Thurmalox 250 Selective Black Solar Collector Coating

Thurmalox 250 is a selective black silicone-based heat resistant coating designed for use on metal surfaces of solar collector panels. It selectively absorbs solar wave lengths with the greatest heat content (visible and infrared wave lengths) and therefore collects heat energy more efficiently than ordinary nonselective black paints which emit (reflect) a significant amount of incident solar radiation.

 Thurmalox 250 will function with maximum efficiency when used on collector panels having glazed covers. It is unaffected by high heat and humidity and exhibits no outgassing during stagnation periods. See Application and Technical Data sections for additional information.

In cases where a non-selective coating is required, Thurmalox 270 Black coating is recommended. See Bulletin 270 for details.

For unglazed collectors such as outside surfaces of passive houses and Trombe walls, use Endcor 902 Black Latex passive solar coating. See Bulletin 902 for details.


  • Selective surface
  • Resists outgassing to 400°F (204°C)
  • Heat resistant to 1,000°F (538°C)
  • Doesn't peel, flake or chalk
  • Won't bleach or discolor
  • Withstands repeated thermal cycling
  • Resistant to UV degradation
  • Dries for handling in 30 minutes
  • Air dry or heat cure
  • Long lasting
  • Available in 13 oz. (net wt.) aerosol cans


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Solar Collector Coating