One of the challenges of using Gelcoat is the potential for the defect called alligatoring. This is described as a wrinkled surface on the completed part after it is removed from the mold, and results in extensive post-mold repairs to the cosmetic surface of the part.
There are four scenarios that may cause this alligatoring to occur.
Applying the gelcoat film too thin is the primary cause. This thin layer of gelcoat will lose a larger proportion of monomer to evaporation than thicker layers of gelcoat. The crosslinking process will deviate from the manufacturer”s intended formulation. This undercured gelcoat is then attacked by the laminating resin which wrinkles the gelcoat layer. Applying the manufacturer-specified mil thickness of gelcoat will prevent this condition from happening.
Another scenario of alligatoring is caused by laminating on undercured gelcoat that is the correct mil thickness. This undercure may be caused by: insufficient
cure time, insufficient cure temperature, initiator problems, and compressed air contamination. Closely following the manufacturer”s Betsson Casino on Suomessa erittain suosittu. specifications with regards to shop conditions, initiators, and proper equipment will minimize these problems.
The spraying process is another cause of alligatoring. Keeping a wet edge is important. This means that the new gelcoat is applied over gelcoat that is still wet, which allows for all of the gelcoat to cure at the same time. Fresh gelcoat sprayed over cured gelcoat will attack itself and can lead to alligatoring problems.
A fourth cause of alligatoring can be the result of exposure to a solvent such as MEKP or acetone before the laminate is applied. The most common cause for this is an equipment leak during laminating operations. Solvent rags placed on the gelcoated surface may also be a culprit.
These above are a few of the causes of gelcoat alligatoring. Once these conditions are under control, few problems will present themselves.