A Complete Guide to Mineral Spirits

Mineral spirits is the mild, everyday solvent most people already own without knowing its name. Sold as white spirit, paint thinner, or Stoddard solvent, it is the standard thinner for oil-based paint and the go-to brush cleaner in home and shop alike. It is worth knowing on its own, and worth comparing to a stronger aromatic like xylol (xylene).

The essentials:

• What it is: a refined petroleum distillate, a blend of aliphatic (straight-chain) hydrocarbons rather than a single compound.
• Strength: mild, gentler than xylene, toluene, or acetone.
• Smell: milder than the strong aromatic solvents, and odorless grades exist.
• Flash point: higher than xylene, roughly 40 °C, so it is flammable but less volatile.
• Mixing: like other petroleum solvents, it does not mix with water.

Its milder nature is exactly why it is the default for hand work. It thins oil-based paints, varnishes, and stains, cleans brushes and rollers, and degreases parts, all without the harshness of a strong solvent. That gentleness cuts both ways: mineral spirits is slower and weaker, so it struggles with cured coatings, heavy adhesives, and jobs where xylene’s punch is needed.

On safety it deserves the usual respect for a flammable petroleum solvent, though its higher flash point and lower toxicity make it easier to live with than the aromatics. Use it with ventilation, keep it off your skin and away from flame, and dispose of it as hazardous waste. The simple rule of thumb: reach for mineral spirits first for routine thinning and cleanup, and step up to xylol only when the milder solvent is not strong enough.