Removing old antifouling, preparing the hull, and selecting and applying the best fouling control may seem a daunting spring job for many DIY-ers, but Jason Hill, Technical Service Representative, AkzoNobel, says support from a specialist yacht coatings partner can help streamline pre-season maintenance so you are ready for launch.
Whether you look forward to it as an essential part of pre-season preparation or consider it an unwelcome hassle, the process of antifouling your boat is arguably the most important painting job for boat owners.
It is a task which involves overalls and other protective gear, appropriate tools, as well as meticulous preparation and application, but the rewards of effectively protecting your boat and preventing a fouled hull are immeasurable.
A smooth, clean hull, which minimises the attachment of fouling organisms, not only enhances the boat’s value and extends lifespan, but also increases fuel efficiency by reducing drag, therefore improving vessel performance and reducing harmful emissions. In addition, modern advances in antifouling protection contribute to the health of our marine environment by limiting the transfer of invasive species.
Prevention is much better than cure when it comes to the serious issues caused by barnacles, algae, mussels, weeds and slime adhering to the hull below the waterline, so the correct, well-applied protection is vital.
The good news is that with a few hours of dedicated effort on your boat’s antifouling after a winter ashore, you can feel safe in the knowledge that your efforts have resulted in a long-lasting sleek hull, which not only looks good aesthetically but achieves that satisfying extra knot of speed.
When the time comes to apply or reapply antifouling protection ready for a new season, the preparation, procedure and choice of products can be overwhelming. The antifouling process and products that suit each vessel will vary depending on several factors, including: the type of boat, the quality and material of the hull surface, the environment, the water quality and temperature, frequency of use and boating style, the periods between maintenance, and the priorities of the owner in terms of performance.
In light of these variables, the team of experts at AkzoNobel Yacht Coatings are on hand to assist in choosing the best solutions for your boat, in addition to offering the latest tips and techniques to ensure a stress-free application.
A GUIDE TO FOULING CONTROL: PREPARATION, PRIMING AND PROTECTION
As the weather warms up, spring is the perfect time to rejuvenate your boat after a winter ashore. To give your boat the highest level of protection, thorough preparation is key.
Before you tackle critical maintenance and the fouling control process, you will need appropriate personal protective equipment (PPE), including gloves, overalls with a hood and goggles or glasses, as well as a mask if you are removing old coatings. A tarpaulin is also recommended to place under the boat to collect scrapings and dust from sanding.
CLEAN AND INSPECT THE HULL
A thorough cleansing of the hull with a specialised cleaning product, such as International® Super Cleaner, will sweep off salt smears, as well as dirt and general grime. When flushing with fresh water, you can tell the surface is properly degreased when the water spreads across the surface without forming small droplets.
It is important to check the hull for signs of osmosis at this stage and treat any blisters that may weep a fluid resembling vinegar. Also, examine the keel and rudder for impact damage, cracks or where the coating may have become loose. Address and grind out the affected areas thoroughly and ensure they are fully dried out after treatment.
It is worth noting that if you are doing work on small repairs, it is recommended to apply a layer of primer before application of filler.
EVALUATE THE EXISTING FOULING CONTROL SYSTEM
If there is any peeling and flaking paint, an excessive build up or uneven surface, it is time to scrape it away. This type of flaking is likely to be caused by using fouling control paints that are not compatible with each other, or when too much paint has been applied over several seasons. You can save any layers that are in good condition.
We suggest using 80-120 grit sandpaper to sand any existing primer and frequently change the paper. Any bare substrate needs to be sanded with 80-120 grit to improve adhesion, unless it is aluminium or steel, which requires 60-80 grit sandpaper to remove oxidation. Always sand along the grain to avoid scratches.
SELECTING THE APPROPRIATE PRIMER AND FOULING CONTROL PAINT
When changing brands of fouling control products, consult compatibility charts to confirm that the new paint will adhere correctly. AkzoNobel offer a vinyl-based primer, Primocon®, that can be applied over most pre-existing coatings. Priming is a vital part of the painting process as it is the base on which the rest of the system will be applied.
When selecting the right fouling control, it is essential to consider your boat type and boating habits, as well as the specific fouling challenges and the local conditions in your area – including whether the water is brackish, fresh or sea water, and also taking into account water flow speed, tidal exchange and shading from trees or buildings. A key question to consider is whether you need hard or eroding antifouling.
If you have a fast boat, or for those who like to race, hard antifouling, which can be burnished or wet sanded to a smooth finish and does not wear easily, is a good option. Eroding antifoulings, also known as soft or ablative antifoulings, slowly erode in seawater. They offer very good all-round performance in a wide range of fouling conditions and suit those who prefer a low maintenance option. A sub-group of products known as self-polishing copolymer antifouling solutions are suitable for the harshest fouling areas and are ideal for larger vessels that require longer periods between maintenance, as well as increased all-round performance.
International® fouling control provides protection for all types of boats, in all waters and conditions, to stop barnacles, worms, slime and algae from settling, which increases drag. The Micron® range is specifically formulated to release just the right amount of active ingredients to keep the surface clean throughout the season, without the need to scrub your boat between applications.
When selecting the right solution for your boat, consider if you need an advanced self-polishing copolymer suitable for the harshest fouling areas, or solutions which are effective against medium fouling or lighter fouling areas, or perhaps you are looking for a hard racing finish. As a general guide, Micron 350 is an advanced self-polishing copolymer for the harshest fouling areas; Micron 300, Cruiser 250 and Cruiser 200 are effective against medium fouling; Boatguard 100 is for lighter fouling areas; Ultra 300, Hard Antifouling and VC Offshore EU for hard racing finish.
APPLY PRIMER AND FOULING CONTROL TO THE HULL AND AUXILIARY PROPULSION
On a still, windless day, mask off the areas that are not going to be painted, such as topsides on the waterline. Once taped, mix your paint following the recommendations on the label or technical data sheet, and add solvents where necessary to aid application or improve adhesion if applying your first coat of paint onto bare wood.
Ensure that the interval time between the end of the application of the epoxy primer and the first coat of antifouling is no longer than stated on the datasheet or label.
Antifouling paints are formulated to be applied as they are, so there is no need to add thinners. However, there are some occasions where a small amount of solvent can be added to aid application.
Applying paint with a roller is a fast method of covering large areas, with brushes best used for small areas. If you are applying product with a brush, a good technique is the criss-cross method with paint applied to the surface with diagonal brushing from left to right. Spread the paint further with horizontal strokes before finally laying off with light vertical strokes to ensure a uniform layer of paint. Apply sufficient paint for the product to flow, but not so much to make it sag or run as it can be hard to remove them later.
In particularly hot or cold weather conditions, a small amount of suitable thinner can ease the application.
Follow immersion times carefully to avoid detachment, blistering or cracking of the fouling control. It is good practice to apply an extra coat to leading and trailing edges such as the waterline, trim tabs, outdrives, keels and rudders, which experience more water flow and turbulence.
Don’t forget to antifoul your propeller. AkzoNobel offer a quick-drying one-part primer, International Propeller Primer, with excellent adhesion properties which works in combination with our recommended International antifouling, forming a unified coating system that resists dynamic and cavitation forces to protect propellers and underwater metals from fouling build up.
ENSURE SUPPORT FROM AN EXPERT PARTNER
Before you tackle the task of fouling control or other painting tasks, it is best to seek advice from trusted experts if you are in any doubt about how to proceed.
AkzoNobel Yacht Coatings advisers are available to help you select the most appropriate solutions for hull protection and fouling control. AkzoNobel Yacht Coatings can provide customers with access to the latest advice on product selection, application guidance and technical support on coating application for both above and below the waterline.
Boatowners can also refer to International® Boat Paint Guides to select the right fouling control paint based on local conditions and boat type.
