Calling all scientists - a Coke question

I have saved cans of Coke with the Christmas design each year & kept them on a top shelf in my kitchen. Not sure why, except my two sons can put them in the yard sale when their ole parents are dead & gone.

Anyway, opened the cabinet last night, & Coke was seeping down the inside of my cabinet. We finally found the can that it was coming from. A tiny hole had developed near the top of the can. Nothing had punctured it, nothing had changed as far as the temperature of my house, no recent shaking of the can, etc. It just got a hole in it. Fermentation??

What's your theory. The culprit had sat there from 1986, the date on the can.

My guess would be corrosion. Here are 3 articles about it:

“Luckily most pop cans these days are made from aluminum, which in not corroded by the pop inside (in most cases, anyway. If a crack is started when the can freezes and expands, for example, the acid can concentrate in that tiny crack and begin a hole.)..........”“When pop used to come in steel cans, the inside was coated with tin, a very expensive metal by comparison, to protect it from corrosion, and also to avoid that "metallic taste".” http://www.madsci.org/posts/archives/mar2000/952901578.Ch.r.html

“Did you know that soda cans have a thin, plastic liner inside to keep the acid in the soda from reacting with the metal?..........” http://www.stevespanglerscience.com/experiment/00000100

“..........The can’s edge gets trimmed, the design gets printed, and a varnish is used as protection. Cans are baked to dry the paint, and a synthetic coating is sprayed inside them. A second baking is done to "cure" the coating.” http://www.consciouschoice.com/2000/cc1301/popfizzgulp1301.html

Generally, the 6 oz glass bottles are valued higher than the cans. SO, if you keep collecting, you may wish to switch to collecting glass bottles.
When collecting cans, you really need to watch the temperature in the can'e enviroment. Often, when stored high up in your cupboards, cans can get too hot in the summer which affects seam at the top of the can. The expansion and shrinkage will sever the seal and then the sodas acid will do the rest.

Many can collectors emply the can. Unlike glass bottles, which lose most of their value when it's been open, open coke alumnimum cans in the collecting world are really no less valuable than the properly emptied ones. Notw I'm not talking about opening the can from the top, which will cut the value, and a cracked seal will cut the value too. Generally, collectors make a pin hole in the center of the can on the bottom to let the contents out. Clearly, it's tougher to store emptied cans because they are more fragile and dents will really lower the can's value.

You might want to talk to your local collectibles seller and ask if knows anyone who can show you how to properly empty collectible coke cans.

quote:

Originally posted by lostnthemail

I have saved cans of Coke with the Christmas design each year & kept them on a top shelf in my kitchen. Not sure why, except my two sons can put them in the yard sale when their ole parents are dead & gone.

Anyway, opened the cabinet last night, & Coke was seeping down the inside of my cabinet. We finally found the can that it was coming from. A tiny hole had developed near the top of the can. Nothing had punctured it, nothing had changed as far as the temperature of my house, no recent shaking of the can, etc. It just got a hole in it. Fermentation??

What's your theory. The culprit had sat there from 1986, the date on the can.

I'm sorry that happened. I guess I'd better check my Harley Beer collection.

quote:

Originally posted by Scorereader

Generally, the 6 oz glass bottles are valued higher than the cans. SO, if you keep collecting, you may wish to switch to collecting glass bottles.

I've been buying those for a friend for several years. She's got quite a collection.

I have aPEPSI 6 Pack and one extra can (for demonstration purposes) that are in the "Subliminal-Sex" graphics done in 1990-91. None have been opened, but at least 85% of the contents have 'evaporated' over the years. No leaks noticed on any of the cans...the contents have just 'disappeared'. For those who may have missed these cans when they were on the shelves, the instructions were to stack them so that the 'neon graphic' would spell "SEX" vertically on the cans...to deliver the subliminal message of 'satisfaction' involving PEPSI. They were on the Selves in SoCal for less than a year.