OPTICAL CHARACTERISTICS

    SOLKOTE is both thickness and substrate dependent. Ideal optical qualities for solar thermal applications are best achieved by applying a thin coat on low emissivity substrates such as aluminum, copper or stainless steel. Emissivity can range from .28 - .49, and absorptivity from .88 - .94, depending on the substrate and thickness of the dried film. Passive applications on cementitious substrates will yield high absorptivities but only moderate selectivity. Thicker applications on metallic substrates will yield high absorptivities and excellent radiation properties for radiant heating applications.

WAVELENGTH REFLECTANCE CHARTS

SOLKOTE HI/SORB-II on Stainless Steel

AISI 304 Stainless Steel was dip-coated in SOLKOTE HI/SORB-II. After each coat, solar and infrared hemispherical reflectances were measured to calculate solar absorptance: a, and thermal emittance: e (400ºC).

SURFACE PREPARATION-METALLIC SUBSTRATES

    Surface preparation on metallic substrates is extremely important. Not only does a clean substrate enhance adhesion, it also lowers emissivity and improves overall optical properties. SOLKOTE exhibits excellent adhesion on many substrates with little or no surface preparation, however, the following procedures are suggested to insure the excellent optical properties and long term durability available from this product.

SURFACE PREPARATION-PASSIVE APPLICATIONS

    Masonry substrates for passive applications should be air cured for at least one month prior to application of SOLKOTE. Surface should be free of all paint, loose grout and dust. SOLKOTE has a natural affinity for most masonry and ceramic surfaces, but is extremely thin. Suitable primers or fillers may be used to extend coverage. SOLKOTE will yield a highly absorptive and long lived surface on cementitious substrates, but selectivity will be limited.

APPLICATIONS

    SOLKOTE has been formulated specifically for air atomization spray application. Simple spray guns normally used in automotive body repair facilities have proven to be quite adequate for application. Electrostatic and HVLP equipment is also excellent but substantially more expensive. Gun pressures should be kept fairly low to lessen overspray and allow good thickness control. Remote pressure supply pots should have air driven agitators and the coating should be mixed as often as is practical during application. A wet film thickness of .8 – 1.0 mils (.02 - .025mm) is ideal and may be easily measured using a wet film thickness gauge during application. The coating should just cover the substrate and when dry, it may be possible to barely see the substrate through the dry film.Airless application equipment is not recommended and substrate temperatures should not exceed 90°F (32°C) during application. Good ventilation and operator protection is imperative.

    Any application questions not covered above may be referred to us by email for response from our Technical Services Department.

DRYING and CURING

       Curing is highly dependent upon substrate type and ambient temperature. Skin forms within 2-5 minutes; coated absorber may normally be handled after 1-3 hours drying at room temperature. SOLKOTE will naturally cure, to a point where no outgassing will occur, within 3 days at room temperature of 60^°F (16^°C) or above. Curing may be easily accelerated by baking the coated absorber panel at temperatures ranging from 225^°F (107^°C) to 450^°F (232^°C) for a period of 15 minutes to one hour. Copper should not be cured at temperatures above 400^°F (204^°C) as it will oxidize and cause a decrease in coating adhesion. However, other metals, such as aluminum and stainless steel may be cured at temperatures up to 450^°F (232^°C). Coated absorber plates may also be placed in bright sunlight to accelerate curing. Experimentation will determine the best curing procedures for your particular environment.

PACKAGING, SHIPPING, PRICING

SOLKOTE: Available in 1 Gallon and 5 Gallon steel pails

   Weights and Volumes:

                    1 Gallons (3.785 Liters) - 8.2 lbs (3.73 Kg)

                    5 Gallons (18.925 Liters) - 42.5 lbs (19.32 Kg)

*Flammable Liquid n.o.s., Class 3, UN1993, Packing Group III

*All packaging is certified for air freight and available for export. All freight charges FOB Ewing, NJ. Packaging charges are extra and not included in our pricing schedule. MSDS information available upon request. Contact factory for pricing via email, fax or phone.