How long does bullseye shellac last?

[Mason Schultz]

Ive been seeing mixed answers online, anywhere between 1 to 3 years before it's unusable. I have the code provided with my can, I'm just curious as to how long it will hold up.

Simultaneously, what happens if you use shellac that is expired? Thanks!

[Kris Cook]

I have done a fair bit of research as well and I think you are safe within a year. Having said that, if there is any doubt I would do a test strip. I am sure there are instances where the canned stuff will go longer than a year and I would say if it drys hard on a test strip you should be good to use it no matter how old.

[glenn bradley]

Test to be sure of course but, I have used seal coat that has been in a glass container for over three years without issue. I believe the advertised shelf life is two or three years can’t recall which for sure. Zinsser’s site will tell you.

Ah, here we are . . .

Seal Coat Label.JPG

And a reminder on how to read the cryptic can code:

Here is how to read the stamp.

• The first letter “S” identifies the plant that packaged the product. In the case of the two cans shown, it was Somerset, NJ.
• The first number is the last digit in the year the shellac was packaged.
• The second number is the month. For October, November and December the first letter is used instead of a number: “O,” “N,” or “D.”
• The third and forth numbers provide the date within that month.
• The fifth number or letter indicates the “run” on that date.

[Edward Dyas]

Ive been seeing mixed answers online, anywhere between 1 to 3 years before it's unusable. I have the code provided with my can, I'm just curious as to how long it will hold up.

Simultaneously, what happens if you use shellac that is expired? Thanks!

The shelf life would largely depend on the conditions where it is stored. Basically the cooler it's kept the better. You also can't really go by an expiration date. The date gives you idea of when to be cautious of the finish but you should be able to tell when it's actually gone bad. When you stir it if it seems to have lumps in it where you think you are going to have to strain it, the finish is bad and should be disposed of.

I have a refrigerator in my shop and finishes I don't use real often I keep in the fridge. The cold will extend the shelf life. Just take the finish out a day or so before you plan to use it.

[Frederick Skelly]

Agree with all the above answers. In my shop, I find that Zinser Seal Coat shellac goes bad about 18-24 mos from date of manufacture. But mine is stored on a shelf, not in a fridge. After about 18 mos, I do a test strip before using. YMMV.
Fred

[Bruce Page]

I don’t have a direct answer to shelf life but I recently had to clean up a sticky mess after the bottom seam of the 1 quart can split. The can was ~ 3 years old and the split happened some time ago.

[Curt Harms]

Agree with all the above answers. In my shop, I find that Zinser Seal Coat shellac goes bad about 18-24 mos from date of manufacture. But mine is stored on a shelf, not in a fridge. After about 18 mos, I do a test strip before using. YMMV.
Fred

I think a test piece is good policy for most glues and finishes. I did have a seam bottom leak on a can of Bullseye Shellac but it was a pretty easy cleanup with DNA.