The trouble is that while the biocides
in the bottom paint deter the organism which foul the boat they also
have a detrimental effect other marine life and the very waters which
we use our boats to enjoy.
"Noah was a brave man to sail in a wooden boat with two termites."
Before buying an antifouling
paint do check the latest
regulations for your sailing area.
Copper is being banned by many
port authorities and even
scrubbing off is being legislated against in some areas.
A wooden boat that remains in the water all
year is going to need
antifoul bottom paint.
However, one which is regularly kept ashore won't need the same kind
fouling organisms survive in specific environments, salt water
organisms will die off in fresh water or in the air, so a boat which
regularly moves from one to the other may not need much if anything in
the way of protection.
And if you do antifoul, the choice of paint will also be influenced by
how and where you keep and use your boat.
amount of fouling can vary depending on temperature, salinity, water
quality and temperature as well as the amount of sunlight, the
and flow of the water and other pollution levels.
most fouling occurs along the waterline where it is encouraged by
sunlight it is regarded as good practice to apply an extra coat or two
here and on the rudder, however these are areas which are easy to scrub
clean with out the need to haul out.
And any water pollution on the surface can affect the efficiency of the
if you keep your boat in the water, check with your neighbours, the
marina and other boat users in your area to get an idea of the local
problems, and try to find the most effective but least toxic solution.
Types of Bottom Paint
The wide range of available antifouling paints
can be confusing.
Basically there are three main types;
Erodible or self polishing
And hard or Ablative.
While the active ingredients in all three
tend to be similar it is the
how they are put together that determines the type.
or self polishing;
In this type the active ingredients are suspended in a resin which will
once in the water begin to dissolve in a controlled way.
This allows fresh layers of the active biocides to be exposed on the
Traditional or Soft;
These tend to be cheaper than the more modern self polishing.
use a much more simple resin binder to hold the biocides, so while they
offer good cheap protection, they are not as efficient over the season.
The soft type need to be applied shortly before launching, so check the
instructions on the tin.
One disadvantage of the softer bottom paints is that they have to be
removed every so often due to build up.
Hard or ablative;
the name suggests these bottom paints are more resistant to abrasion.
As with the others the active ingredients are held within a resin,
however this is less soluble.
Ablatives use what is known as contact leaching which needs regular
movement through the water to be effective.
These paints are designed for high speed power boats, boats kept on a
mud berth and racing yachts.
Some other types;
based bottom paint is also available, has been developed for racing
yachts, however it is not particularly effective as an antifouling if
used without a biocide.
One part modified
epoxy paints tend to contain the highest biocide levels of
any antifouling paint.
are durable, abrasion resistant, however they are difficult to remove
and do gradually lose their effectiveness when out of water.
Water-based antifoulings encapsulate the biocides in a
water-soluble polymer resin.
They don't lose their effectiveness when the boat is hauled and
re-launched, and are reasonably easy to recoat.
While they use very little or no solvent and thus contain very few
volatile organic compounds, they do still contain toxins.
I am perfectly aware that the majority of Wooden Boat aficionados are sensible folk. However, I need to point out that I am an amateur wooden boat enthusiast simply writing in order to try to help other amateur wooden boat enthusiasts. And while I take every care to ensure that the information in DIY Wood Boat.com is correct, anyone acting on the information on this website does so at their own risk.