Sika SikaBiresin® AP077 Polyester Fairing Compound Above/Below Waterline - Quart

Sika SikaBiresin® AP077 Polyester Fairing Compound Above/Below Waterline is a professional-grade filler and fairing paste engineered for marine vessel repair, restoration, and finishing applications. Designed for both above and below waterline use, this compound delivers the smooth workability required by boat builders, marine contractors, and DIY restoration enthusiasts who demand reliable performance in demanding aquatic environments. The fast-set cure accelerates project timelines while maintaining the precision needed for high-quality surface preparation and aesthetics.

The formulation is a two-part polyester system requiring BPO (benzoyl peroxide) hardener, which initiates the cure process and enables predictable setting times for scheduling work. Unlike conventional fairing compounds, SikaBiresin® AP077 sands significantly easier, reducing labor time and tool wear during shaping and finishing phases. The quart size (3.3 lbs) provides practical coverage for moderate repairs, patching, and fairing operations without excess material waste. The paste consistency allows controlled application by trowel, putty knife, or brush, conforming seamlessly to hull contours, transom repairs, and seam filling.

Marine professionals and boat owners benefit most from this compound when addressing fiberglass cracks, impact damage, osmotic blistering, and cosmetic finishing on sailboats, powerboats, and commercial vessels. Full waterline approval—both above and below—eliminates the need for separate products across different hull zones. Before application, ensure hardener compatibility and follow Sika's mixing ratios for optimal cure time and hardness. Surface preparation and proper ventilation are essential for safety and performance; this product is ideal for use in shop, marine yard, or on-water repair contexts where professional durability and workability are non-negotiable.