Gelcoat and other polyester resins have a high risk of incompatibility when applied to certain epoxy substrates, including epoxy fairing compounds such as TotalBoat TotalFair.
DO NOT apply gelcoat directly to cured TotalFair, or the gelcoat will not cure properly.
Before applying gelcoat, the substrate must be properly prepared, and the TotalFair must be overcoated with an epoxy barrier coat or epoxy surfacing primer, such as TotalBoat TotalProtect. Follow the steps below with extreme attention to detail to ensure proper adhesion and cure of all products. Do not make substitutions or cut corners in any of the surface preparation or application directions.
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Apply TotalFair as directed, following all surface preparation and application directions with great care.
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Once the TotalFair has fully cured, but before it is sanded, wash the TotalFair with a mild soap and warm water. A sponge or abrasive pad can be used.
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Sand the surface fair, or smooth, as desired, with 80-grit sandpaper.
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Remove all sanding residue and apply TotalBoat TotalProtect or similar epoxy primer, as directed.
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Allow the TotalProtect or epoxy primer to cure for 5-7 days, under normal curing conditions.
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Wash the fully cured TotalProtect or epoxy primer with a mild soap and warm water, then rinse it thoroughly.
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Allow the surface to dry completely, and sand the surface smooth with 80-grit sandpaper.
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Wipe the surface clean with a clean, lint-free cotton rag dampened with acetone. Follow by wiping the surface with a clean, dry, lint-free cotton rag. Do not use synthetic rags, as they will leave a residue behind, which will prevent the gelcoat from curing or adhering as it should.
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Apply TotalBoat Gelcoat, as directed under normal cure conditions. Take care to ensure the gelcoat is properly catalyzed for the ambient conditions.