Sailboat Antifouling Paint

Which Antifouling Paint?

A Sailor’s Guide

There are over 100 different antifouling products available on the market, produced by up to a dozen different manufacturers, and as a poor innocent sailor your problem is to determine which one is best for your boat.

Unfortunately, the combinations and permutations of the different styles and types of antifouling available make an informed selection almost impossible for the average boat owner.

So let’s see if we can make a little sense out of the whole thing.

Firstly, there are basically two types of antifouling, hard and soft. And just to confuse you a little, soft can be very soft, soft, or not so soft.

hard antifoul

Hard antifouling paints usually have a hard, smooth finish that reduces water resistance and can be scrubbed by hand without sloughing off any paint into the water. Hard antifoul is a good choice for racing boats and trailer sailers where a hard finish that can take a few knocks and can be scrubbed is needed.

Interestingly, hard antifoul is also more eco-friendly than soft antifoul as very little of the active antifoul ingredient (usually copper in some form) gets into the water to poison the aquatic wildlife.

The downside with hard antifoul is that because the paint film does not slough off the layers of paint build up each year until you need to remove all the antifoul coats and start again from scratch. And removing several coats of hard antifoul is something you should leave to someone you don’t really like – if you can.

soft antifoul

Soft antifouling paints, called ablative copolymers, slowly slough off the paint film thereby exposing a new layers of antifoul material to repel the wildlife.

Soft antifoul is a good choice for cruising boats that are used regularly, as the boat needs to move through the water to slough off the paint layers. Because of this sloughing, the paint film slowly disappears over time. When recoating comes around, a pressure wash and rub down will probably be enough preparation for the new coat.

Some “Soft” antifoul paints can be quite hard, and the hardest types can be scrubbed and polished almost as well as the hard antifouls. “Soft“ soft antifouls are becoming less popular due to the amount of copper and biocides they release both during normal operations and each time they are scrubbed.

So what antifouling paint is right for you?

Luckily our old friends at Practical Sailor have done extensive 2 year research on the matter and analysis of their findings can be summarized as follows:

the best hard antifouls

The best hard antifoul are VC offshore by Interlux and Trinidad SR by Pettit
The best budget hard antifouls are Epoxycop by Interlux and Sea Bowld Coastal 45 by Blue Water

Other hard paints to perform well were:

Interlux’s Ultra
Pettit’s Super Premium, Unepoxy Plus and Vivid
West Marine’s Bottomshield
Sea Hawk’s Sharkskin

the best soft antifouls

The best ablative/copolymers are Micron 66 by Interlux and Biocop TF by Sea Hawk
The best budget ablative is Marpro Super-B Ablative by Blue Water

Other ablatives to perform well were:

Blue Water’s Coppershield 45
Interlux’s Micron CSC
Pettit ‘s Ultima SR
Blue Water’s Kolor
Interlux’s Trilux II
West Marine’s PCA Gold
Blue Water’s Sea Bowld Ablative 67 Pro

For aluminum hulls, Epaint’s ZO and Pettit’s Alumacoat are recommended

Prices can range from $65 per gallon to $230 per gallon, so check prices locally and with West Marine before you buy.

just wait a minute …

You thought it was as easy as getting the old paint ready for recoat and buying your new antifoul and slapping it on didn’t you?

Afraid not.

Some antifouls won’t play with others. You need to know what antifoul is on your boat already, and then check to see if your new antifoul is compatible.

Fortunately, most of the manufacturers have done their own tests and have this information available. To check, go to the manufacturer of your new antifoul (link below) and check if your old antifoul needs to be completely removed or whether a light sand will suffice.

Sea Hawk

Blue Water paints does not appear to have a compatibility chart..

handle with care

A few antifoul paints are water based, and the jury is still out on their effectiveness over time. Most other antifoul paints have strong solvents and harmful biocides in them and they need to be handled and used with caution. You will need to cover all exposed skin, wear gloves and especially good eye protection before you play with these. A cartridge type filter mask is also a very good idea.

Environmental protection rules have changed dramatically over the last few years, so if you intend to apply antifoul at your local marina or yacht club, talk to them first. Most facilities now have fairly stringent rules on how antifouling can be removed from the boat and how new coats can be applied.

You may find they no longer allow DIY antifoul work