Quote Originally Posted by raul tuason View Post
The rainy day "bubble" myth

Car owners are hesitant to have their cars painted when its raining for fear of the dreaded "Bubbles" or "Blisters". This is not true. Generally, the weather has nothing to do with the bubbles or blisters on the car's paint but is always blamed for it. More often, the root cause of blisters is solvent popping caused by the paint sprayer who did not observe the correct flash-off time during the paint spraying stage. Flash-off simply means the allowance of time as specified by the paint manufacturer for the solvent or thinner to evaporate during the paint spraying stage.

In the painting process, a car is sprayed over with basecoat (color) and clearcoat (topcoat) a number of times. If the sprayer fails to observe the flash-off time in between coats, trapped solvents under the succeeding coats will find a way out creating microscopic bubbles.

These tiny holes become very evident during the rainy season when moisture enters the holes and manifests as blisters only to disappear when the sun shines and the moisture evaporates. The long-term effect of blistering is more damaging - as a result paint chipping and lifting will take place.

Cars refinished with Acrylic Lacquer (1K) are more susceptible to blistering. These type of paints have very low film build per coat (low opacity) , the sprayer has to do twice as much sprayovers thereby increasing the probability of failure to observe flash-off times.

In essence, paints are viscous; solvents and thinners are only vehicles for pain to be sprayed on a substrate or surface and should completely evaporate first during the drying process.
Very informative, thank you Sir Raul. Yung anggi ng ulan o spray of rain di ba nakakaapekto sa quality yun ser? Actually yun ang worry ko and flooding kasi sa Marikina yung mga prospect shops ko.