Kilz is the brand name of a paint primer used by many homeowners. It is a deodorizer as well as a stain-blocker and sealer. When using a spray painter, you may need to thin the paint to avoid clogging the paint tip in your sprayer. There are many different types of Kilz and you should always check the manufacturer's directions on the can for the specific type of Kilz you are using in case they deviate from the standard thinning of Kilz primers.
Remove approximately 1 1/2 cups of Kilz from the gallon. If working with a larger container of paint, adjust accordingly--approximately 10 percent of the paint.
Replace the amount of paint you removed with water.
Stir until completely mixed together and you cannot see a separation of paint and water.
Add the reserved paint back to the can when the can is about half full, along with another 1 oz. water for each 1 1/2 cups of paint. Or add directly into the sprayer tank if room allows.
You should only thin Kilz if using a sprayer; it is unnecessary when using a roller or brushing.