Office of Steam Forum for Model & Toy Steam Gas & Hot Air Engines

I did some research and spray paint does expire.  Best that I can tell Krylon has 5 years and there is a date code under the cans, though they don't make it so easy to read.  Luckily someone asked years ago on the Krylon side and a staff member decoded stamped number on the bottom.

"To determine how old a particular can is, the batch number should be stamped on the bottom of our aerosol cans/containers. It will start with 1 or 2 letters, followed by 4 numbers. There are additional letters and numbers, but they have no bearing on the shelf-life. In fact, specifically, only the 4 digits matter; in terms of how old our product is.

Example:

EM2352

We manufacture by the Julian calendar.

The letters at the beginning of our code are the plant code and have no bearing on the manufacture date.
The 4 digits is all that is relevant to determine how old that particular can and contents are.
The first 3 digits are the day of the year our can was manufactured on.
The 4th number is the year of manufacture (always a 1 digit number).

So for this particular can, the batch date is the 235th day of 2012, or August 22nd, 2012."

• The can I pulled from my garage trash can has a code of: "HL2249CB" = 229 day of 2019 or August 17th of 2019.  At least a year left before "official" expiration date.
• The can that is discolored and not curing right: "HL0764EP" = 229 day of 2014 or March 17th of 2014.  Over 4 years past its "official" expiration date.

That is way more than I really wanted to know about the weird stampings on the bottom of a spray can.  I hope I can get a can or two that is under 5 years old!  Ugh!