Some good commentary
I will append some information from a boat builder acquaintance with over 30 years building & repairing FRP and composite hulls. I had forwarded the thread to see if he had some commentary.
His remarks are thoughtful, and based on my knowledge of his background, very well-informed.
Hi Loren,
Copper coating has been around for a long time and has been modified over the years. Looking at the photos in the thread it looks to go on smoother then the original in its current form.
The issue that someone has with it flaking off is interesting and I would assume it is being caused by one of several possibilities. The surface was still contaminated from the soda blasting or contaminated by some other sanding/degreasing or? The product application was started early in the morning and there was some dampness on the surface or perhaps there was so much salt driven into the surface over the years that it was damp. The product could have been applied on a really hot day and the tack between coats was missed. I could go on but you get the idea, it could be something like just not enough product on the hull. We had a similar problem once with a Vinylester product because after application the customer sanded the hull fair and then did not apply more product so that in some areas it was real thin. The product got small pin blisters in the thin areas.
Now the real problem or should I say lack of performance issue. Put your logic cap on, if the copper is in an epoxy resin then all the particles are coated and it will take a light sanding to expose copper to do its job. The small amount of copper exposed will need to be lightly sanded from time to time to expose fresh copper and so on. In fresh water the slime will still grow because the silt in the water gets trapped on the surface and the slime grows on it just as it does on the bottom paint. So you will still need to scrub the bottom to keep it clean.
A side effect of a bottom finish that the customer thinks doesn’t need to be hauled out on a regular basses is that things like thru hulls, zincs and bearings get looked at less which is one of the reason we haul our boats.
It is interesting to me that Trinidad works so well and in fact we do test other paints (usually on one of our employees boats) one of which was being touted as a competitive to Trinidad and when we just hauled it last week there was a small growth on to hidden (sp) in the slime that would not pressure wash off and in fact required vigorous scrubbing with scotch bright to remove. We won’t be recommending that paint to our customers.
I just don’t think there is any golden bullet out there. I use VC17 of Pettit SR21 on both my 70 and my cal 20, do I need to scrub it? Yes but everything comes off easily just as it does on Trinidad.
Enjoy the hunt,
S____