Introduction: Shaving Can Safe (that Still Shoots Foam!)

About: Hi, I'm Sam and I like to make things - check out some of my projects below. I worked for this site from 2014 - 2023 and have nothing but love for the Instructables community. Keep making great stuff!

This is something I've wanted to make ever since I saw Jurassic Park way back in 1993.

I mean, who doesn't need a place to hide their ill-gotten dinosaur embryos?

I know I do, that's for sure.

So I finally got around to making my own shaving can safe. And here it is!

On the basic level this isn't really a new idea, as you can buy all sorts of in-plain-sight/diversion safes made from shaving cans, soda cans, and so forth.

But what makes this better and more awesome than a store-bought version (aside from being an easy DIY version), is that this can actually still shoots shaving cream!

Can the store-bought ones do that? I think not.

Let's make one!

Step 1: Stuff You'll Need

You will need a regular can of shaving cream, as well as a travel size can similar to the ones shown.

Barbasol brand worked perfectly for me, and for coolness points it matches the brand that was used in Jurassic Park.

Whatever shaving cream cans you find, just make sure the very top portion of both sizes are essentially the same, and that the caps are interchangeable.

Here are the additional supplies you will need:

  • 2-part epoxy putty (I used JB Weld SteelStik)
  • 1 1/2" PVC coupling
  • Sticky-back craft foam

These are the tools you will need:

  • Standard can opener
  • rotary tool
  • Various attachments for rotary tool (abrasive cut-off discs, grinding bits, drum sander)
  • 1/4" dowel or pencil
  • Band saw, miter saw, hand saw, or teeth (for cutting off a small section from the PVC coupling)
  • Hot glue gun

NOTE: There are several possible ways to accomplish all of the various steps to this project. I made a couple of attempts at this, and I'm going to show you what worked best for me. If you find different approaches that simplify the process, I would love to hear about it in the comments.

Off we go!

Step 2: Empty Can, THEN Remove Bottom

If you are a bad and wasteful person, as I am, empty the large can of shaving cream into the tub and wash it down the drain next time you take a shower.

If you're a good, earth-loving-hippy-type, shave yourself until you run out of shaving cream.

Hippies don't shave, you say? Well then, you're on your own.

Whatever you do, empty the can until there is no more pressurized gas remaining. Do not skip this step!

Once the pressure is relieved, the bottom of the can may be removed with a standard can opener.

Make sure the cutting wheel of the can opener rides right next to the bottom lip of the can as shown in photo 2.

There will still be a tiny bit of pressure remaining, but only enough to spurt you with some foam and not blow your hands off when you initially puncture the can.

I recommend making the initial puncture at the back of the can, as it will make a little wrinkle in the side wall as shown in photo 3. This little ripple will be mostly removed in the next couple of steps, but it's better to hide that at the back of the can just in case.

Rinse out the can, mindful of the very sharp bottom edge. You can lightly sand it with some 220 grit sandpaper to take away the sharp edge; just be careful not to mar the paint.

Step 3: Issue: How Can We Effectively Hide That Bottom Cut?

For this homemade shaving can safe to be any good, it has to function as desired but also pass some serious visual scrutiny.

Successfully hiding that bottom cut is a huge part of the illusion, and doing so was one of the main obstacles I was concerned about overcoming with this project.

Ideally, the lower edge of the can will sit nicely inside the lip of the bottom portion we just removed, without any indication that the two have been separated, or are able to be separated again.

As is, if you set the can back onto the bottom, it appears as shown in photo 2.

Step 4: Solution: Stretch Out the Bottom Edge Just a Hair

The solution is to stretch out the bottom edge of the can just a hair, so it will sit on the bottom portion just inside the lip, and perfectly conceal the cut.

The easiest way I found to do this was to use the smaller travel size can, and gently roll it inside the bottom edge of the larger can.

Hold the larger can flat on a table with one hand, and with the smaller can sitting inside the opening use your other hand to apply a bit of pressure on the smaller can right where the arrow shows in photo 1. Roll the two cans together, working all the way around the bottom of the larger can.

This should be done gently and incrementally, checking the fit of the can against the bottom piece until it fits perfectly, as shown in photo 2.

Step 5: Remove the Top Portion of Can

The top aluminum section of the can is removed by carefully cutting it off with a rotary tool using a thin, abrasive cut-off disc.

You want to be very careful as you do this, so as to not mar the white paint on the domed portion of the top of the can.

Grind/cut into the can just below the silver ring as indicated in photo 1. Work little by little, all the way around, until the ring falls away as in photo 3.

If the center portion stayed in place as it did for me, this can be popped out easily (photo 4).

Step 6: Embiggen the Opening

The opening at the top of the large can needs to just barely fit the top silver portion of the smaller can. We will carefully grind the metal away until the opening is the size needed.

Conveniently, there is a little groove around the top of the can that indicates just the size we need. I marked it with a pencil in photo 1 so it would show up better in the photo, but I found this dark line very helpful when I was grinding away the metal. I suggest marking the groove likewise with a sharp pencil (using a Sharpie or other marker will not be precise enough).

I highly recommend using a thick abrasive grinding disc as shown in photo 3. Work slowly and nibble away the metal right up to the marked groove. Check the fit of the smaller can top as you get close, and continue enlarging the hole until the can top just barely slides though the hole.

Step 7: Adjust Nozzle So Cap Fits Correctly

The cap from the larger can fits the smaller can almost perfectly, and functions just fine.

However, the nozzle (the little tube under the cap) on the smaller can is just a bit longer, so the button on the new cap sticks up and looks kind of funny.

Aside from not looking right, this protruding button will be in the way in a later step, so it needs to be fixed at this point.

Set the nozzle of the smaller can on the edge of a table, and use a blade to nip off about 1/16" from the nozzle tube, as shown in photo 2. (That is a staged photo taken after the smaller can was fastened into the larger one. Disregard the visual inaccuracy and trim the nozzle of the smaller can now.)

Step 8: Issue: How Do You Fasten the Little Can Into the Big One?

The little can may now be inserted through the bottom of the big can, and the top will fit through the open hole.

You'll notice that there is quite a bit of play in the way the little can fits into the opening of the bigger can. Yet we want this little can to fit precisely and look like the original top.

Step 9: Solution: Use the Cap As a Guide and Use Epoxy Putty

The key to getting the smaller can affixed into the larger can in the perfect position is to use the original cap from the larger can as a guide, and to use epoxy putty as the adhesive.

Epoxy putty is great because it can be smooshed and worked into place like clay, and it cures in a matter of minutes with very little mess or hassle.

When the putty is cured, the cap can be removed and the top of the can examined just like a normal can of shaving cream. If you do a good job, it should pass a visual inspection quite well.

The putty only has a couple of minutes of working time though, so you need to move quickly once you knead the two parts together.

This is a tricky step, so I'll try to cover it in as much detail as possible.

First, make sure the inside of the domed part of the can is very clean. Mind your fingers as you wipe it out, as the metal edges will be very sharp.

Cut off a 3/4" chunk of epoxy putty and knead it thoroughly. Roll it into a snake that's about 3 inches long, and press it around the inside of the dome at the top of the can. Press it flatly so there is enough clearance for the top of the small can to pass by the epoxy and out the hole at the top of the larger can.

Insert the small can into the larger can, and pass the top through the hole. The "shoulder" of the small can should engage the putty at this point. Press the cap in place on top of the smaller can.

Turn the cans upside down and balance them on the cap. Make sure the smaller can appears perfectly centered in the larger can.

From the bottom side (which is up now), use a 1/4" dowel to press the epoxy putty firmly down all around the top of the smaller can against the domed portion of the larger can.

In just a few minutes, the epoxy will be cured and the cans locked firmly together.

Step 10: Make Bottom Cap

I tried a few different options for the bottom cap.

Ultimately, the easiest thing was to use a piece of PVC coupling that could be simply press-fit into place (with the help of some craft foam, shown in the next step).

I used my band saw to cut off a 1-inch piece of the coupling. To make this cut safer, I put the coupling onto a piece of pipe. Use whatever appropriate tool you have access to to make this cut.

This piece is centered onto the can bottom with the non-cut edge down (to ensure precision). Squirt copious amounts of hot glue into the center section to hold the PVC in place, and a bit around the outside.

A rotary tool drum sander or other sanding device should be used to put a slight taper on the upper, outside edge of the PVC. This will allow it to slide easily past the craft foam "gasket" that will be made in the next step.

Step 11: Sticky-back Craft Foam . . . Move Over Duct Tape

I love sticky-back craft foam. I keep finding great uses for it everyday.

In this case, it can be used to make a squishy sort of gasket that holds the bottom cap in place.

Cut a few 1/2-inch strips, and layer these on top of each other about 1/4" up from the bottom edge on the inside of the can. Press them firmly in place so the adhesive sticks well.

The bottom cap will fit very snugly, and may actually be somewhat difficult to insert and remove the first few times.

Step 12: Hide Your Stuff

Now hide some stuff in your functioning shaving can safe!

The smaller can does take up some of the space inside, but it's a concession I'm more than okay with.

When the can is shaken, it makes the typical sloshy sounds you'd expect, and it shoots shaving foam just like normal. And that's awesome!

If you want to hide things like jewelry that will jingle and clank around, first wrap the items in a bit of cloth or inside a rolled up ziploc bag. Make sure these bundles fit snugly in the can so they don't bounce around, and you're good to go.

Step 13: Done!

Take a close look at your can safe and pat yourself on the back.

With any luck the only indicator that something might be amiss with the can will be the tooth marks on the bottom from the can opener. But nobody will notice that, except for you! :)

Thanks for looking at this. Let me know if you make one!