Vulkem Primer #191 QD

Vulkem® Primer #191 QD is a quick drying, one-part, moisture-curing primer used as a urethane-to-urethane tie-in that prepares surfaces of cured Vulkem urethane sealants, coatings and membranes to be sealed with a fresh coat. 
 
Basic Uses
Porous surfaces, interlaminary, urethane sealants, coatings and TREMproof membranes. 
It is used to prepare surfaces of cured urethane sealants, coatings and TREMproof membranes that will be sealed with a fresh coat. 
Apply with a clean brush or roller. Do not apply in excess or allow to puddle. Use a short nap roller only. Dry time is 15 to 30 min at 70 °F (21˚C). 
Apply coating or sealant within 1 to 2 hr after application when primer is still tacky but does not come off substrate. Primer will yellow with time if left exposed. 
Do not apply in excess to other substrates not intended to be coated. Do not apply sealant or coating if primer becomes hard or glossy. 
If it does, clean with a Tremco approved solvent and reprime with Vulkem Primer #191 QD.