 What is the working time of art resin? The working time, also known as the pot life or the open time, is about 45 minutes. This is the period of time that you have to work with the product before the curing process really sets in and the art resin becomes too stiff to manipulate. So the working time can be affected by heat. If you've put the product in a warm water bath prior to mixing it, or if you're just working in a warm environment in general, that working time or open time is going to be decreased as well as the cure time.