Use no thicker than 1/4″ when apply to cure properly, ideal cure temp is 60° to 80°F for up to 24 hours. Will adhere to metal (even aluminum)- scuff metal surface and clean well with Lacquer thinner before application. Clean up excess using a damp cloth before it dries, can use a little water if dried out in the tub. Can set a ‘small’ fire to help set cure *BUT* not too hot or can boil the water out of formula, causing holes and cracks that will compromise the application, paint-able once fully cured. Interior use only, the product is water-soluble, not flexible (dries hard cement) this can cause cracking on stove pipes that expand and contract with heat, use a silicone sealant or direct vent sealant depending on temp in these cases. If you need a higher temp rating to use Refractory cement. color may whiten when heated. Not an adhesive and is water-soluble. if need to adhere firebricks to cinder block use Castable Refractory Cement instead.