Shrinkage

Cause

•   Topcoating before undercoats have thoroughly dried/cured.

•   Undercoats applied excessively wet with inadequate flash time between coats.

•   Undercoats under reduced.

•   Using a poor grade and/or too fast evaporating thinner/reducer for spray conditions.

•   Finishing over body filler that has not thoroughly cured.

•   Using too strong solvent cleaner or using thinner/reducer as a surface cleaner.

Repair

•   Allow the affected area to thoroughly dry/cure, sand and refinish.

•   If additional filling is necessary, apply a primer surfacer, sand smooth and refinish.

Prevention

•   Allow undercoats to thoroughly dry/cure before sanding and/or topcoating.

•   Thin or reduce undercoats according to product label directions. Apply in thin wet coats allowing adequate flash time between coats to avoid "bridging" scratches.

•   Select recommended thinner/reducer based on temperature, humidity, air movement, and size of repair.

•   Follow body filler manufacturer's recommended cure time.

•   Use solvent cleaner designated for either lacquer soluble or cured enamel/urethane insoluble substrate.