RETAIL OPERATIONS
Making the Best Choice There are four main methods of fiberglass manufacturing— which one is right for your forecourt products? BY ED KAMMERER
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here is a buffet of sorts for fuel retailers to choose from when they are outfitting their sites with components—such as manhole covers, an underground storage tank (UST) and dispenser sumps and covers, multiport access covers, top hats and skirts—that are constructed of fiberglass. A completely outfitted retail-fueling site will likely contain components that have been manufactured via one of four main fiberglass-production methods. All of them are viable and commonly used today, depending on the component that is being built. 22 | FMN Magazine SUMMER 2021
OPEN-MOLD SPRAY UP This method, also known as “chop and spray,” is the oldest. It utilizes a specialized spray gun with a bottle of resin to apply a pre-mixed, spooled fiberglass strand to a single-sided mold. In addition to its low cost, the main benefit of this method is that it is easier to produce parts that are of an irregular shape (not circular or square), as well as parts that are not meant to have an airtight or watertight seal or bear heavy loads and forces. The main drawback is that a part can only be produced with one smooth side, and the thickness can
be less consistent than those produced by other methods. It can also lead to an inconsistent blend of resin and glass fibers, causing weak or porous parts. Hand rollers are run over the surface to squeeze out any air pockets which can weaken the finished product. This process is labor and time intensive. RESIN-TRANSFER MOLDING (RTM) This construction method, which has been available for about two decades, uses a composite of glass fibers and resin that is packed into a mold, with the glass providing tensile strength and the resin contributing compressive strength to the finished product. All of the fiberglass fibers must be fully saturated with the resin to ensure a smooth, consistent finish on both sides of the object. This saturation is accomplished by layering the glass sheets into a mold and then injecting the mold with resin. FuelsMarketNews.com