Applying Coppercoat antifouling


s with any coating, preparation is the key, so the surface should be thoroughly cleaned prior to application. Coppercoat can be applied directly to gelcoat


Preparation A


provided that all paint, dirt, dust, grease etc is removed first. For wood, iron, steel, aluminium and ferro-cement an appropriate epoxy primer must be used before applying the Coppercoat. On a larger craft, preparation often takes the


form of using sand or slurry blasting carried out by a contractor. Here, a low-pressure compressor delivers high volumes of abrasive particles at a hull to remove previous coatings. My project would be on a more manageable scale, so once I had scraped off loose paint and contaminants such as the residue of stubborn barnacles etc I sanded down my hull with 120-grit wet and dry abrasive paper used wet. When clean, I left the hull to dry for a few days then wiped it down with isopropanol – don’t used oil-based products or acetone for this job.


was told that to get even coverage and a smooth finish for this job, Coppercoat should be applied in five thin and equal coats. All coats should be applied consecutively in a


Mixing the gloop I


single day to ensure a satisfactory chemical bond between the coats. It was recommended that I divide the pack into five equal parts, and for each coat to mix 100g of epoxy with 100g of hardener and 400g of copper powder. This can be done by volume using containers, or in my case I pre-weighed the powder and put it into separate packets for convenience. Because Coppercoat is water-based,


the cure rate is affected by temperature, humidity and airflow. Therefore, it should not be applied if the ambient temperature is below 8°C. Ideally, the advice is to apply it on a warm day with a little airflow and a time gap of approximately an hour between coats. However, as I was coating my tender in winter I was able to bring it undercover in the garage and use heaters to raise the air temperature.


A litre pack of Coppercoat contains 500ml of hardener, 500ml of resin and 2kg of copper powder


1 The first job was to thoroughly clean the old paint.


the hull and remove what remained of


1 The copper powder is very fine so it is easily absorbed into the epoxy mix.


2 On this small project, weighing out the quantities of copper powder


beforehand helped when making up the resin mixes.


4 Short-pile rollers 3 For coating my tender I prepared five packs of copper powder each weighing 200g.


2 Masking tape was used to mark the wet-abraded with 120-grit paper.


waterline, and the gelcoat was then


(shown) or high-quality


foam rollers can be used for applying the Coppercoat.


3 When dry, the hull was wiped down use acetone.


with isopropanol solvent – do not


5 The mix can be calculated by volume, out into a clean, dry mixing pot.


but here 100g of resin was weighed Practical Boat Owner 585 April 2015 • www.pbo.co.uk


6 100g of hardener was then added using digital scales.


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