What is the difference between mineral spirits, paint thinner, and turpentine? Can they be used interchangeably for cleaning brushes or thinning oil-based finishes?
The least expensive of the three, paint thinner is often made from reclaimed mineral spirits, so trace impurities prevent the manufacturer from labeling it purely as mineral spirits. But you’ll notice little difference in the way they perform. Because of the strong odor of both, you may prefer to pay a little extra for odorless mineral spirits, which has had some of the smellier parts chemically extracted. This weakens it slightly as a solvent. Derived from the sap of pine trees, turpentine has a noticeably stronger “piney” smell than mineral spirits or paint thinner and is the stronger solvent for cleaning brushes. It also evaporates faster in thinned finishes, leaving less “open” time before the finish turns tacky. But it can be used in place of mineral spirits or paint thinner with no other noticeable difference.