Painting on canvas and primer?

Did my acrylic gesso primer go bad?

• I just got done applying the first coat of my Phoenix gesso acrylic primer onto an old wooden door that i was gonna use for an oil painting. I have had this gesso now for aroynd a year or so and when I opened it this time, there was slight yellowish dust looking stuff in it, not alot, but enough to where it was noticable and the primer was a little hard to stir at first. So, I just stirred it up thinking it was all fine and that there was no problem. The gesso eventually was back to it fluid and white state and ready to apply to the door. The gesso spread fine on the door and dried fine but jesus christ it smelled AWFUL and STILL does. I have used gesso and other primers many times both on wood and on canvas and this is the first time this has ever happened. I always keep a strong lid on the gesso so nothing can get in...but it stinks like hell... My guess is that it was mold now just by the way it smells...the smell is unbearable, not like the normal primer stench, more rotten kinda smelling. But like I said, it didnt smell when i first opened it, it was fine once I stirred it, it applied and dried just fine but now the stench has become unbearable and it just smells rotten. What should I do? Should I just ditch the door and get new wood/ gesso? Why do you think this happened? Help please...

• Answer:

  The gesso didn't go bad. What happens with any large container of paint (and gesso is a form of paint) that sits over a long period of time is that the bonding resin separates from the pigments and rises to the top. So, no, you don't have to throw it away. All you need to do is get a stirring stick and stir the gesso really well, making sure you stir it thoroughly so that resin and pigment become one again.