3M™ Polyester Thinner is used to help thin body fillers to help reduce spreader drag, which can adversely affect the final results.

Achieve Better Filler Consistency
For best results with fillers in auto body repair, it's sometimes advisable to thin the filler with 3M Polyester Thinner. Body shop technicians commonly use thinner to get a smoother consistency, which reduces the occurrence of pinholes. Thinner may also be necessary when you need to spread a very thin coating of filler. This thinner is easy to use. Simply add a small amount of thinner and mix thoroughly. Keep adding until you achieve the result you desire. You should still use a normal amount of hardener with the filler.