Resin infusion

1. 22020sRelease Boatworks

First on record

RiserRelease Boatworks HIN RLB43001C323 · 2023

Latest on record

TiburonRelease Boatworks HIN RLB46006G425 · 2025

Resin infusion, also called vacuum infusion, is closed-mold fiberglass construction. It replaces the open-mold routine of crews in respirators working resin into the glass by hand with rollers and squeegees.^1,2

The method is not new. Maverick Boat Group began infusing its technical poling skiffs in 2000.²

The dry laminates, with Kevlar or carbon fiber if used, go into the mold with the core. A bag is sealed to the mold flange, and a vacuum drop test confirms there are no leaks.^1,4

Resin enters through 20 to 60 or more inlets fed from a manifold and is pulled through under vacuum. The process bonds the outer laminates, core and inner laminates into a composite sandwich. A 60-foot hull can be infused in a couple of hours.^1,4

Laying glass by hand often leaves excess resin, which adds weight but no strength. Infusion uses a predictable amount of resin and yields a higher glass ratio, for a stronger, lighter part.^1,2

The resin spreads evenly through the part, with no visible weak spots. Stringers, coring, transom and backing plates can be infused at the same time into one structure, and the fumes stay under the bag.²

Every shoot is a high-stakes investment in labor and materials. Bags can leak, the resin can fail to wet all the laminate, or it can gel before the shoot is complete.³

The process leaves waste: trimmed laminate, cured resin, flow media, peel ply and plastic bag material. And infusion alone does not guarantee a quality boat.^2,3