Thread by @mattbramanti

let's talk about these little guys

🧵

this is a can

sometimes known as a tin can, or in the Commonwealth as just a tin

despite the name, they're not made primarily of tin and never were

they used to be made of tinplate - a thin sheet of steel with a thin coating of tin

this prevents corrosion

nowadays they're usually made of steel lined inside (and sometimes outside) with a plastic film

this started a lot earlier than I thought - the 1950s

they used epoxy resins made with bisphenol A or "BPA"

this has become a problem

the problem is BPA is an endocrine disruptor

it can block some hormones and mimic others

it's been linked to heart disease, fertility problems and liver failure

and the body isn't great at eliminating it, so it builds up over time

BPA can leach into food from the plastic lining

this leaching happens faster when the can is hot or when the food contains high levels of fat or acid

the Can Manufacturers Institute says 98 of U.S. cans are now BPA free

manufacturers now use polyester epoxy, acrylic or olefin polymers

back to the can itself

for purposes of the next few tweets, I'm gonna talk about probably the most famous can there is

this can is what's called a "picnic" or "No. 1" size

obviously there are a bunch of sizes, but we'll get to that in a little while

it has a capacity of 10.94 fluid ounces, but Campbell's fills it to 10.75

it stands 4 inches high and has a diameter of 2 11/16 inches

wife is running late and I gotta put a couple kids to bed

please enjoy this brief musical interlude

sorry about that

back to the can

including lid and label, it weighs 46 grams or 1.6 ounces

I said this was probably the most famous can there is

in 1962, pop artist Andy Warhol painted a set of 32 canvases

one for each flavor Campbell's made

Warhol said he ate a bowl of Campbell's soup for lunch every day

Irving Blum, Warhol's gallerist, sold five of the paintings

Dennis Hopper bought tomato

Blum soon regretted this, and bought them back to keep the set together

in 1996, Blum sold the set to the Museum of Modern Art for $15 million

let's get back to the actual cana

let's get back to the actual can and talk manufacturing

a soup can is what's called a "3-piece can"

a body and two ends

it has three seams - one each at the top and bottom, and a third down the length of the can

like we always do, we'll talk about each part in turn

actually we won't

I numbered those stupidly

3. the body

this starts out as a huge coil of steel strip

it's cut into large sheets, big enough for several cans

it's then coated on what will be the inside with epoxy and baked in an oven, then cut into single-can sizes

a machine rolls it into a cylinder and welds the seam - applies an electric current to the edges, heating the edges enough so they melt together

another coat of epoxy is sprayed along the inside surface of the weld and hot air is blown in to cure it

the cans now move to a flanging machine that bends the top and bottom edges outward, so they can mate with the ends

6 & 7. the maker's end and seam

this is the bottom of the can

so for purposes of these illustrations, the can is upside down

a lid with a curled edge is placed over the flanged end of the can

a machine pushes on the curve of the lid so that it rolls under the flange of the can body

a second roller than mushes the whole seam together

this was the most surprising part of the process to me - no weld, no solder, no glue or anything

just metal and metal and force

🤘

4. the beading

these are the ridges or corrugation running latitudinally around the body of the can

they strengthen the can to prevent dents or crushing

the empty, one-ended can is run through a machine that applies rollers inside and out to create the beading

1 and 2. the canner's end and seam

this is the top of the can

the can is filled with its contents - hot

hot enough to sterilize the food and the inside of the can

then the top end is crimped on

as the can cools, the small amount of air in the headspace contracts and creates a partial vacuum

dangit, i broke the thread

i hate when that happens

continue here

after the can is filled and sealed, it goes into a machine that glues the paper label to the can

apocryphal story time

Carnation Milk first appeared in 1899, and at first struggled to find a market

the company put out ads asking customers to write in and suggest a slogan

the winning entry:

Carnation Milk is best of all
No tits to pull, no hay to haul
No buckets to wash, no shit to pitch
Just poke a hole in the son of a bitch

I know what you're thinking

"but how? how can i possibly break into this impregnable steel beast?"

which brings us to can openers

these are can openers

by various means, they puncture the can, allowing access to the tasty contents

we'll talk about each kind in turn

this kind first

the shitty Census Bureau doesn't collect this data, but I'd guess this is the most common kind of can opener in the American domestic setting

it features two engaged gears

each gear is topped with a wheel

the bottom wheel is is knurled to engage with the bottom surface of the can's top flance

the top wheel is sharp

when you clamp the device onto the can, the sharp wheel punctures the lid just inside the flange

as you turn the handle, the can rotates and the wheel cuts through the top of the lid

this kind does pretty much the same thing, but with an electric motor

does anyone have these anymore?

when I was a kid we had one attached to the bottom of the kitchen cabinets

seems dumb now

anyway, here's how they work

there's still a ridged bottom wheel, as you can see below

and there's a blade

there's also a magnet to hold the lid

you stick the can in there so the flange is between the bottom wheel and the blade, with the magnet stuck to the lid

push down the handle, and an electric motor turns the can, allowing the blade to slice through the lid

when it's done, you remove the can and the lid is cleanly held out the way by the magnet

space age stuff

on to this little guy

the simplest form of can opener

the church key

this is used to open cans of liquid like this

because it doesn't take the lid off

it just pokes a hole in the son of a bitch

the pointy end goes on the top of the top of the can such that the protruding bit engages the flange

pull up and you have a nice triangular hole

do the same thing on the opposite side and voila

pour yourself a glass of delicious V8/Carnation/Pennzoil

then there's this one

the P-38 can opener

its bigger brother is the P-51

it was created in 1942 by the U.S. Army Subsistence Research Laboratory along with the canned K-ration

it's just two little pieces of steel hinged together

you stick the flange of the can in that little notch

press down to puncture the can, and wiggle the P-38 back and forth to walk it around the top of the can

I have not been able to find out definitively the origin of the designation P-38

it happens to share that designation with the Lockheed P-38 Lightning, a high-speed fighter that debuted the year before the P-38 can opener

is it an ironic reference, because the P-38 Lightning is fast and cool, and the P-38 can opener is slow and a pain in the ass?

or is it the length?

the P-38 is just over 38 mm long and its big brother the P-51 is about 51mm

the Army says it took 38 wiggles to open a C-ration can

army.mil/article/25736/…

so I'm not sure how it got its name, but I lean towards an ironic reference to the fighter plane

its official Army designation was "Opener, Hand, Can, Folding, Type 1"

regardless, it's a pretty clever little piece of kit

Samuel Bloomfield got U.S. Patent 2,412,946 for it

patents.google.com/patent/US24129…

note the ridge stamped down the center

this strengthens the handle

just like beading strengthens cans!

note the hole punched in the corner

perfect for wearing on a dog tag chain

other than a screwdriver or prybar (and the P-38 can do both jobs) it's just about the most basic mechanical device imaginable

the J.W. Speaker Corporation of Milwaukee made 50 million of them during World War II

they say necessity is the mother of invention

this is especially true of military necessity

that's where canning came from

in 1795, Napoleon's government established a prize of 12,000 francs to encourage the development of long-term food preservation, so the Grande Armée could march on its stomach

it took 14 years, but the prize was awarded to Nicolas Appert

Appert figured out that food cooked in sealed jars didn't spoil

he didn't know why, of course - the germ theory of disease was not understood and Louis Pasteur wouldn't even be born for another decade

but if it works, it works

Appert was an interesting guy

he was a revolutionary and was present at the execution of King Louis XVI before getting caught up in the Reign of Terror

he sold bottled fruits and veggies for years before winning the prize

he went bankrupt in 1806, and the 12,000 franc prize in 1810 didn't help him all that much

the same year, a British inventor figured out how to preserve food in tinplate cans, which were lighter and tougher

in 1828, Appert asked to be awarded the Légion d'honneur

Louis Phillipe I turned him down, and Appert died penniless in 1841

ever thus to commies

so that's cans and can openers

if I missed anything or got anything wrong, let me know

previous deep-dive threads are here:

98 percent*

I regret the error