I have a bag of powdered thinset mortar from Home Depot. I am wondering what the actual working time is on the mix once you have it mixed with water?? The point at which it is too stiff to realistically work anymore.
I would venture to say 30-45 minutes. I'm certain it would depened on temperature, humidity and how much water you mixed in. I can say that if you mix it in a plastic container that it will set up quicker than if you used a metal container.
That information is included on the bag, or should be. It is on every bag of thinset I have bought from HD.
Could get an hour and a half or so, depending. And stir it occasionally by hand with a margin trowel.
According to their literature:
"Material in bucket will remain workable in excess of two hours."