Difference Between Acrylic & Polyester Boat Tops

A quality, custom fitting boat cover is an essential accessory for boat owners. When boats are stored for the winter, a custom fitting cover protects the top side fittings, wood and environmentally sensitive equipment. Boat covers are also used when boats are transported, or if they remain unused in the marina for an extended period. Different materials have unique properties, each of which have advantages and disadvantages.

  1. Woven Acrylic Canvas

    • Woven acrylic describes a fabric woven with acrylic fibers rather than cotton fibers. Woven acrylic canvas is a tightly woven fabric like it's canvas predecessor. Even through the material is waterproof, and still breathes because of it's woven composition. The acrylic fibers stand up to ultraviolet radiation from the sun better than other fabrics. It also resists mildew and staining better than cotton canvas. The colorfast material is available in a full spectrum of colors.

    Vinyl Coated Polyester

    • The vinyl-coated polyester materials are also waterproof, and a popular choice for boat covers. However, unlike traditional cotton and acrylic canvas, it doesn't breathe. Unless the cover is well ventilated, or air can circulate through the boat while in storage, condensation collects on the underside of the fabric. This condition eventually leads to mildew which begins the process of breaking down the fabric's integrity. Vinyl-coated fabrics are good choices for Bimini tops and sun shades over the passenger decks, but this product is generally less desirable for full boat enclosures, sail covers or sail bags.

    Advantages of Each

    • The chief advantage of the woven acrylic fabric is the combination of breathability and waterproofing qualities. The fabric allows condensation to escape from the enclosed/covered boat, while at the same time protecting the boat from rainfall and inclement weather. The chief advantage of the vinyl coated polyester comes from the fabric's superior waterproofing ability. The vinyl coating never looses its waterproof characteristics.

    Product Disadvantages

    • Woven Acrylic canvas has two negative characteristics. The first is the higher cost. The woven fabric is more expensive than cotton boat covers and vinyl covered polyester tarps. The second problem is the product's water repellency, which comes form a sprayed on chemical treatment. Acrylic tarps should be retreated every three to five years or they will lose the ability to shed water. The disadvantage of the vinyl covered polyester cover is the fabric's lack of breathability. A cover that does not let moisture escape can create problems inside the boat, including mold and mildew growth. Vinyl coated covers are also more sensitive to temperature. In cold temps, at and near freezing, the tarps become brittle and can crack or shatter in a stiff wind.