What Is the Difference Between Latex & Water-Based Primers?

Water-based primers are the most convenient to use. Generally, water-based primers are the least expensive option, and they are also the easiest to paint with. Compared to oil- and shellac-based primers, water-based primers create less of an odor, and they dry faster. Since the base is water-soluble, the primer or paint is easy to clean up with water and soap.

Oil-based primers require a special brush to apply and are more difficult to apply evenly to a surface compared with water-based primers. They also take longer to dry and produce a stronger odor. However, oil-based primers bond more strongly to surfaces and therefore last longer. Since oil is insoluble in water, soap and water often can't be used to clean stains off oil-based primer surfaces. However, since oil-based primers are tougher, you can scrub them much harder, allowing you to clean off tough stains such as ink without marring the finish.

Shellac-based primers use a type of resin as a base, which makes the primer very thick and tough once it's dry. For this reason, shellac-based primers are best suited for outdoor surfaces such as decks and picnic tables, as the resin base will allow the primer to withstand the elements. Shellac-based primers adhere well to slick surfaces such as smooth wood, metal and glass.

Consider the surface you are painting to decide which type of primer and paint to use. For large interior surfaces such as walls and ceilings, a water-based primer is most convenient. However, if you plan to paint over the primer, choose an oil-based primer, as it will have a stronger bond with the (oil-based) paint you apply. Oil-based primers are better suited for surfaces that experience contact and abuse, such as woodworking and cabinets, as water-based primers are more inclined to chip off these surfaces. Shellac-based primers are best for use on outdoor surfaces or indoor surfaces that require maximum protection or sealant.