Preparing the Hull

One of our summer project is switching to Coppercoat from traditional anti-fouling, and the first step was to remove all the old paint and barrier coating to prepare the hull for the new paint. 

From new, Linnea came with epoxi treatment under the anti-fouling, but since we had no idea if this had been damaged during the years, and we wanted to do some reinforcements infront of the keel, as well as raising the waterline, we decided to go all in and redo the epoxi treatment as well. This way, we know that we have good protection that will last for many, many years to come.  

Our best tips for
anti-fouling removal

1. Spend time finding a good paint scraper that actually works on your type of anti fouling. 

2. Spend your money on a pro sander – you want to be able to use your arms even after this.

 3. Do buy the more expensive sanding pads, it will be cheaper in the end.

Update Nov 13, 2021:

The epoxi treatment we did in 2020 failed due to a series of unknown events and had to be redone in 2021. This post about how we removed the old anti-fouling still applies and contains some good tips if you are to do this yourself. If you are doing an epoxi treatment, or just have a general curiosity for boat stuff, we really recommend that you read our summary about the epoxi failure and what we learned, described here.

Enjoy 🙂 

Scraping

The old paint was removed by hand force, using paint scrapers to scrape it all off. We started out with four different kinds of scrapers, some old and some new. It was a really tough job and about one hour in we were about to give up. No matter which scrapers we used, the paint just wouldn’t come off without using all our strength. It was tiring! 

We thought about different solutions, all from sanding it down with an orbital sander to finding someone that could help us blast it with sand. All which sounded like expensive solutions. But from before Marcus had a small Bacho scraper, not wider than 1 cm, that we tried mostly because we were running out of ideas. This little thing cut through the paint like butter! We were not really keen on scraping the entire hull using a 1 cm wide scraper but it turned out that this scraper also is made in a wider kind. And wow! What a difference it was compared to the scrapers we used before! If you are ever doing this on your own, try out the Bacho scrapers! All in all, it took about 3 working days for two persons to remove all the paint with two good scrapers. 

Important! 

As you scrape the anti-fouling off, make sure you collect all the residue into containers so that it does not end up in the nature. We did this by putting out tarpaulin under the boat and gather it all into garbage bags. Another suggestion is to use scrapers that can be connected to a vacuum cleaner. 

Sanding

Next up was to remove the last remains of the anti-fouling, and smooth the surface using the orbital sander. This procedure is also what is recommended as preparation for the barrier coat we are using.  From before we had a good industrial vacuum cleaner and a good light weight orbital sander with a 150 disk. At first we thought that we maybe should get a cheaper sander to do the most dirty work, so that we wouldn’t ruin the professional one with paint residual. We are glad we decided against it! Having a light weight sander, that shakes minimally, has really saved our arms, hands and backs during this project. 

The sander we have is from Mirka and we decided to also buy their special Abranet sanding pads. The pads are made out of a net structure that makes it easier for the vacuum cleaner to keep the pads from clogging, which really helped. We sanded the entire hull using the 80 grid  Abranet Ace HD pads, and it worked really well! These sanding pads are a bit more expensive than more traditional no-name pads, but from our experience we would say that this turned out cheaper anyway since we have not used nearly as many as we have heard other use doing the same job with cheaper pads. All in all, we only used 12 pads for the entire hull. Using 80 grid sanding paper is what’s recommended for our specific barrier coat. If you are doing any similar work we would really advise to check the manufacturer recommendations of your selected coating.  

What about the tricky areas? 

For the tricky, non-flat areas around the keel and in the bow thruster tunnel we actually used the same sanding pads. We used the pads that were too worn out to be used on the orbital sander and used them by hand instead. To get som extra force and pressure we cut off the handle of an old ore. Using the Abranet also for the hand sanding meant that we were able to cover large areas without having them clog up, you just had to shake them off a bit and then they were good to go again. 

Marcus prepared to sanding the hull

In the next post we will describe the reinforcements we have made. It will be glasfiber work, fairing and more sanding! You can read about it all here

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