How long does joint compound last

[Eigenvector]

I got one of those boxes of joint compound, dumped it into a Homer bucket and have been using it to do the mudding on my ever present drywall jobs. I use a layer of water on top of it to keep it fresh, plus I also keep a plastic cover over it to keep the buggies out and the cat hair out of it.

How long does it last if kept this way? I noticed once that a couple of patches of green mold formed on the margins where the water wasn't totally covering it. I wiped it away and recovered it and haven't seen any return.

Should I toss it at this point, its about 2 months old, still handles like joint compound and appears to do a perfectly fine job. Waste not want ot - ehh?

[Jimi]

As long as you keep a layer of water over it, It will last probably over a year or so.......the green mould like substance was the water evaporation residue from sitting without using.. If you dumped the film of water every month or so and restirred the mud compound, then added the water as a sealeant over top.....then you could make it last probably last indefinately. Jim

[Eigenvector]

That's good to know, although I sincerely hope that I don't have to keep it for longer than another year. I'd hate to think I have to do THAT much drywalling.

[deke]

I have some that is about 5 years old and going strong. The only objectional part is the smell. And adding a little water to make it less stiff.

[EXT]

For longer term storage, I have smoothed out the top and then added a thin layer of Javex. Kept the mould and smell away --- that is if you can stand the smell of Javex, when you use the compound, it pour it off, don't stir it in.