An aliphatic polyisocyanate in a solvent blend for use in Aero-Thane and UV-550 Urethane Varnish. Refer to directions on the base component listing.

Urethane Catalyst is furnished with Aero-Thane components as a kit. Urethane Catalyst is hydroscopic (sensitive to moisture) and will immediately start to polymerize in the presence of moisture. Therefore, it is very important the catalyst container cap be tight in storage. Containers are packaged with a nitrogen purge to eliminate moisture, and should be used as soon as possible after the cap is first removed and the nitrogen purge released. A milky appearance, gel in the bottom of the container, or swelling of the seals are indications of moisture reaction with the catalyst, and it should not be used because there will be no polymerization with the polyol (base component).

After each opening, the aluminum foil seal in the cap should be checked for damage and a new aluminum foil seal cut if necessary to prevent reaction with impurities in the paper gasket. The suitability of urethane catalyst can be checked by mixing 1 spoon to 3 spoons of the base component and brush a small test patch. After aging 7 days, rub 50 strokes with an MEK soaked rag. Any good quality, properly polymerized urethane coating will not be softened and the pigment transferred to the rag.


Guaranteed two years from date of manufacture, unopened in protected storage. Avoid extended storage above 100°F. Not affected by freezing.


Half-pints and quarts.