Experience with fouling release systems

This article actually talks about coatings that protect not only ships bottoms from fouling, but everything outside, from facades and terraces to garden devices. If you are not a sailor, this can also be interesting. The good thing is that the boat’s bottom is about the most potential place to let foul grow on, and it is the most important place to keep flat, smooth and clean. So it is the ideal thing to test if you can keep a surface clean, such as your terrace, your wooden garden chairs or the walls of your house.

So here you find the test results on the Ya.

History and future

For thousand years, as long as sailboats exist, we had foul on our bottoms and we scraped it off. Then the so called anti fouling paint came. You paint it under your boat once a year, in about 3-4 hours. It costs you for a 10 meter boat about 200 or 300 Euro, and if you let someone do it, about 400 Euro. This is a soaping paint, that contains biocides.

What is a biocide? Well, bio means life, cide means kill. It leaves that many killing components in the water. So the living creatures get poisoned, such as plants, barnicles, algues, it kills water plants and leaves the fishes with misforms and makes them die. 

The anti foulings build up in the water and this is worse and worse for nature. So the regulations get stronger. In the meanwhile the stuff is so weak that it works poorly. And still it leaves biocides to the nature. So there is no future for this sort.

It also costs pretty much money to get it off. Only a professional is allowed to spray it off with a pressure water hose, and all this water must be caught in a special sewer, to prevent this biocide would go into a sewer or in nature.

So more and more it is time for alternatives, the fouling release systems. These coatings are made so flat, that foulings can hardly grow on it. And if so, they should easily be cleaned off the surface.

Neosil and Biocoat

Under the Ya two fouling release systems have been put:

Neosil is a coating that only a professional can spray on your boat. First a special primer is sprayed and then the topcoat, that consists of a very smooth layer, probably with silicon and/or Teflon in it. That stuff makes it hard for the foul to grow and stick on.

Neosil is sprayed on the grey primer here.

Biocoat is a nanotech product, so extremely thin, that the surface should be really smooth in the first place. Here one also must know how to use the system. In contrary of Neosil, Bionics can be easily used on other stuff, like wood, or stone. (such as your garden wall). The fouling can not stick on it, because the coating structure itself is too dense, as hard as steel, and very flat.

Cleaning restrictions

Neosil and Biocoat can not be cleaned with a high pressure water syringe. It would damage the coat. But further, the coatings are strong. Compare it with steel. Don’t use steel, stone, nor sanding paper or sanding (steel)wool. Do use plastic scrapers, plastic brushes, whatever.

Biocoat also doesn’t like stronger acids.

Cleaning a 3 months fouling from the bottom

Here we show pictures of the cleaning from the Biocoat system. Actually we did not notice much difference with cleaning the Neosil, so the cleaning work on both systems are the same.

The foul grows wherever there is sunlight. So on the bows, standing vertical in the water, the fouling is well represented and tougher to get off.
On the bottom astern, where the sun hardly shines, there is hardly any fouling; you just see some yellow-grey dots.
A 3 month fouling is easy to get off. This broom wide part costs one minute work.
On the aft ship it was even easier. The left side on the picture was done in two minutes.

The complete bottom we cleaned in about an hour.

Cleaning the bottom after 10 months

We left the Ya in the water from September to July. We had a spring with great weather and lots of sun. So that helped the foul to grow. The sun came in especially on the foreship on the port side.

Here again, we show pictures of cleaning it from the Biocoat system, but cleaning it from Neosil is actually the same.

On port and starboard the fouling has grown heavily and it turned he bottom green black.
The white spots show some forming of barnacles. This was easy to scrape off (what we already did on the right).
First we started scraping with a plastic window scraper. Sometimes we sharpened it with a rough sanding paper on a plank. That helped. It takes 1 ½ manhour.
 Then we scrubbed it with a hard haired broom. This costs about 2 manhours work.
The top 15 cm we cleaned with a cloth to get the red colour back. That takes about an hour. Or more, if you want to clean it deeper to the bottom.
Although Inge was not happy with this result, I found the bottom flat enough. This picture shows the worst side, the port foreship, because there the sun ‘baked’ on it for 10 months and helped the fouling growing strong on the skin.
The more to the aft en the lower on the bottom, the less fouling and the easier it was to brush off.

Conclusion : the flatter, the better

Starting with a remarkable note: on the aft under the ship the Ya has a stainless steel heat exchanger. There the fouling was really easy to get off. Why? I think because the stainless steel is really flat. The Dijkstra’s are great sprayers and always deliver first class painting work, but however, a peace of polished stainless steel is simply smoother than paint.

Therefore, it perhaps could help if you first sand or even polish the paint before you put the Biocoat on it.

For the Neosil, I think it also can help if you polish it, let’ s say once a year.

If we compare it to the current anti fouling, some notes can be made:

  • A fouling release system like Biocoat or Neosil costs you some 3000 Euros on a 10 meter ship, done by a professional. Then it lasts long, at least 10 years. An antifouling each year costs you about 50 Euros to clean it, and 400 Euros to put it on your bottom. So the fouling release system is cheaper.
  • If you take your keelboat out of the water each season, you have to spend some 2, perhaps 3 manhours to clean the fouling off. If you are in the tropics, you have to do it anyway every 2 or 3 months for an hour or more, no matter if it is antifouling or a fouling release system.
  • The ethic thing: if you stop putting antifouling under your bottom, you live sustainable, because you stop compromising the future nature for the next generations.
In the tropics it is not a bad job to scrape the bottom. It gives a nice result, and some exercise is good for your health. Or, at least, if you have a fouling release system under your ship, and not a biocide.