Background: Fiberglass reinforced plastic (FRP) is used extensively in the boating industry for both work boats and recreational craft. Boat manufacturers and marine surveyors need to obtain accurate hull thickness measurements. In the past, unless there was a place to put a micrometer, there was no way to determine thickness except to drill a hole in the hull. Modern ultrasonic thickness gages, however, make it easy to check the thickness of boat hulls.
Gelcoat measurement: A closely related application is measuring the smooth gelcoat applied over fiberglass. For detailed information on ultrasonic measurement of gelcoat thickness, please refer to the separate application note Measurement of Fiberglass Gelcoat. |