Cracking
APPEARANCE:
Paint film contains cracks of random size and degree characteristic of the wrinkles on a reptile’s skin.Also called checking, crazing, wrinkling or splitting.
CULPRITS:
There are several reasons why the checking, cracking, crazing, wrinkling and splitting of a paint film occur. They are:
- Excessive film thickness: Piling on too much material in full wet coats, either in the topcoat and undercoat material.
- Improper choice in reducer or hardener: It is important to follow a manufacturer’s suggestions on the type of reducers and hardeners to use with each paint. Improper or low quality materials may have an adverse effect on the finished dry paint film.
- Incorrect mixing ratio: If too much activator/hardener is used, or if the correct ratio is not properly mixed, defects may appear in the finished dried paint film.
- Extreme conditions: Excessive heat and/or humidity during and immediately following the application process can cause surface imperfections such as cracking, wrinkling, etc.
- Lifting of substrate: When the wrong reducer is used in a top-coat, or when certain materials are top-coated before achieving full cure, the undercoat may lift in a way that appears like cracking.
- Insufficient surface preparation: Cracking or other imperfections, if present on the substrate or existing finish, should be removed before the new material is applied.
TO FIX:
Allow paint film to cure completely, then sand out any imperfections and reapply material having made any necessary adjustments to avoid future cracking, checking, crazing, wrinkling or splitting.
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