Shelf Life and Storage : Monstaliner

When stored at room temp or colder (no hot garages), unopened ML will be good for at least 1 year.

No hot garages, gallons upside down

How to determine if old Monstaliner is still usable:

Checking Old liner if still usable (shelf life of unused Monstaliner)
Turn the gallon cans upside down and knock hard on the bottoms.
If it feels solid like settled cement it will be hard to remix and re-incorporate all the pigment so as not to have lumps.
If you want to open the gallon can to check after initial inspection, do so and jam the wooden paint mixing stick to the bottom of the can to see what it’s like.
If the stick goes right through the sediment and touches bottom with just a little effort you can definitely mix and use it.
If the stick stops and won’t go to the bottom there’s a slim chance it’s usable.
Keep in mind that old cans of bedliner may have the lids glued on and be hard to open. You may wind up mangling the edges of the cover while trying to open them. At that point you would have to use the material or lose it if you can’t reclose the can unless you are ready to do your project now.

Tintable ML is probably still good after 2 years BUT, the lids may be glued on the gallon cans.
Shake a gallon vigorously to make sure it’s still liquid. Try carefully to pry up a lid with a wide flat head screw driver.
If the lid does not give in one spot, turn the can and try other spots. Worst case you will mangle the lit to get it open eventually in which case you will need to use it or lose it or repack the contents into a new can
Catalyst will still be fine even if there is some ooze around the lids.
Tints will still be good but may be settled badly depending on what colors they are.
Shake very well and check for sediment, scrape off the bottom with a screw driver and re-shake well until blended with no lumps

No issues, shake the tint VERY well
Lid on gallon of liner may be stick a little
Catalyst is fine even if there is some ooze around the lip