This is such a difficult blog for me to write.  As you know, we spent a lot of money and time applying Coppercoat antifoul (see Coppercoat blog posts part I and part II) to our boat.  We had very high expectations that this product would last a very long time, save us money, and prevent us from hauling out every other year.  Maybe that was the problem?  Our expectations were too high?

The Prologue

We splashed from Norsand Boatyard and went up river to a marina. We stayed at the dock for 5 weeks and when we left, we had no concerns regarding the bottom job.  Why do you ask?

Last season we stayed in the same river for 8 months.  We had lots and lots of soft growth on our Carboline ablative paint.  I mean it looked like a small forest.  However, it easily fell off as soon as the boat started moving.  In fact, we sailed to Great Barrier (35-40nm) and by the time we got there the bottom had no growth!  Cool!

The Difference Between Seasons

As you might recall, last season 2023, had a lot of rain!  It rained at least 4 days a week if not more during the 8 months we were there!  Since we were on a river, the rain would fill the mountains and waterfalls which would push a lot of fresh, cold water down our river.  

However, this season we had very little rain and hot days.  Making the brackish water very warm and stagnant. Evidently this is a breeding ground for barnacles.

The Problem

Matt jumped in the water once we got to our first anchorage. He was completely shocked as our bottom was covered in barnacles.  This just 5 weeks after splashing into the water with fresh Coppercoat.

The barnacles were everywhere on the Coppercoat, on the hulls, on the stern, the bow, the very bottom and the daggerboards.  It was crushing!

Our Experiment

As you might recall, we did a little experiment.  We placed 4 different products on the bottom of our boat to see which would perform better over time.

As a note, Coppercoat cannot be near aluminum so we had to put a different product around the rudder shaft and the sail drive.

1. Coppercoat on the entire hull
2. Propspeed on the props.  This product can only go on the props, not on the hulls
3. Vivid antifoul bottom paint near the rudder shaft (black circle)
4. Vinyl Antifoul wrap near the sail drive (black square)

What was the outcome after the first 5 weeks?

The yellow propspeed had zero growth.  No soft or hard growth.  It was super clean!

The Vinyl antifoul, which we applied as sort of a joke, as we thought this would be the first to disintegrate or fall apart.  But this only had some soft growth which fell off with a light touch of your finger.

Vivid antifoul paint was covered in barnacles. 

And the Coppercoat was covered.

What Did we Do?

For those of you who know me this will come as no surprise.  I sent videos and photos to the marina (just to give them a heads up), to the yard (again a heads up and sought advice), and to the manufacturer of Coppercoat.

There are 5-6 marinas on this same river.  We know of several boats, that stayed at various marinas on this river that had similar problems. Some had antifoul paint and some Coppercoat – all the same results with tons of barnacles.

After a lot of back and forth, the manufacturer did nothing other than provide some insights.  I thought I’d share them here with the hopes that it would be helpful for other cruisers who have Coppercoat.

Insights

Assuming the Coppercoat was applied correctly, which we believe it was (again refer to our Coppercoat blog posts part I and part II)  and compare the application process to that which is recommended by Coppercoat).  

• Standard antifoul paint starts off at full strength (containing the maximum biocide content when new) and gradually wears down (it grows weaker as the biocides leach away). Making is less effective the older it becomes (which we have seen first hand).  
• Coppercoat when freshly applied is a relatively mild antifoul. It becomes stronger week by week.   Commonly, a two-year old treatment performs better than a two-week old treatment. This is because it takes time for the epoxy at the outer surface of the treatment to break down and allow the release of the copper.  This would have been good to know BEFORE we applied the Coppercoat as we may have changed our plans after launch.
• Pure copper itself is relatively mild antifoul agent. It is actually the by-product of the copper oxidization process that have the stronger qualities.  Cuprous oxide is a far more powerful antifoul than pure copper.  It is the double effect of the resin degrading (to allow the exposure and release of the copper) itself oxidizing, that combine to provide a highly efficient antifoul.  And this process takes time.

Although we are very confident in the correct application process done by the yard, I failed to note what grade of sandpaper was used on the last burnishing.  I just noted in our blog that they sanded which is what they need to do to activate the Coppercoat. I wish I would have checked the grade.  However, I find it a ridiculous notion that they yard, who has been applying  Coppercoat for 10 years would have used the incorrect grade after all the time and effort it took to get to the final stage.  If they used a course or low grade sandpaper (something below 300 grade), which we truly believe the did not, it could have added to the problem (not been the cause of the problem, but added to it).

Bad Timing?

So does this all add up to just bad timing?  Our resin did not have a chance to degrade so the copper did not oxidize which allowed the barnacles a free hold on our bottom.

And it appears our boat was launched during a particularly high fouling time in a high fouling area.

We are aware of several other boats that stayed at different marinas along the same river and they too had a seriously bad barnacle problem.  In fact, one boat had Coppercoat that was applied a year ago, another had Coppercoat applied 5 months ago, and one had ablative bottom paint. All were covered in barnacles.  So, it was not just our marina, but perhaps the river, the warm water temperature, and bad timing?

The Solution

We immediately started cleaning the bottom of the boat with a metal scraper (while she is still in the water).  It took us 4 days and several turns with the hooka (diving apparatus) to remove all of the barnacles.  Again, this just breaks my heart!  We had such high hopes!  The reason it took us several days was because the water temps are really cold (20-21C) 69-70F degrees.  So, even with a wet suit we could not stay in the water more than 1.5-2hours at a time.

We unfortunately did not have the opportunity to haul the boat out immediately after discovery so we did the best we could with cleaning her while she was in the water.  You can see where we cleaned the top part in this photo.

We started with the metal scraper then followed it up with a scotch bright (mild) pad to get any remaining soft growth off the hull.

All in all it took us a total of 9 hours to clean the boat.  That’s 9 hours in 21c (69F) water which is really damn cold even in our wetsuits!

The good news is that 90% of the barnacles came off relatively easy with the metal scrape.  About 10% required more attention to get their white base off.  It was really difficult to get them off the freezer plates, SSB plates and around the dagger board casing.

Manufacturer Solution:

• A thorough cleaning should be done immediately (and was).
• The preferred method would be to haul the boat out and pressure wash it.  Then use a metal scraper (the type to decorate or remove old wall paper) to scrape off any remaining barnacles.  A fine grade of wet-and-dry paper (320 grade) should then be used.
  • The purpose of the sand paper is to remove the thinnest layer of epoxy at the surface to expose the copper held within. The exposed copper with then oxidize more readily when the boat is re-launched
• Using course sandpaper will simply scratch the surface and provide a physical key for marine life to try to cling to. Only use mild grade paper or a burnishing pad.
• It is important to do this quickly, before the growth becomes worse and attaches more firmly, as that will only make the cleaning more difficult.

After more back and forth, Aquarius Marine (Coppercoat UK), HullWell, and Norsand agreed to cover the cost to remove any remaining barnacles, and fully machine burnish the bottom at our next haul out.  We will be responsible for the cost to haul the boat and pressure wash it.  We will schedule to haul the boat out at the end of April as close to our departure date as possible – with the hopes of leaving NZ with a clean hull.

Still Hopeful

Matt and I are NOT giving up hope on Coppercoat.  We are hopeful that we were just at the wrong place at the wrong time with very young Coppercoat that was not ready for an onslaught of barnacles. So, I would say “not an overall failure but a complete and total disappointment.”

We will keep you posted on our experiment.  Feel free to contact us with any questions.

Our blog posts usually run 10-12 weeks behind actual live events, but I wanted this post to go out fairly close to the other two Coppercoat posts.  We discovered the barnacles around the end of January.  We are in a sticky situation in our last blog – did you read why?