How many cans?

Disclaimer: The experiment isn’t being conducted by me, but I have taken an interest in it because it involves:

Naturally, once the experimenters got me thinking about this, I had to estimate the answer. They’re not done yet, so if you see them, ixnay on the answeray.

To begin with, they’re examining cans of Gillette Foamy with Aloe & Allantoin. I’m not incredibly picky with shaving cream. This stuff is probably the same formula marketed in a myriad of different ways. Except this shaving cream is compatible with the Trans-Warp 10 razor. (Next up: a Razor That Goes to Eleven for those special occasions when you need an extra-close shave.)



Ahem.

A can actually weighs 14.8 ounces, of which there are guaranteed 11.0 ounces of “product.”

That’s all fine and dandy, but what we need to know is the volume. One question that lingered was how much the aeration affects the expansion. To calculate this, cans were frozen. The bottoms were hacksawed off and the contents dumped into a bucket where it could expand.

Based on Rob’s earlier work, and my personal consumption of this product, I wasn’t expecting a whole heck of a lot in each can. The expanding frozen cream (top bucket) grew to only 3″ tall. This was kind of disappointing, really. In contrast, the room temperature can squirted into the bucket yielded 5″ worth of hot shaving action. Conclusion: the aeration fluffs it up considerably. If we were playing an actual prank, it would also make this a lot easier than freezing and cutting the bottoms off cans.

The largest tub expanded to about 5″ from the bottom. The container is 9.5″ in diameter. This gives us an estimated volume of: (9.5″/2)2 * pi * 5″ == 354 cubic inches of shaving cream 354 cubic inches / 1728 cubic inches per cubic foot = 0.20 cubic feet of shaving cream

Because I want to know, I measured the original can. It’s 2.5″ in diameter, 4 3/8″ in height. There’s a lens-shape at the bottom, but I estimate this “cutout” volume is less than the spout above the rim. I can also hear the shaving cream sloshing around, so let’s just simplify this and compute the volume of the cylinder: (2.5″/2)2 * pi * 4.375 == 21 cubic inches 21 cubic inches / 1728 cubic inches per cubic foot = 0.012 cubic feet

So, based on this, the shaving cream expands just over 16 times its unaerated volume.

Finding the volume of the car proved to be tricky. The owner’s manual provided a “cargo capacity,” which I assumed meant with the rear seat down. I measured the volume of just the cargo area with the seat up, subtracted this from the bigger number, and came up with an estimate for the rear passenger compartment size. To confirm the calculations, I measured the rear compartment volume legroom plus the torso. That number was within 5% of the derived value, suggesting I could use the published front passenger numbers to compute the volume there. I came up with the following Front passenger area: 52 cubic feet Rear passenger area: 37 cubic feet — see, you knew it was always cramped back there. Cargo area (in this case, referring to what’s available behind the rear seat): 27 cubic feet Total interior room is approximately 116 cubic feet

The Bottom Line

It would be an awesome, minty-fresh, very expensive April Fools’prank. I estimate that it would take:

116 cubic feet / 0.20 cubic feet of shaving cream per can =

580 cans of shaving cream

This is nearly four times the amount of shaving cream I’ve consumed since I was twelve. And as for cost, at $2.09 per can, even with free shipping (535 pounds!), the experimenters would be out about $1,200.


A more interesting variant would be to use biodegradable shipping peanuts, at $700, delivered anywhere in the continental U.S. (And no, they don’t pack peanuts in peanuts. I asked.)