Advice on overcoating coppercoat please.

[DanTribe]

For some years patches of antifouling have been flaking off. I have been patching these in and painting over [ i.e. bodging]
This season I decided to completely strip the antifoul & start afresh.
Having stripped most of one side it appears that she has been coppercoated at some time before my ownership at least 15 years ago.
My original thought was to give a couple of coats of Gelshield then underwater undercoat before new antifoul. I'm now wondering if that's such a good idea. What would stick to coppercoat? Any advice gratefully considered.
Thanks
Dan

 

[youen]

I was not happy with my Coppercoat,I abraded it and then overcoated directly with International Micron and I had a good result

 

[Daydream believer]

I had copper coat that did not work. the manufacturer said it was my fault i had not applied it correctly. hence i over coated it
With copper coat !!
Jury still out on whether i have wasted my time again
there are lots of pros & cons as to coppercoat & the Op was not inquiring about that
however, On my last boat I had copper Bot, which failed, & i just painted straight over it with XM & that stuck Ok

 

[wotayottie]

I didnt think it had been around 15 years. But in any case it is an epoxy based coating but one that by now will be well and trully cured. I would abrade then apply and underwater primer before antifoul.

 

[macd]

I didnt think it had been around 15 years.

It has certainly been around for well over that, originally as Copperbot. The OP's problem, though, is that although he has presumably deduced that it is a metallic copper-based coating, he has no way of knowing whether it is actually Coppercoat. Unfortunately I can't think of any easy way of determining that one way or the other.

Either way, it would do no harm to ask the Coppercoat people, AMC. They're generally pretty helpful.

 

[Elessar]

For some years patches of antifouling have been flaking off. I have been patching these in and painting over [ i.e. bodging]
This season I decided to completely strip the antifoul & start afresh.
Having stripped most of one side it appears that she has been coppercoated at some time before my ownership at least 15 years ago.
My original thought was to give a couple of coats of Gelshield then underwater undercoat before new antifoul. I'm now wondering if that's such a good idea. What would stick to coppercoat? Any advice gratefully considered.
Thanks
Dan

Abrade thoroughly with 100 grit. Then any epoxy, including coppercoat, or a coat of antifoul primer followed by ordinary antifoul.

 

[EwanClark]

We launched the current formulation of Coppercoat back in 1997, so 18 years ago. But there have been several failed copy-cat versions come and go in the meantime, so the only way to be sure of what is on this hull is to check the boats paperwork file to see if there is an old sales invoice.

However, if you strip the hull of all the flaking paint coatings, so that you are back to a sound layer of copper-epoxy or gel-coat, you can then apply any system you fancy. Naturally I would recommend Coppercoat!!!

 

[Sticky Stuff]

Any antifouling sales organisation will have a good number of requests each year to over-coat Epoxy copper type systems.
This is not unusual and has been going on for as long as they have been around and for the foreseeable future this is unlikely to change.

If you are not happy with your antifouling at any point show your dissatisfaction and just change it, try another brand ..... this is a no extra work or extra cost option !
If you are not happy with your copper system just overcoat it ..... cost ???? You tell me ?

As they are Epoxy they can work well as a water barrier, don't remove it if it isn't peeling off, use it as a primer for your antifouling ..... ok ok expensive primer i know !

 

[Sticky Stuff]

Any Epoxy primer will stick to a well sanded epoxy copper layer
Gellshield 200
Hemple EPU
Jotun Antipest
Nautix PE

 

[oldsaltoz]

For some years patches of antifouling have been flaking off. I have been patching these in and painting over [ i.e. bodging]
This season I decided to completely strip the antifoul & start afresh.
Having stripped most of one side it appears that she has been coppercoated at some time before my ownership at least 15 years ago.
My original thought was to give a couple of coats of Gelshield then underwater undercoat before new antifoul. I'm now wondering if that's such a good idea. What would stick to coppercoat? Any advice gratefully considered.
Thanks
Dan

Copper coat is an epoxy based system, the reason you have the problem with bits flaking off is because almost nothing will stick to Epoxy, a bit like silicon.

You need to establish how high up the sides the epoxy was applied, sand it, apply and epoxy priomer and do what ever you like after that.

Good luck and fair winds.

 

[Birdseye]

epoxy will stick to abraded epoxy no problem. And if I remember right, Blakes suggest that you apply the first coat of conventional antifoul to an epoxy coated hull when the epoxy coating itself is still a bit tacky.

 

[DanTribe]

Thanks for all your replies, very reassuring.
I was suckered into starting this job because a few patches were flaking and when I tried, large areas stripped off easily. Of course, as I suspected, some areas have stuck like that stuff to a blanket so many hours of chip chip chip with a chisel awaits.
Much of the exposed hull is copper coloured and has a hard sheen, almost feels waxy. The areas that have resisted stripping are probably those that have been patch primed subsequently over years.
Because I cant guarantee having removed every bit of conventional paint I think I'll abandon the idea of putting more epoxy on. So I'll abrade with 100 and 2 coats underwater primer.
Boat ownership is good fun innit?

 

[oldsaltoz]

Because I cant guarantee having removed every bit of conventional paint I think I'll abandon the idea of putting more epoxy on. So I'll abrade with 100 and 2 coats underwater primer.
Boat ownership is good fun innit?

When you say Underwater Primer, I assume you mean a Primer to go over Epoxy.

Good luck and fair winds.

 

[Pasarell]

epoxy will stick to abraded epoxy no problem. And if I remember right, Blakes suggest that you apply the first coat of conventional antifoul to an epoxy coated hull when the epoxy coating itself is still a bit tacky.

That will be on a solvent free epoxy. If the epoxy is solvent based, and that includes water based, you will have a disaster on your hands.

 

[oldsaltoz]

epoxy will stick to abraded epoxy no problem. And if I remember right, Blakes suggest that you apply the first coat of conventional antifoul to an epoxy coated hull when the epoxy coating itself is still a bit tacky.

This sounds like a desperate measure to get something to stick to an epoxy that would not anomaly do so.

Applying ANY product over Epoxy that has not fully cured and been then abraded is madness and may even contaminate the lay-up.

Good luck and faire winds.

 

[RichardS]

That will be on a solvent free epoxy. If the epoxy is solvent based, and that includes water based, you will have a disaster on your hands.

That surprises me. I have always thought that "solvent" in this context and, indeed, most contexts, meant a volatile, petroleum-based or synthesised solvent.

I appreciate that water is also a solvent but is not usually called such in this context.

Richard

 

[Pasarell]

You're right, of course, that most coatings traditionally used a VOC solvent especially in industrial applications such as marine. It started to get confused 30 or so years ago as products were developed using water as the solvent and some people described them as solvent free. More accurately a coating should be described by its volume solids where solvent free would be 100 VS%. Solvent based coatings will have the solvent type described in its data sheet. Knowing the VS% is important when working out the film thickness to apply for effective protection.

 

[Iliade]

Thanks for all your replies, very reassuring.
I was suckered into starting this job because a few patches were flaking and when I tried, large areas stripped off easily. Of course, as I suspected, some areas have stuck like that stuff to a blanket so many hours of chip chip chip with a chisel awaits.
Much of the exposed hull is copper coloured and has a hard sheen, almost feels waxy. The areas that have resisted stripping are probably those that have been patch primed subsequently over years.
Because I cant guarantee having removed every bit of conventional paint I think I'll abandon the idea of putting more epoxy on. So I'll abrade with 100 and 2 coats underwater primer.
Boat ownership is good fun innit?

Coppercoat should be green, not copper coloured. I suspect that may be an epoxy used for osmosis treatment/protection.

If it is shiny copper coloured, try sanding it down a little then relaunch and see what grows!

 

[Elessar]

This sounds like a desperate measure to get something to stick to an epoxy that would not anomaly do so.

Applying ANY product over Epoxy that has not fully cured and been then abraded is madness and may even contaminate the lay-up.

Good luck and faire winds.

it isn't mad at all! Solvent free epoxy and solvented epoxy are completely different things, and people get the rules for them mixed up then treat them as gospel.

If you are using solvent free it has a 24 hour overcoat window and so you overpaint before cured. It is not desparate, it will not contaminate anything, it is correct!

 

[vyv_cox]

This sounds like a desperate measure to get something to stick to an epoxy that would not anomaly do so.

Applying ANY product over Epoxy that has not fully cured and been then abraded is madness and may even contaminate the lay-up.

The instructions with the Gelshield 200 that I applied over ten years ago specifically instructed me to apply a coat of hard scrubbable antifouling over the final coat of the product before it had cured. I forget the exact time but I seem to remember that it had to be less than 24 hours, while the last coat was tacky. The hard A/F acts as a tie coat enabling eroding A/F to be applied subsequently.

Current instructions don't seem to say that but they quote a minimum overcoating time of 3 hours at 23 C. Only after 6 months do they advise abrading.