All latex paint is a water-based paint. Vey often it must be thinned due to paint dry out in the can or because of very warm weather when you are painting. It can be thinned with regular tap water, unlike oil-based paints that can be only thinned with oil based paint thinner. If you are painting with a spray gun, it must be thinned because it is generally thicker than oil based paint.

 Paint thinning gives the paint the right viscosity for application. However, you must avoid over thinning. The following tips are for, how to thin paint to achieve a professional looking finish.  

Thinning latex paint tips:

1. Remove the paint can lid and pour the paint into a clean bucket.

2. If you have a large paint job planned, use at least a 5-gallon bucket for this project so all the paint will mix equally.

3. Add ½ cup of clean tap water for every gallon of paint.

4. Use a paint mixer or a stir stick to mix the paint thoroughly with the water until the paint and water is completely mixed.

5. Run the paint through a funnel. If it flows freely through the funnel, then it will flow through a sprayer nozzle without clogging.

6. Add more water if it does not pour through the funnel fluidly. 

7. Test the paint by applying some paint with a paint sprayer, paint roller or a paint brush to test the mix. Allow the paint to dry, and apply a second coat to get an accurate look at the thinned paint.