can has been removed, test fit the vitamin bottle to see if it is a close fit. It is better that the bottle is a little snug. DO NOT FORCE THE BOTTLE INTO THE CAN, ONLY TEST TO SEE IF IT FITS!!!!.
If the bottle does fit, begin removing the label by rinsing under hot water, then using a razor blade to CAREFULLY take off the label. Do not put force behind the blade, merely use gentle force to remove the loose label, working away from your fingers at all times.
After most of label has been removed, apply some Goo-Off to a paper towel and remove all of the glue and remaining label. You may have to go over the entire bottle three or four times to remove all of the tackiness.
Once the tackinees is all gone, use a fine to medium grid sandpaper to lighly sand off a thin layer of plastic so the bottle fits better. I found the when you can drop the bottle into the can and its takes about a half second to fall to the bottom that its a good fit (it takes this long because the air is forced to travel around the falling bottle. Since it is a good fit, it takes the air a second to get out of the way of the bottle. There needs to be some room around the vitamin bottle for the glue to fit, but not so much of a space that the glue becomes a structural component. Test fitting is crucial here.
Step 4: Attaching the Safe-Door
I started this step with the old cap because i thought i would be saving myself a step -- it already had a hole in the center so i figured i didnt have to drill it...only the hole wasn't actually centered, just kinda there. I found the center of the concave can bottom with a center finder (not sure of the exact name; however, this is what my dad calls it) and marked it with a permanent marker. Next i found the center of the new cap and used a drill press and unibit to drill a fairly large hole through the center of the cap. As the can bottom is concave and the cap is flat, if glued as is, there will be very little contact and thus very little sheer strength. To compensate, drill a large hole in the center and when glue is applied around the circumference of the hole, there will be MUCH greater surface area thusly increasing the sheer strength of the bond. Using the JB Kwik weld, attach the caps together. Prior to the glue's setting, spin the cap to ensure that the bottle cap is centered -- this is done by correcting any wobbles.
Step 5: The Safe
This next step was quite unfortunate for me as i spend hours trying to figure it out only for it to have failed miserably later...this is why i am going to let you know how to NOT make my mistake.
Because this can is intended on working as both a safe and a temporary can of Dust Off, i needed to think of a way to pressurize it. Sure an aircompressor would have been a) readily available, b)simple, and c) smart; however, i opted for the "cooler" idea of using dry ice to build the necessary pressure. The dry ice in conjuncture with the Gorilla Glue turned out to cause even more hours of work to fix the problem i created for myself. I will include all of my pics on the dry ice stage in the end of this instructable incase any daring souls out there would like to attempt to critique my idea and see if they can make it work....for the rest of you, i suggest just using an air compressor (or even a bike pump)
To attach the vitamin bottle to the inside of the can, mix up some JB weld and apply liberally to both the inside of the can (away from the opening) and along the bottom of the bottle. Other epoxies or waterproof glues may be used and are encouraged as this seam will need to endure air pressure. Once the bottle is in place, give it a little twist to smear the glue all around (remove the cap first or it will snap off. then reattach the lid so that the bottle sets in the correct place.
Step 6: Your Finished
Now you are finished the project. The video of it working, if you havent already seen it, is in the intro. Now you may put your most valuable items inside of the safe for safe keeping. Suggestions are rings and other jewelery, notes, private ideas/designs, money, SD cards, and anything else that you dont want in the open. For the willing, the next step is showing my mistakes, like i said, if you are willing to try and figure it out, please do. I hope you enjoy your secred hiding place now....oh yeah, i wouldn't necessarily suggest leaving the can pressurized all the time as it may leak or eventually wear out the glue seal. my suggestion would be to use an air compressor set to about 15 PSI and carefully pressurize it by depressing the trigger of the can and allowing the air compressor nozzle to fill the can's chamber with air. Although you may not be able to dust your computer, if a curious bystander picks up your valuables without knowing, the can will work as a temporary dust off so that he does not become suspicious.
Step 7: Dry Ice Out-takes
Originally i wanted to pressurize the safe with dry ice. I used all the necessary safety precautions: gloves, protective glasses, put my dog inside and used the dry ice in a well ventilated area...i even had my Physics teacher go over the Ideal Gas Law with me to deterine just how much dry ice i would need to obtain a safe PSI after sublimation. The gorilla glue's problem was that when i added the dry ice, even though i depressed the trigger to alleviate pressure buildup, the CO2 still pushed around the expanding glue.