I picked up three 5-gal buckets of premixed joint compound two years ago on sale, then my refurb project got put on hold. Never opened until yesterday, there is no bad smell to the compound. More like just a slight paint/putty smell. The mud is light greyish in color. I know mud has a shelf life, and I don't want to use stuff that really isn't good. I haven't yet tried mixing this up to check consistency, but if consistency is good, no smell, no mold, etc. is the mud really not usable being this old? I hate to throw money away, but I also don't want to spend time and effort using the stuff if it is somehow compromised.

I have seen other forums talking about mold, smelly compound, etc. in partially used containers. That, I totally understand, would indicate that one wouldn't want to use the stuff. But I have only seen one suggestion that the holding power of the compound suffers with age. Is this true?

Along the same lines, does even the powdered stuff go bad? I already used some setting compound, about the same age, to do my tape embedding. Seemed to be ok, but I'm new to this. Want to find out for sure before having to redo all my work! :-)

 

The buckets of j/c should be ok provided they haven't been exposed to freezing temps and it mixes up well. I've never had any setting compound go bad unless it go wet.

 

Might consider just taking some and mashing it on a piece of scrap board/drywall or something. Let it dry, take some sand paper to it and see what happens. If it sands properly/per usual, doesn't pop off in chunks it's probably fine.

My understanding is that if it's gone bad..... You'll know when you take the lid off. Right away.

 

The concern I would have would be the drying out of the compound. This is experienced on partial buckets held between jobs. Any compound that gets on the top or the sides that is not part of the greater mass of the bucket can skim and dry out. They fall into the good mud and play havoc when you try to use it on the wall. The fine pieces of dried material causes streaks and pull marks making it near impossible to pull a smooth joint. If this is the case, you will know straight up when you begin work and give up on the old and get a new batch.