How to Spray Properly When It's Freezing Cold

Posted in Painting & Coating

The answer is: Use Heat!

By applying heat we reduce the viscosity of the paint. Viscosity is effectively the “thickness” of the paint and this is affected by temperature. Generally the higher the viscosity of the paint, the more film build you can achieve per coat of paint.

The most common solution is to use a high pressure fluid Viscon Heater. Utilizing heat can have other benefits besides just being able to spray in cold weather. Contractors often find that they are able to spray heavier (higher viscosity) coatings without needing to thin the paint, increasing their transfer rate.

Temperature Drop

Ambient temperature based on 21*C.
Typical temperature drop in fluid lines.

Temperature Viscosity of Paint Chart
Effect of Temperature on Viscosity


Maximum Temperature Rise vs Flow Rate

  • 4000W Viscon HP Heater with test fluid: 10W Hydraulic Oil
  • 2300W Viscon HP Heater with test fluid: 10W Hydraulic Oil
Graph Flow Rate

More handy paint heating tips:

  • Insulate your hose from the pump heater to the gun
  • Use a heated hose kit to keep your product warm as it travels to your gun
  • Use a drum blanket for wrapping a 208 litre drum
  • Use a rigid metal band heater for a 19 litre pail
  • Use a 208 litre drum plate heater
  • Store paint and spray equipment in a heated building/room