I have discussed fiberglass' problems several times on Nautica with several articles on osmosis , a chemical phenomenon which is sometimes appointed as the only fiberglass' disease. Osmosis is , in my opinion, the most important fiberglass' defect which can, on the other hand, be easily repaired with expensive but effective cures. This vice is, however, not always easy to find, as some of you can remember from the previous articles on this matter. If, for instance, walking on deck we can detect a clear unusual bending, most likely it is due to delamination which has occurred due to a foam core damage or to the separation of the skin from the core material.
Lets now analyze what happen when delamination occur.
The outer layer is usually thicker. The core material do not cover the entire hull surface and, in way of engine girder, deck fittings and chain plates is replaced by single skin laminate. This is done to overcome the low compressive strength of core material, which can fail under concentrated loads, such as bolts. Sandwich delamination occur when one of the two fiberglass layers separate from the core material. Delamination may occur in unusual ways as well.