In fiber structure survey; hammer test, observation at different light angles, pH test, electronic humidity measurement and thermal camera are used. To reach a conclusion, the applied tests should be evaluated together and the entire structure should be considered comparatively. Moreover; It is important to measure and investigate other environmental variables such as ambient temperature, surface temperature, humidity in the air, dew point, duration of residence in water, duration of residence on land in order to reach a final evaluation.
"The high measurement you see in this picture is a shallow measurement, whereas it shows low at depth. No shallow measurements taken from the remaining fiber areas of the vessel were alarming. It is not correct to conclude that there is a structural defect in this region, based on this much information. What happens here is that high humidity measurements are taken as a result of the previous accumulation of sea water (it is dry now) and superficial moisture absorption through the already formed gelcoat cracks. (20°C). Before the survey, the water supply was cut off by intervention. It should be monitored, the area should be ventilated, measurements should be taken again in the future and the gelcoat should be repaired. "
As a result, the tests we have listed above, performed before purchasing, are non-destructive tests, and since we are trying to evaluate the durability of a structure that we cannot open and see inside, it is important to collect as many clues as possible. For example, core testing performed on reinforced concrete buildings is considered a destructive test.
The issue I am trying to underline in this article is that if the surveyor you have appointed simply points the electronic moisture measuring device at an area (as you can see in the picture) and takes high level measurements and then reaches the conclusion that there is osmosis there, it would be wise to approach such an approach and explanation with suspicion. Just so you know it will happen.
Moisture in the fiber structure is an issue that needs to be addressed on a level-by-level basis. The formation of osmotic bubbles or delamination between fiber layers is a situation that is quite advanced and may occur over a long period of time. Based on such a simple explanation, we recommend that you do not quickly give up on the boat you want to buy, while the expert I also recommend getting a second opinion from someone.
I would say that the issue of osmosis in a fiber boat should be approached cautiously.
Engin Mardin
Yacht Broker & Surveyor AffilIIMS