Shelf Life
The length of time a drywall primer will be good for can be expressed in a number of different ways and depends largely upon the state that it is in at the time. For instance, the shelf life of drywall primer tells you how long it will be good for, while in the can sitting on the shelf, until it is used. As long as the can remains sealed, drywall primer will generally last for about two to three years while sitting on the shelf.
Drying Time
The length of time that it takes drywall primer to dry will vary by manufacturer. Drying time is important to know because it lets you know the minimum amount of time you can expect your drywall primer to last in its wet state, before hardening and providing the necessary foundation for painting. Drying time can be as little as 30 minutes or as long as about three hours.
Warranty
The amount of time that drywall primers last, after they have been applied, will vary by manufacturer. However, many companies offer a lifetime warranty on the primer. What this generally means is that the homeowner can use the primer and the actual paint for the room to form a permanent bond, resulting in the desired paint job. If the paint job should begin to wear off due to the faulty nature of the primer, the consumer's purchase of the materials would be covered by some type of limited warranty.
Considerations
While it is possible to skimp on costs and try to avoid using an actual drywall primer, the amount of money that this could cost in the long run may not be worth it. Drywall primer is one of those necessary evils that you may want to avoid, but it is necessary so that the paint job will withstand the test of time. Not using a primer can also reduce the effectiveness of the paint and dull the end results of painting.