Who has added copper powder to bottom paint, did it work ?

[David M]

Originally Posted by fstbttms

It doesn't work at all. Look, anti fouling paints are a complex mix of solvents, binders, pigments and biocides that the manufacturers have spent decades and hundreds of millions of dollars developing. It is unrealistic to think that you can simply grind up some copper pipe or a handful of pennies or something, toss it in the can and expect that your kitchen sink chemistry experiment is going to increase the paint's effectiveness. And despite what some boaters may claim anecdotally, there is ZERO evidence or data to the contrary. Not to mention that modifying your expensive bottom paint in this manner is absolutely going to void any warranty it might have come with.

Backyard chemists are not going to be more knowledgable than the people who have spent decades competing against each other formulating concoctions to keep stuff from growing on hulls. If copper powder was better it would have been added many years ago.

[catsketcher]

I have two friends here on the lake who have made their own copper epoxy bottom coating.

They both did the same process. Lots of copper flakes mixed in with a 105 equivalent resin. It is hard to get the copper to stay in suspension so small batches have to be done. I worked out it would cost me about $500 in copper to do my boat plus the epoxy. I was tempted but couldn't find the time to strip my antifoul back to primer for the epoxy. Another cat owner here is going to do it soon, as we have some hassles finding places to slip our cats and work on them too.

Both owners are happy with their choice. One has had his boat in the water for 12 years (Schionning 1320) and the other did their Seawind 1000 about 3 years ago.

Basically you still have to swim on your boat, but cats are easy to swim on and any growth comes off really easily. One friends uses a 300mm wide gyprock trowel to carve all growth off. Takes him a short time.

A sand every now and then is helpful too to take the top surface of the coating off and expose new copper. Neither owner minds doing it, they feel that they save money by not slipping every year, have an extra barrier against penetration and can get a really nice and smooth hull finish with a quick sand.

Another friend has copper expoxy on his racing livaboard cat. I think he made it himself too. It really is not too hard, just mix in the maximum amount of copper powder into epoxy and roll it on, do a few coats and then sand before launching.

Although there are widely differing stories on the internet, a home made finish can work if you don't mind donning goggles every 8 weeks or so, to keep the hull super smooth. Even with my antifoul, I have to clean it three times a year, about every 4 months to keep it super smooth.

All that being said, I saw another cat on the slips on the weekend - it had copper epoxy on it and I guess it was getting some bottom paint on it. The owner did his own epoxy bottom 20 years ago and may have gotten over needing to swim every 8 weeks.

[lateral]

Originally Posted by fstbttms

I don't know where you do your boating but there are places where house paint will perform as well as what you just described. One year and then your DIY version of Coppercoat was replaced with something else? Sounds like a resounding success.

I guess if you only considering lack of growth, success, then TBT would still be available.
Some are trying to lessen their impact on the environment with
manmade chemical crap entering the marine food chain with their endeavours.
If with extra elbow grease and activators to the copper this can be achieved
I applaud them.

[fstbttms]

Originally Posted by lateral

I guess if you only considering lack of growth, success, then TBT would still be available.
Some are trying to lessen their impact on the environment with
manmade chemical crap entering the marine food chain with their endeavours.
If with extra elbow grease and activators to the copper this can be achieved
I applaud them.

I do not consider lack of growth the only criteria for a successful anti fouling paint. But I do understand that reasonable anti fouling performance is necessary in the places where moderate-to-high fouling is a reality. And until something is developed that can do a relatively good job of it without a biocide, copper-based anti fouling paints are the current choice. Anybody who thinks that non-copper coatings or low-leaching copper-loaded epoxies (like Coppercoat) can achieve anything approaching "reasonable" anti fouling performance has never maintained them where I do.