Resin Additives, Rollers, Spreaders, Etc
What Are Resin Additives, Rollers & Spreaders?
Whether you are patching a cracked hull, rebuilding a rotted deck section, or laminating new fiberglass onto a damaged panel, having the right application tools and additives is just as important as using quality resin. Resin additives, rollers, and spreaders are the unsung heroes of any fiberglass or composite repair job — they ensure proper resin wet-out, eliminate trapped air bubbles, and give you a smooth, structurally sound finish that lasts.
Spreaders allow you to apply body filler and polyester or epoxy resin in a fast, controlled manner, working the material into every corner without wasting product. Rollers are essential when laminating fiberglass cloth or mat, evenly saturating each layer and consolidating the laminate to drive out voids and air pockets that would weaken the repair. Resin additives — such as surfacing agents, thickeners, and wax-based solutions — modify cure characteristics, improve sandability, and help achieve the surface quality you need before finishing.
Key Considerations When Shopping
- Compatibility: Confirm your roller covers, spreaders, and additives are rated for the resin system you are using — whether polyester, vinyl ester, or epoxy. Solvent-resistant cores are essential for anything beyond light-duty use.
- Roller Nap: Shorter nap rollers (1/8" to 3/16") are ideal for thin resins and smooth surfaces, while slightly thicker naps work better for textured or porous substrates.
- Spreader Flexibility: Flexible plastic spreaders conform to curved surfaces and make it easier to feather edges on body filler and resin work without gouging.
- Additives for Surface Cure: Wax-based surfacing agents mixed into polyester resin help the surface cure tack-free, making sanding much easier after the repair hardens.
Top Brands in Resin Additives, Rollers & Spreaders
Evercoat is one of the most widely trusted names in fiberglass repair, offering everything from complete repair kits to individual spreader sets. Evercoat's flexible plastic spreaders are specifically engineered for fast, smooth application of resins and body fillers, and their repair kits come bundled with the cloth, hardener, and application tools needed to tackle a wide range of jobs on fiberglass, metal, and wood surfaces.
Hi Bond is a marine-focused brand that brings a deep understanding of boat yard needs to its resin additive lineup. Hi Bond offers specialty additives such as surfacing agents for polyester resins and gel coats that create a less tacky surface for easier sanding, as well as thickening agents like Cab-O-Sil that allow you to build high-strength putties tailored to your repair.
Redtree has earned a strong reputation among marine professionals and serious DIYers for their purpose-built fiberglass resin rollers. Redtree roller covers feature solvent-resistant phenolic cores and are designed to spread resin evenly without leaving air pockets or bubbles — and in many cases they reduce or eliminate the need for a separate metal consolidation roller, saving time and effort on multi-layer laminating jobs.