GRP is the most widely used, and is generally regarded as the ideal construction material. Its is not without it’s problems however. Osmosis is not the fatal affliction that is was once thought to be. It is often little more than a cosmetic issue and can be repaired relatively inexpensively. In a pre-purchase survey, however, its is important to identify early signs of a hulls likelihood to develop blistering in order for the cost of repair to be reflected in the buying price.
The hull bottom is the subject of an extensive examination for moisture content, blistering, de-lamination and consolidation of the laminates. Moisture content is measured with a Sovereign Quantum Moisture Meter. This is the industry standard monitoring device and is a capacitance type tester which can read deep into the laminate. Testing is also carried out with a Tramex Skipper Gen 5 meter. This is also a capacitance type tester but is rather easier to use being a single handed unit and includes data logging functions that records via Bluetooth to a mobile phone. The two devices can be used to double check readings and avoid spurious errors.
The hull bottom is also percussion tested all over with a small pin hammer to eliminate the possibility of blistering or de-lamination. The topsides are tested with a Barcol Impresser. This tests the hardness and consolidation of the laminates. It can also establish the level of cure in new GRP. Gel coat hardness and the level of oxidisation and UV degradation can be measured with a Shore D Durometer. These measuring devices can also identify poorly executed repairs.
The vessels systems, engineering and equipment are fully examined and tested where possible. Below is a sample survey of a GRP yacht which will show the full scope and depth of the survey report.
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