Should you thin oil based paint?

Normally there is no need to thin oil based paint if you are applying it with a brush. If the oil based paint is old, it may have thickened over time and in that case you can thin it until it is at a consistancy which is easy to brush and gives good coverage. If you are spraying the paint you may want to thin it so it sprays easier from the gun. Thin then test and do it agoin until it sprays evenly from the gun. Normall "oil based" paints when thinned are with paint thinner. However always read the label on the paint for any instructions concerning thinning.