Antifouling!

[Hurricane]

Thanks M, good to know.
So, am I right in understanding that you don't need to go back to bare gelcoat, as long as the existing CC is made smooth?
What did you use for the job, an orbital sander I suppose? And which grit size?
Also, after sanding, can the fresh CC be applied directly, with no primer?
Last but not least, how many hands did you re-apply?
Great final result anyhow, very well done! :encouragement:

Yes - CC on top of the old CC works fine.
No need to go back to the gelcoat.
I bought a couple of cheap orbital sanders - making sure that they had the bigger orbit diameter (5mm)
These are the ones I bought:-
https://www.screwfix.eu/mac-allister-meos400-125mm-random-orbit-sander-240v.html
They need to be light enough to hold upside down and at the same time aggressive enough to do the job.
I bought some cheap 80 and 60 grit sandpaper discs which were a mistake - the loop on the back didn't last.
We also had some 120 grit 3M discs which worked better.
So, if I were doing it again, I would use 60 and 80 grit but buy a better make of disc.

Remember when sanding, you are sanding copper.
During sanding, we were looking for a smooth copper colour finish.
Believe me - it is hard work.

No primer but we used the CC thinners on all coats.
All the coats of CC need to be applied during one day - you can't let it dry - just wait long enough to get the next coat on.
The first coat looks as though nothing has gone on and dries reasonably quickly.
The second coat takes a lot longer before the third coat can be applied.
We only had time to do three extra coats even though we split the job in two halves - i.e. one side one day - the other side the next day.

We lifted the boat for a mid season wash and the CC looked great.
And whilst swimming with the boat last week it was very obvious that the CC was in good condition.

Hope that helps

 

[MapisM]

Hope that helps

Indeed - thanks a lot!
I am saving the link to this thread for future reference, when in some years (hopefully, at least 3 or 4) I will have to go through the same process.

Congratulations for doing the job yourself, anyhow. Having seen what it takes to pass orbital sander just on gelcoat (to get a perfect finishing after blasting the hull), I'll rather bite the bullet and pay my yard.
Btw, yards are normally equipped with professional orbital sanders, to which they can attach an aspiration hose.
That's how they worked when my boat was sheltered, and it was a very clean job.
I don't think it's very healthy to breathe air filled with the thin copper powder produced by sanding...
You used a mask at least, did you!?

 

[John100156]

I have not been out since it was lifted and only thought he was going to AF the hull, but noticed he had allowed to AF'd props and shafts too, when the images were taken; on the last three occaions with the F43 I had him use Trilux, I assumed he had done so this time, I'll let you know what he has used, you could very well be right so I can trial it again!

When lifted he and I agreed both Velox and Trilux had been previously used.

Boat now back on berth and all is well - using M350 and white Trilux on shafts and props...…