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  • Writer's pictureSailing The Dream

Coppercoat antifoul treatment - considerations and costs (part 1)

Since we bought The Dream way back in 2016, we wanted a more efficient option for the antifoul treatment and one that does not have the toxic footprint of the most commonly used treatments.

Our research back then pointed us towards Coppercoat, however by the time we splashed The Dream and moved on board in early summer 2017 our minds still had a few doubts.

First and foremost, price.

At that time we decided it was more important to get back on the water fast and out of the dock to test our new lifestyle before committing to yet another expensive decision (we did quite a few expensive upgrades on those first months that we thought were essential to us). We splashed two new coats of the International antifoul paint called Micron Extra and decided that before our next haul out we would make a decision on this topic.

At that point, we also thought that our next haul out would be back in Portugal in 2021 after the planned three years of exploring the Mediterranean Sea. Life however had other plans and not only we had to unexpectedly haul out in 2020 without having prepared for this upgrade, we only returned to Portugal in 2022 due to the Covid pandemic, one year later than planned.

During our unexpected haul out in 2020, we splashed a few more coats of the International antifoul paint, this time the new "recipe" called 350 Micron and postponed our ideas for the next haul out.

If the first antifoul paint lasted us three years the same could not be said for the second one which lasted maybe six months before we started having considerable growth on the hull.

The silver lining of these hiccups life dished us out was that it allowed us not only to do more research on the topic on the different options but also to meet other sailors with great experiences to share regarding Coppercoat that convinced us we were taking the right decision.

Early 2022 saw us crossing the entire Mediterranean Sea from Turkey to Portugal, where we had scheduled for haul out as part of our insurance requirements and of the final preparation stages for our Atlantic adventures. Portugal is a convenient place for us because we have a house and car we can use as a base instead of living onboard on the hard with Ella.

With the assistance of the Coppercoat team, we calculated how much product we would need to treat The Dream, a light displacement boat with a fat bum. They reckoned 15 kits would get us there but it would be better to go for 16 or 17 kits and be sure we weren’t skimping on the product.

We ordered the 18 kits while en route to Lisbon and by the time we got there and hauled out we were ready to start working.

The first big decision was how were we going to remove the old layers of antifoul paint?

Coppercoat requires a bare clean surface with no single-part paints applied.

There were three options on the table for that, each with significantly different costs, timings, advantages and disadvantages.

Sand or soda blast - this option gives results very fast but can set you back by 2500-3000€ and as we learned later it is recommended to leave the hull to dry (weeks if not months) after, as this process can push moisture into the hull fibreglass. It’s also very likely to remove all products including any barrier coat treatment done prior to applying the antifoul paint and even the gel coat. It’s quite an aggressive method very dependent on the skill level of the blasting machine operator.

Scrapper - this option is often used in older vessels that have had several coats of antifoul paint applied over the years and have a big build-up of old paint to be removed. It is reasonably fast, labour intensive but cheap and DIY friendly but after it is still necessary to sand and smooth out the grooves created by the tools used.

Sanding - this option is much slower to start seeing results and probably only recommended when there’s not much build-up of old layers to be removed but still very labour-intensive.

We decided to go for this last option, as it was within our level of skills and fitness. The price tag associated was not eye-watering and we had the idea that The Dream might have been treated with a barrier coat product while still in the factory during the commissioning period by the first owner. If that was the case we wanted to ensure minimal impact on that treatment.

The process was long and challenging. You can read and see details on the progress at the

Coppercoat antifoul treatment - preparation and application (part 2) . (coming up post)

At the same time as we were removing the old antifoul, we needed to make a decision regarding the waterline level.

We had always felt the waterline level was a bit low on The Dream, and when sailing the stern sits lower in the water as the boat lifts which meant a persistent growth above the waterline, more evident on the stern.

Add to this all the stuff we carry as liveaboards like extensive tool sets, extensive long-term provisions and toys and The Dream was definitely sitting a bit lower on the waterline level than desired.

With all that in mind, we decided to raise the waterline by 100mm from the bow to the midship and then carry that level in relation to the boot stripe all the way to the stern. This meant not only we needed to sand the gel coat in that area but we needed also to apply a barrier coat treatment prior to the Coppercoat application.

During the removal of the old antifoul, we identified a set of layers under the antifoul primer consistent with a barrier coat product. With the help of the Coppercoat team, we identified it as probably being a popular barrier coat option called Gelshield (consisting of alternate layers of green a greyish paint).

The important thing to confirm was if it was a two-part epoxy product or not because the epoxy used on the Coppercoat concoction reacts and doesn’t bond to single-part products. The test to confirm this was very simple and straightforward, we needed to wipe a sanded area clean and then using a clean rag wipe Acetone on the surface, hopefully, the rag would come clean without any traces of product or colour.

This was indeed the case, The Dream had been treated with a two-part epoxy barrier coat system and that was the layer we needed to get to while removing the old antifoul paint.

Part of the recommendations by the Coppercoat team was that the keel and bulb should be treated with a barrier coat generously to ensure that the integrity of their construction materials (iron) would be kept no matter what.

In our specific case that the entire hull, rudder and keel had already been prepared that way, they recommended reinforcing that treatment on the keel and bulb given we already had the paint in hand because of the raising of the waterline. We decided to go for what was probably overkill and applied six new coats of Gelshield to the original Gelshield treatment (the keel probably now has ten to twelve coats of barrier coat paint). We also gave four more coats of Gelshield on the rudder.

Hull showing the several different coats of the Gelshield barrier coat scheme (alternating coats of green and grey) applied to the waterline, seacocks, rudder and keel

During our discussions with the Coppercoat team, we queried if it was possible to treat the Truedesign (composite material) seacocks with Coppercoat. We had read somewhere at the time of the seacocks upgrade that some people had some success doing it. Their response was they had not tested themselves but couldn’t see why it wouldn’t work provided the correct preparation of the surface was achieved. Their suggestion was to abrade the seacocks surface and apply a few coats of the barrier coat to improve the bonding of the Coppercoat treatment. We followed their suggestion and used 120-grit paper to abrade the material before applying four coats of Gelshiled.

During our study of all the instructions and tutorials by Coppercoat, we came across the specifications to apply the product on aluminium and steel boats. With the saildrive in mind, we reached out to the Coppercoat team again and discussed the topic, once again with the right preparation the saildrive could be also treated. Light abrasion to the saildrive leg and several coats (five) of the correct primer (we used a specific primer from International called Interprotect). Another light abrasion of the primer and the Coppercoat could be applied, avoiding the raw water intakes and making sure the Coppercoat and anodes would not be in contact. We allowed a 1cm gap between the Coppercoat and the anodes but still treated this area with the Interprotect primer from International.

A 1cm gap is left between the applied Coppercoat and the anodes (seen in this photo in white)

We also took similar steps regarding the rudder top and the rudder stock, applying the same primer as we had done on the saildrive.

It was a long process taking weeks and physically challenging but all the preparation works were completed and the Coppercoat was applied.

Our application process was slightly different to what’s usually done because The Dream had to be moved when we finished sanding the hull we took the opportunity to start with the small areas where the handstands would be placed at the spot in the yard. Treating these small areas first allowed us to get a gauge of the challenges of mixing and applying the product as per the instructions. Although the mixed product is applied with a roller similar to normal paint, the viscosity and the behaviour are quite different.

One is supposed to apply light coats and repeat as they get tacky until achieving five coats, however, each coat has to be done in one continuous process, it is impossible to come back and do a touch-up if you feel it wasn’t quite right because if you do a second pass with the roller it removes product instead of putting more product on.

It requires a bit of self-discipline. On the other hand, the copper in suspension on the epoxy tends to sit on the tray with time but mixing constantly also ruins the mixture so once again it requires some self-discipline and a close eye on the signs that indicate copper is starting to drop so you give a good stir in the right moment without overdoing it, to add to this you have a very limited working time with the product and all mixed product must be used within 30-40 minutes.

This experience was in our opinion quite valuable, with the assistance of a precision scale, measuring cups and syringes we learned how to prepare small batches while keeping the right proportions and also determining the surface area each batch needs to cover regardless of the number of coats. When it came the time to treat the entire hull we simply opted to divide it into 3.5sqm areas and apply a full kit to each area (each kit treats 4 sqm) and proceeded at a pace we could control.

We ended up using only 16 of the 18 kits purchased!

With the full hull treated and curing the next step was sanding to activate the Coppercoat before returning The Dream to the water. If we were already slightly worried about making sure we had followed all instructions correctly now the worry was whether were we sanding enough or not enough. This is something quite difficult to give advice over email or telephone so we decided on the cautious side and do a very light abrasion only, Coppercoat team had commented that from their experiences a boat splashed on this side of the Atlantic tended to need less sanding than in the Caribbean because usually there wasn’t a problem with a slow patina formation. Plus with the help of a hookah system or some dive gear, we could always go back and abrade the hull a bit more whilst in the water.

Coppercoat slightly abraded with 400-grit paper after the curing period and before the boat is returned to the water

As the days scheduled for the treatment of the base of the keel and subsequent splash approached some nervousness also followed. This had been a reasonably expensive upgrade if it turned out to be a failure, but if we had done all correctly we believe we could actually be cost-neutral on maintenance within a few years between this specialist product and the standard antifoul options.

During the period we were working on this upgrade we kept a detailed spreadsheet of all costs to be able to get a real cost. The project done by us cost 4200€.

Before we had set our minds on a DIY application we had asked for several quotes to get an idea of how much this would cost us, prices had come up at around 8000€ depending on where in the Mediterranean region (labour cost was the factor for price differences), consumables not included based upon 2 quotes.

We know that a DIY normal antifoul application in the same yard cost us around 900€ and should get us through a year or two.

A pure cost analysis not factoring inflation over a period of 10 years (quite a common lifespan of the Coppercoat) puts normal antifoul paint at a price of 4500€ against the 4200€ of the Coppercoat application we made.

If we are as well succeeded as some friends of ours The Dream will not be coming out of the water for the next 10 years!

***The Dream is not affiliated or sponsored by Coppercoat or by Aquarius Marine Coatings Ltd, this blog post is based solely on our experiences with the product.

***You can find other posts of this series at Coppercoat antifoul treatment - preparation and application (part 2)

***In the spirit of sharing our dreams and experiences we have shared this blog post in the NOFOREIGNLAND.COM website sailors community.



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