Fairing Compounds

What Is a Fairing Compound?

Fairing is the process of making a boat's surface geometrically true and smooth. Fairing compounds — sometimes called fairing putties — are the workhorses of that process. Fairing a surface means smoothing it out, which can involve filling low spots or holes, or sanding and grinding down bumps until the surface is level. The material used for filling or shaping is called a fairing compound or fairing putty, which contains some type of resin — either epoxy, polyester, or vinyl ester.

A fairing compound fills low spots, seams, and minor imperfections, preparing the substrate for primers and topcoats. Beyond cosmetics, a properly faired hull has real performance implications: applying fairing compound to your boat can increase speed by reducing drag on the hull. Whether you are chasing a racing podium or simply want a clean, professional finish after a season of hard use, fairing compounds are an essential part of the marine maintenance toolkit.

Epoxy vs. Polyester Fairing Compounds

Fairing compounds contain some type of resin — epoxy, polyester, or vinyl ester. Epoxy-based compounds are the go-to choice for most modern applications: they bond aggressively to fiberglass, wood, aluminum, and steel, resist moisture absorption, and resist shrinking after cure. Polyester-based compounds are often more economical and are a practical option for above-waterline cosmetic repairs. There are also single-component surfacing putty fairing compounds that are not epoxy or polyester resin based — this type of fast-drying surfacing putty is used above the waterline to fill fastener holes and shallow gouges and to fair minor imperfections in fiberglass or bare wood prior to painting.

Key Considerations When Shopping

• Above vs. below the waterline: Determine if the repair is above or below the waterline before selecting a product — not all compounds are rated for constant submersion.
• Substrate compatibility: Fairing compounds vary in their suitability for fiberglass, wood, aluminum, and steel. Always confirm compatibility before applying.
• Brand compatibility: If you know you are going to be using a specific paint, it makes sense to use the same brand's fairing compound. Because paint failure has dire consequences, each paint maker tests how various layers in the filler-primer-topcoat regime interact.
• Cure speed and working time: Some fairing compounds can be used with either a standard or fast cure catalyst to provide maximum flexibility for application in a variety of conditions.

Top Brands in Marine Fairing Compounds

Pettit Paint is one of the most trusted names in marine coatings, and their fairing lineup reflects that expertise. Pettit's EZ-Fair epoxy fairing compound is a lightweight, two-part epoxy putty designed for filling and smoothing surface imperfections above and below the waterline. The special resins used in EZ-Fair impart a high degree of water and chemical resistance, making it an integral part of the Pettit Gelcoat Blister Repair System.

Interlux Paint brings a comprehensive, professionally-oriented approach to fairing. Interlux was the only company in one independent comparison to offer a full range of pre-thickened fairing products to be used with a complete line of paints and primers. Their flagship Interfill 830 is a standout: it has extremely low density and is one of the lightest yacht epoxy fillers available in the marketplace.

Awlgrip is synonymous with premium yacht finishes, and their fairing products are engineered to integrate seamlessly with their high-performance topcoat systems. A professional-quality makeover with sprayed-on Awlgrip paint is the benchmark of topside refinishing, and using Awlgrip fairing compounds ensures complete system compatibility from bare hull to gloss topcoat.

Sika is a globally recognized leader in adhesives, sealants, and specialty compounds. Their marine fairing and seam products leverage Sika's deep expertise in polymer chemistry, making them a reliable choice where structural integrity and long-term flexibility matter alongside a smooth surface finish.