Our hard tops are made of composite construction, or to use the common term, fiberglass. The generic term fiberglass covers a wide range of materials, and manufacturing processes used in the industry. At one end of the spectrum are chopper-gun polyester bathtubs, and at the other autoclaved pre-preg carbon fiber wings for a stealth bomber. Our production for the RV and marine sectors places us somewhere in the middle of these examples.
Ursa Minor uses two processes to form our parts, vacuum-infusion and open mold,
- In vacuum infusion, the core materials such as fiberglass cloth, honeycomb, carbon fiber and kevlar are placed into the mold in careful alignment. These materials are covered and vacuum drawn on the tool, followed by injection of the vinylester resin. Once the parts are cured, they are removed and trimmed to fit. The benefit of this approach is a light, uniform part with controlled weight and thickness, and very little wasted material.
- In open mold production, the fiberglass cloth is placed into the mold and the vinyl-ester resin applied by hand in layers. For complex forms the method is an effective way of building solid components.