CASE 9
Antifouling
WHY IS IT IMPORTANT TO KEEP THE
UNDERWATER AREA OF A HULL FREE FROM
MARINE GROWTH?
Marine Growth may Damage the Structure
 A light Surface slime develops on new antifouling
in less than one Month
 If that slime is not removed small areas of weed
will also take hold
 Followed by Barnacles and other small organisms
 Growth will be more rapid as the antifouling
breaks down and allows the organisms to attach
themselves strongly to the hull surface
What is Antifouling?
 The traditional Antifouling is a paint
designed to protect the underwater
surface from marine growth
 It contains poisons (copper and tin)
 It is able to be applied by brush, roller,
traditional spraying, airless spray
 Think about the Health and Safety
aspects
Not all Antifouling works in the same way
 It can be soft, ablative and self leaching
 It can be a hard paint surface
 The purpose or use of the boat dictates which antifouling
type is chosen
 The metal content of the paint may determine the type of
antifouling to apply, depending on the substrate surface
of the hull (Galvanic corrosion)
 All boats that are permanently moored should be
antifouled
 Many Trailer boats are also antifouled, would they use
the same antifouling?
What is the effect on the Boat
 If the Hull is clean and growth free it is able to perform
as intended and take advantage of its own particular
design attributes
 All boats will travel through the water using less effort
A yacht will sail faster, a power boat will use considerably
less fuel
 In the case of a power boat the fuel savings could amount
to thousands of dollars in one season
 The effect of underwater growth on the performance of a
yacht will give the sailors no pleasure and add hours to
sailing passages.
Is the underwater hull itself the only problem?
 What about components such as propeller shaft,
rudder, skin fittings, Keel, Bow Thruster’s and
Stabilizers?
 What is the substrate surface that antifouling may be
applied to?
 How often are boats antifouled? And what about
water conditions, temperature, fresh or salt water,
and a tidal stream.
 Is Antifouling able to be safely sanded to apply a new
coat?
Health and Safety
In order to improve the sustainability of using a painted
antifouling regulations have been imposed on the handling of
antifouling from the cleaning of a hull to the application of
the paint with strict regulation regarding the manufacture
and toxicity of the paint. What do these regulations mean to
the Marine Industry?
There are brands of antifouling paint which have been
developed which are ECO friendly, one example of this is
Hydro coat (Petite) which is water based, copper free, and
contains a new additive, Econea.