The DiamondFinish Clear instructions page says:

Quote

Ideal application temperatures are 50-82°F (15-28°C). Use only in moderate to dry atmospheric conditions Avoid rainy or high heat/humidity conditions.

 

What humidity range is considerate "moderate" and what is considered "high" ?

 

DiamondFinish Clear is a moisture cured urethane which utilizes an advanced resin technology and in some ways behaves opposite of traditional solvent based paints and latex paints. If you want to speed up the cure of DiamondFinish Clear you will want to add humidity to the room where the surface coated with DiamondFinish Clear is curing. The curing temperature of the room should be between 55-82F and is fastest between 70-80F. The curing relative humidity of the room should be between 30-85% and the closer to 85%, the faster the cure for DiamondFinish Clear.

 

We commonly get questions in the winter because DiamondFinish Clear is curing slower than normal and that is almost always because the humidity is low. To get the humidity higher, wet the floor, wet some cardboard in the room, throw some wet towels on the floor, add a humidifier to the room or do whatever works for you and your situation.

 

NOTE: You can cure DiamondFinish Clear too fast which can affect the flow out of the brush or roller marks and also impact adhesion so please keep the curing atmosphere between 55-82F and 30-85% Relative Humidity for best results.