Spraying shellac in cold weather?

[Bob Johnson]

Can I spray Zinnser Sealcoat when it's 50 degrees in the garage? How long should I wait between coats?

Bob Johnson

[Bob Noles]

Bob,

Find a warmer area. I sprayed some in cooler weather not long ago and was not at all happy with the results.

[Steve Schoene]

Shellac will work in 50 degree temps since it doesn't depend on a chemical reaction to cure, BUT what it doesn't like, especially while spraying is high relative humidity. Too much humidity can lead to blushing and slow drying. Unfortunately, cool temps and higher humidity tend to go together, so the best way to ensure that the humidity levels are OK is to heat the space. I'd put a heater in the garage to warm up the project and the air, even though you may feel you are wasting heat, because you will need to have ventilation while you are spraying alcohol. Turn the heater off while spraying since the shellac fumes are flammable.

Cool weather also slows evaporation so you will need to wait longer between coats.