The main symptom - blisters Blisters are the most common warning sign and if identified should be followed up with immediate professional examination. Blisters can vary from being small pinheads, to blisters to as large as the palm of your hand. The presence of any fluid behind a blister indicates a potential problem. If the fluid has a pungent, vinegary odor or feels greasy or sticky when rubbed between the forefinger and thumb, there is a high probability of osmotic damage. Before any treatment is done, we recommend that you seek the advice of a professional boat surveyor to give you an assessment of the damage and what will need to be done to correct the problem.
Some blisters occur for reasons other than osmosis.
These blisters are hard and difficult to break and when broken open will be dry, with no odor evident. The likely cause is air voids. This is not a serious problem, but the hull moisture levels should be checked before commencing remedial treatment. Crazing - This effect can occur where the gelcoat is brittle. Fine cracks usually form due to severe flexing or impact damage, allowing water to seep into the laminate.