about a year ago i bought a 5-gal bucket of drywall mud. I used about 20% of it, and put the lid back on. today i opened it up and the top of the mud is covered with black mold.
anyone know what causes drywall mud to get moldy?
should i skim off the moldy stuff and use what's left, or has there been some chemical breakdown so now this mud will not work properly?
or even worse than that, is this mud "infected" with the same crap that caused the "sick house" recall of the made-in-china drywall?

