Wood rots - steel rusts - GFK gets osmosis. Whereas in wood and steel
it usually takes some time, osmosis can occur on fiberglass hulls at
any time. As a rule, risk factor is: the warmer the ambient fluid, the
lower the density, the greater the risk of osmosis. This explains why
the risk of osmosis in the Mediterranean is about twice as large as in
Baltic and North Sea - and in the Caribbean twice as large as in the
The manufacturing process decides whether a fiberglass boat gets
osmosis or not. The reason are small bubbles between laminate and
gelcoat that may arise during production. These bubbles fill with time
with water molecules, the bubble grows and the gel coat stands out
from the laminate. If the process is not stopped in time, the entire
laminate can be affected and may become unstable in the extreme.
Identified early, osmosis can, however, be stopped with modern
techniques and materials. For this purpose, the affected gelcoat is
removed and rebuilt with a substitute. This requieres several
operations. This work is our daily bread, we have plenty of experience
with it. An osmosis ckeck therefore is part of our standard program.
Don’t believe self-proclaimed hobby specialists scaring you with
rumors that osmosis is the death of your yacht. It is only important
that the first signs of osmosis to be detected in time, before major
damage occurs - and that it is treated consistently and professionally.