AlastairW 15 Posted May 5, 2022 Share Posted May 5, 2022 3 hours ago, wheels said: I have discussed the Hemples silicon based AF in the past, but a bit too early for most, as it was once only available for Commercial applications here in NZ. As in, it was only imported in 44Gal drums and went direct to shipyards. It's great to see that has changed and is now available to the average boater. As said above, it does not have Biocides in it. But the development came about for two reasons. Firstly for commercial, TBT was being phased out. Secondly, the Copper based AF's have had many of their ingrediants phased out from use and the performance of Copper Based is becoming poor. Thirdly, People are becoming much more aware of what we are putting into our environment these days. So for any Company that advertises they have a safer alternative, then they obviously will gain an edge in market share with their product. As also said above, the slippery coatings DO NOT stop growth. But then, non of the Copper based Coating were doing that anyway. The only product that ever maintained a completely clean surface was the very expensive self eroding coatings that contain Hydrogen Peroxide. But they only last 12months. The only down side of the Silicon coatings is that they do need a resonably fast hull for self cleaning. I think minimum was 12kts. That's is far above most Hulls. But they are easy to brush down. The coating should last 5yrs because that is what they were designed for on Commerical Vessels. Commercial Vessels have to go through Survey every 5yrs. A Commerical owner does not want to have to haul out any sooner due to cost. On a Sailing Hull, there should be no reason what you cannot get 5yrs. If you were one that used the very first kind of non commercial products on the market, then you might not get 5yrs. Don't let that put you off on what is now available. The performance is improving all the time. After all, they are a very new and still developing product. These products work in a similar way to Prop speed etc. They are still only available for commercial application due to 2 reasons. The product is sprayed on with a commercial pressure sprayer. Because it is silicon, that pressure applicator needs to be used for that product only. Anyone that uses these silicon products and then tries to spray a normal Paint coating on a Boat is going to be in for a big surprise. No matter how well they cleaned the equipment. The same goes for keeping any possible overspray from floating arund in the air. A microscopic spec of silicon on another surface is a nightmare when it comes to painting. Even the materials and equipment used on preparation of the Hull before recoat needs to be kept separate from normal paint handling areas. Or at least, it is wise to anyway. The only downside I see to it is the cost. It might be OK when viewed over 5yrs, but it's a big chunk to have to find every 5yrs. Most of that is pretty accurate Wheels, we're looking to get somewhere around 10 years out of the product we use, at least that's what the US manufacturer quotes in their literature, and I expect they would get their backsides sued off over there if it wasn't the case, and they've been in business with this product for some time. Minimum speeds are now lower too, thankfully. There's not a hope that we could ever get our boat up to 12 knots. Some products will now start stripping at about 6 knots. When we were looking at what to use to replace the original soft coating, I came across one product (from International I think), that started stripping at less than 5 knots. As you say though, trouble is that you can't get most of the really good stuff in yacht sized quantities, even if you can get it in the NZ marketplace. Can't say what the requirements are for other products, but all of the prep work and coatings for Seaspeed are just what you would do for any underwater surface, nothing special used. Only the silicone coating needs dedicated equipment - no special sprayer or anything, normal diaphragm sprayer works well, but it IS silicone..... Quote Link to post Share on other sites
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