Available sizes

• Aerosol
• Quart
• 1 Gallon

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

• Solar Collector Panels

OEM-250

Black

1000°F (538°C)

Ambient to 500°F (260°C)

1

20%

Per Gallon: 320 mil. sq. ft. (7.9 sq. m. / liter)

50-120°F (10-49°C) max. - Spray cans, 75°F (24°C) max.

10-15 minutes

81°F (27°C)

Heat cure at 350°-400°F for 1 hour

Per Gallon: 9.24 lbs. (1.1 kg/liter)

Aluminum: Prepare surface with Endcor 450 Rust Rinse (see Bulletin 450). Wash thoroughly with water and dry. Apply Thurmalox 250 as noted below.

Stainless Steel and Copper: Remove oils and grease by wiping down surface with Dampney 170 Clean-up Thinner.

Redisperse any settled-out pigments by stirring with a paint paddle followed by thorough mixing to a uniform consistency with an explosion-proof or air-driven power mixer. Do not open containers until ready to use. Keep lid on container when not in use.

Do not apply Thurmalox 250 without thinning. The choice of thinner will influence the coating's average selective characteristics. For optimum selectivity, a slow-evaporating thinner such as Dampney 100 should be used. For production line application where a faster dry time is required, use Dampney 110 Thinner. The fastest thinner available is Dampney 140. NOTE: Fast-evaporating thinners such as Dampney 110 and 140 may promote dry spray, which could result in thicker than recommended films. To ensure the optimum combination of application speed and selective properties, consult your nearest Dampney representative for specific recommendations.

Clean all equipment with Dampney 10 Clean-up, or Thinner, or xylol.