Copperbottom ... time to Antifoul?

[Jonny_H]

We bought our boat just before xmas and in all the excitement forgot to give the copperbottom a rub down before she was launched in March. Needless to say we now have a weedy bottom /forums/images/graemlins/blush.gif

The stuff on the waterline isn't very bad (a gave it a scrub this summer) but when moored up in clear water the rudder shows quite a lot of growth.

The copperbottom is now 11 years old. Next year we are setting off for an 18 month trip to Australia in her, so would like the bottom to be weed free!

Should I just make sure the copperbottom is given a good scouring pre-launch next season, or is it time to give up and give her a few coats of antifouling this winter?

If I decide on the latter course - I presume I can just antifoul straight over the copperbottom (after a quick sand to key the surface and remove any loose particles) as it is essentially just an epoxy coating /forums/images/graemlins/confused.gif

Jonny

 

[Sans Bateau]

We have Coppercoat on our boat.

We too get weed growing where a lot of light can stimulate its growth, that is, the rudder and at the bow of the boat where the water is shallow. We do not get any crustacous growth at all!

I understand that weed and slim will grow on this type of antifoul because it does not contain the chemical contained in regular antifoul to stop this. To address this, this year I have used Blakes on the rudder and the first metre of the underwater section at the bow.

I have found that abrading the coppercoat very hard going, it is a very hard surface! If the underside of the boat looks green after you have washed off the weed and slim, then its working. I understand it is the copper oxide that stops the barnacles.

If you antifoul with regular paint, you will need to clean off all the oxide and then use a primer.

Question you have to ask yourself is, will the clearer waters you will be sailing in promote more growth of weed, or will a boat that spends more time underway not get a chance to grow weed? Then ask yourself, what is going to be easier, reantifouling or just giving her a scrub.

 

[snowleopard]

I relied on Coppercoat for a season in the Caribbean. It was next to useless in tropical waters with a thick layer of calcareous growth after a few weeks. Next time I go I plan to put a few coats of eroding a/f over it before I go. I found that boatyards out there were still using TBT in 2002 so I'd go for that if you can still get it.

As long as you use eroding a/f it should gradually disappear so you'll be back to the copper in time, i.e. when you get back into cooler water (and the water in NSW is certainly cool!)

 

[Jonny_H]

Thanks - yes the bottom does look green where there is no weed - so assume its working. As you say no crustations - just slimy weed.

I think our copper stuff is Copperbott 2000 - but assume they all perform broadly the same. If they're not very good in tropical waters then I think I'll antifoul her this winter whilst she's out.

What sort of surface prep will I need to do before I can antifoul - does it needs lots of rubbing down? I assume that if I antifoul then when the antifouling erodes it will come back to the coppercoat which will be better than nothing at keeping the weed off. With this in mind is eroding a/f better than the hard stuff?

Jonny

 

[orizaba]

i was about to post a similar question.
my coppercoat was fine in cardiff had her out after 2 + years in the water ,just a layer of slime,easily washed of,then over to portugal for 1 yr dried out in sines,i wasn't able to get all the slime off due to time constraints nor polish it up as i'd hoped,we went into the med and i can see weed growing at speed, "almost weed on speed" i've just got a stiff broom and some scouring pads and am going to see how much i can clean off/polish. the water line+300mm or so is conventionly anti fouled using flags anti foul and that seems fairly ok not too much if any growth, more investigation later today
to be honest i'm not sure whether the problem stems from not enough copper exposed or very aggressive weed/barnacles.
i see there have been a few comment regarding the carribean, my experience of it says that its fine in colder waters,not sure in warmer/clearer
as for putting conventional anti foul over coppercoat as far as i remember i just put it straight on,that was over 4 years ago and it all stayed on.

my questions are,,
doesyour coppercoat work in warmer/clearer waters even when well polished or do i have to bite the bullet and conventionally antifoul over the top.
if i do have to antifoul it what make of anti foul would you use,my thoughts are to use what the locals use,hempels seems to be popular .
what are you using and does it work in the med

 

[adl]

I assisted in the reapplication to coppercoat to a Oyster 55 which has completed a circumnavigation through the carribbian and pacific, the skipper reckoned the stuff in the tropics was fine, maybe you need to make sure you have enough copper exposed using a green kitchen cleaning thing.

Incidently I have applied CC to my Westerly 38 2 seasons ago, apart from having the bottom jetwashed once a season in cowes I am only getting minimal green slime at the waterline.

 

[Jonny_H]

I have no doubt it would be ok if it was recently applied, but I believe the manufacturers quote around 10 years of service, mine has been on for 11 years now, so maybe its getting past its best and antifouling seems lots easier than re applying coppercoat?

 

[Sans Bateau]

The application of copper based antifoul is all important. Both my friend with his Hanse 371 and myself have Coppercoat. Both boats are in the same marina in Chi Harbour.

Hanse 371: professional spray application, curred with heated lamps undercover. - Poor performance, lots of weed.

Same Hanse, strip at water line to extend height and keel re coated after repair, both done outside in boarderline conditions - both areas working well.

ETAP 35i: applied by us, outside well within climatic limits - works OK no crustacous growth but some weed and slime.

What we have concluded is that the 'professional' application with heated lamps has cured the epoxy to hard. Our own boat where the epoxy also cured well is difficult to abrade, its too hard.

THe Hanse 371, where the coating was applied in boarderline conditions, the epoxy is softer and can be abraded. The keel on the Hanse was completely clear of any growth when she was scrubbed early this month.

So to summarise, the harder the epoxy the poorer the performance. DIY application is better than pro, but dont do it mid summer, its too hot! Apply just within the climatic limits. All other application criteria must be adhered to, IE clean dry hull free of ALL old antifoul, degrease etc and the epoxy/copper/curring agent mixed well using a mechanical means.

 

[adl]

I concure I painstainkinly took 8 weekends with fiends to scrape back to gelcoat 8 years of AF. The hull was washed down, abraided and then washed down again. I think it was a warm febuary weekend in 2006 when we went down taped the waterline off and commenced the mixing and application of the product, it took all day and as has been said above temp and humidity need to be as per instruction.

Having talked to the south african chap who runs the floating scrubbing dock in cowes it is apparent that very poorly applied cc is doomed to fail from the out.

You points about a cured epoxy under heating are valid and obvious. I am sure you could lightly abrade with some mechanical machine if required. Just wear the correct PPE!

 

[pmyatt]

Surely, for antifouling purposes, you shouldn't need to replace or cover the Coppercoat until such time as you have abraded away all remnants of the green copper oxide.

 

[sportsfisher]

Hi Johny H,

Just a couple of points.

I have had a boat with coppercoat on it. It (the coppercoat and the boat!) was a few years old when i bought it. When it was about 8 yrs old I decieded it needed re-doing. I spoke to coppercoat and they told me I could abade it and paint on normal antifoul or more coppercoat no problem. I was on a tidal mooring and I dried out on roughish ground so as normal antifoul wouldn't last a month I went with coppercoat again.

Having searched around at the time, i looked at coppercoat, copperbot 2000, etc and all the alternatives (btw dont think you can have had copperbot 2000 as it only came out in 2000!), I went with coppercoat as it had worked for 8 yrs no probs and the alternatives weren't cheap enough for me to risk it.

How come you are thinking about going back to normal antifoul if it worked for you for 11 yrs?

Hope the above is of interest.

 

[Jonny_H]

Hi - we only the bought the boat 10 months ago. She is now in her 11 year in comission, (lifted out each winter) but was coppercoated when new.
I assumed it was Copperbot 2000 as the previous owner left a small kit of this in the cockpit locker which he used to 'touch in' areas which had thinned each winter. It may well be different copper bottom, and he just used copperbot 2000 to touch in the bits that needed it.

I assume it has worked fine for 11 years (according to the prior owner), but this year we forgot to abraid it prior to launch and have had some growth. It may be that the lack of abraision is the problem - in which case I can abraid it next year and try again. However, if the problem is that the coppercoat has reached the end of its life I need to do something this winter as when she is launched next year it will be 2 years later in Australia when she is next lifted out! I could always re-coat copperbottom this winter, but it sounds much harder to apply than regular a/f, and more expensive - plus I didn't know how well it performed in tropical waters.

Hope that helps answer your questions.

Thanks for the input so far ... all very interesting, food for thought indeed!

Jonny