What causes dope to blush during application?

Blushing of dope during application is primarily caused by high humidity. When the relative humidity is high, water vapor from the air can become trapped in the film of wet dope as it dries. This moisture leads to a cloudy or milky appearance, known as blushing. The phenomenon occurs because the dope is essentially competing with the moisture in the air, which can disrupt the proper drying and curing process, affecting the finish quality.

While low temperatures can slow drying times and make finishes difficult to apply, they do not directly cause blushing. Direct sunlight exposure could cause uneven drying or overheating, but blushing specifically results from humidity. Using old or expired dope might result in other application issues, like poor adhesion or curing problems, rather than causing blushing directly. Understanding the influence of humidity on the drying properties of dope is critical for achieving a smooth, clear finish.