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TYPE SC and Type SC-1400
REDUCE GRAPHITE/CARBON OXIDATION
These water-based coatings result in hard, abrasion-resistant coatings that have high-emissivity and are usable on all graphites/carbons like ordinary housepaint. The TYPE SC coating inhibits graphite oxidation to its maximum recommended use-temperature of 1000 C, whereas TYPE SC 1400 provides protection extended to 1400 C and even to 1600 C for short-time use. Fired compositions of the coatings [TYPE SC listed first/ SC-1400, second]: 75%/72% silicon carbide; 8%/8% phosphorus oxide; 6%/6% alumina; 6%/6% silica; 5%/4% boron oxide; 0%/4% mullite. These compositions result on heating to above 600 C, at which point the coating is fully outgassed, whereas curing occurs by 350 C [i.e., a full-high hardness, water-resistant coating occurs at the cure temperature after approximately a 5-minute hold], and whereas some glazing occurs at 1100 C/1400 C for SC/SC-1400 coatings.
Both of these greenish-gray-colored coatings have a specific gravity of 1.85 and a pH of 2-3 in their liquid form – utilizing a sol gel suspension agent/binder. TYPE SC and TYPE SC-1400 have medium viscosity and can have a 300-400 sq.ft. per gallon coverage – generally painted onto a lightly-roughened, cleaned graphite surface as 2 to 3 brush-applied layers. It should be noted that, after the first coating, fast-brushing is needed to avoid rewetting/washing-off the first coating when applying additional coatings; or, the coating can be cured before applying additional coatings to avoid the rewetting/washing-off effects. While these coatings are designed for air usage, they are usable in all environments and are excellent in cyclic use.
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