Antifoul your boat the right way

Antifouling - getting it right

Antifouling is an important part of owning a boat. Lots of people carry out their own antifouling at the start of the season – it can be a pretty miserable task during the dark days of winter – but it’s a must for protecting the hull of your boat from the very harmful effects fouling on the hull can have.

Heavy fouling can make your boat slower, less responsive and difficult to manoeuvre in tight spots and it doesn’t look great either.

So where do you start?

Preparation, preparation, preparation.

First job, make sure you have everything you need. The correct antifoul for your circumstances – sea going or inland, the right colour paint, brushes, trays, masking tape, rollers, sheets, protective clothing and equipment.

Always make sure the area you’re working in is well ventilated – normally you’ll be outside on a hard standing so this shouldn’t be a problem. Choose a dry day for applying the antifoul as wet weather, even damp air can affect the bonding properties of the antifoul.

Dress appropriately – ok you might not look very cool but wearing protective clothing is recommended. Wear glasses or goggles to protect your eyes, disposable overalls are a great idea.

Before you start, just after your boat has been lifted and scrubbed have a good look around the hull. Make checks for even the smallest damage and the severity of fouling. Use a scraper to take off any paint that’s coming away or any troublesome spots of fouling but be careful not to scratch the surface of the boat.

The hull of your boat needs to be completely dry before you start. Make sure it’s clean and doesn’t have any oil or grease on it. Be careful when sanding down old antifoul – the dust is toxic so wet sand only and capture the residue which you should treat as hazardous waste. Under no circumstances dry sand old antifoul.

You should use an underwater primer to completely bare hulls before antifouling. Choose the correct primer for your circumstances, and always read the label first. Pay special attention to the length of time you need to leave between coats and drying times. Using a roller is the best way to apply primer to large areas, then use a brush to touch up on smaller areas.

Existing antifoulings don’t normally need special preparation. Have a look for any small lumps in the paintwork and wet sand them down if necessary.

Before applying the antifoul read the label on the tin for advice on drying times, number of coats and note the health and safety information. There will also be a note on the tin that tells you the maximum length of time you can leave before launching your boat back in the water.

Stick the masking tape around the waterline of your boat and mask off the anodes, shafts and fittings to protect them whilst painting. Put down a protective sheet on the ground when you’re working. Antifoul has a tendency to settle so make sure you stir it properly before starting and regularly during application – it’s best to use a flat blade to do this. Make sure you’ve got enough paint to do the whole job – you don’t want to run out half way through.

When you’re ready to start applying the antifoul pour from the can into a tray – keep the lid on the can between filling the tray for the best results. If the temperature drops you might need to get some warm water in a bucket and stand the can in it to continue applying the antifoul with the same smooth finish. The best way to apply the antifoul is with a mohair roller for the most part and then using a brush to touch up fiddly areas. Roll the antifoul in a criss-cross pattern, just as you would if you were using a brush. This will give you a nice, even finish. Don’t smoke or eat during painting.

Once you’ve finished apply extra layers to areas that are more prone to wearing, this will be around the waterline area and leading edges, the rudder, keel and trailing edges. You boat will be subject to more water flow here and needs a bit of extra protection.

When you’re all done and the antifoul is starting to dry, remove the masking tape – don’t wait until the paint’s dry as this could give you an edge that doesn’t sit flush with the hull. Try not to finish at the very end of the day as the night draws in as the risk of dampness and dew will spoil the look of your antifoul and may even affect its performance.

The last thing to do is tidy up, keep your cans sealed and dispose of them properly as waste paint at a recycling centre – the copper which is present in most antifouls can be harmful to marine wildlife so be responsible and dispose of your can in the proper way.