Can Coppercoat increase speed?

Montemar

Well-Known Member
Joined
17 Jan 2011
Messages
832
Location
Dorset
www.voltloudspeakers.co.uk
If I strip off all the old anti foul and get Coppercoat applied can I expect a top speed increase?
If so I can then expect higher speed for as long as it continues to work which is some advantage over a few years worth of the normal stuff which gets rougher with each coat and increases drag.
Apart from that it would save a lot of effort every spring.
It is a rather expensive process especially the hull cleaning so I look forward to hearing about any possible improvement before I start to blind SWMBO with man maths.
 
In a word, NO, many conditions determine your top speed such as engine output, gearing, and propeller size and pitch.

What you will notice is that a higher speed will be attained for a longer period as the coating prevents the detritus from building up on your hull which will prevent it slowing you down.
 
The issue I have with coppercoat is the appearance after immersion. It doesn't look attractive but the lack of regular antifouling is appealing.
I guess a good slightly deep in the water boot top is the answer.
 
I have coppercoat & would say no, unless what you have is rough & costing a knot or two. Due to illness my boat didn't move much for a couple of seasons but still only lost a couple of knots to fouling, so well worth doing (properly) IMO
 
In the first year, I did notice a small increase in speed at a given RPM.
But no now.

In my dinghy sailing days, decades ago, we used to paint the boats leaving an orange peel finish.
At the time, we believed that air would get trapped in the smooth indents thus making the boat slide through the water over the little air bubbles that were created.
I was never sure about that but it might be the reason CC provides more speed.

In any case, any speed increase isn't enough of a reason on its own to use CC.
You have to have other reasons to apply the product.
 
The cc leaves a smoother finish than a/f and therefore the boat should have less resistance. It is still too early to confirm any measurable difference on Rafiki.
 
The cc leaves a smoother finish than a/f and therefore the boat should have less resistance. It is still too early to confirm any measurable difference on Rafiki.

Ellesar of this parish used to be a coppercoat supplier/painter(?) he said there was a small increase in speed, but better he replies and gives us a first hand account.
 
In any case, any speed increase isn't enough of a reason on its own to use CC.
You have to have other reasons to apply the product.
Positively +1, though my first and only experience is still too short to draw any indisputable conclusions.

Otoh, the "other reasons" are plenty:
1) Stripping the hull to bare gelcoat is necessary anyway over time, particularly with planing boats. So, it makes sense to just wait till the job is due regardless, and then go for CC - this makes the stripping cost irrelevant to the comparison, so to speak.
2) CC works also as a preventative epoxy treatment - which is very good to have after stripping to bare hull anyway, regardless of the type of a/f to be used afterwards. And the cost of say a gelshield treatment followed by a decent traditional a/f is in the same ballpark cost of CC.
3) Theoretically - but as I said my first hand experience is too short to confirm - stripping to bare hull should not be necessary anymore after CC application, because it can be "refreshed" after several years, and with an appropriate hull preparation it should be possible to achieve a result as smooth as the first one.
4) Economically, it's a no brainer. The higher cost upfront is already justified after 3/4 years max - assuming to NOT make any epoxy treatment as per 2 above, otherwise it's a break even right from the beginning.
And according to all first hand experiences I gathered before going for CC, even in the worst case it lasts much longer than that.

There are only two cons I can think of:
1) much higher anodes consumption, which I heard to have happened in a couple of cases, but both with no certainty that CC was the actual culprit;
2) the color. But imho, those who are concerned about that should evaluate whether life is long enough to bother with the aesthetic of a couple of inches above the w/line... :rolleyes:
 
Positively +1, though my first and only experience is still too short to draw any indisputable conclusions.

Otoh, the "other reasons" are plenty:
1) Stripping the hull to bare gelcoat is necessary anyway over time, particularly with planing boats. So, it makes sense to just wait till the job is due regardless, and then go for CC - this makes the stripping cost irrelevant to the comparison, so to speak.
2) CC works also as a preventative epoxy treatment - which is very good to have after stripping to bare hull anyway, regardless of the type of a/f to be used afterwards. And the cost of say a gelshield treatment followed by a decent traditional a/f is in the same ballpark cost of CC.
3) Theoretically - but as I said my first hand experience is too short to confirm - stripping to bare hull should not be necessary anymore after CC application, because it can be "refreshed" after several years, and with an appropriate hull preparation it should be possible to achieve a result as smooth as the first one.
4) Economically, it's a no brainer. The higher cost upfront is already justified after 3/4 years max - assuming to NOT make any epoxy treatment as per 2 above, otherwise it's a break even right from the beginning.
And according to all first hand experiences I gathered before going for CC, even in the worst case it lasts much longer than that.

There are only two cons I can think of:
1) much higher anodes consumption, which I heard to have happened in a couple of cases, but both with no certainty that CC was the actual culprit;
2) the color. But imho, those who are concerned about that should evaluate whether life is long enough to bother with the aesthetic of a couple of inches above the w/line... :rolleyes:
All +1
 
If I strip off all the old anti foul and get Coppercoat applied can I expect a top speed increase?
If so I can then expect higher speed for as long as it continues to work which is some advantage over a few years worth of the normal stuff which gets rougher with each coat and increases drag.
Apart from that it would save a lot of effort every spring.
It is a rather expensive process especially the hull cleaning so I look forward to hearing about any possible improvement before I start to blind SWMBO with man maths.

I while back I had a business that applied Coppercoat. We did a test for MBY on Greg Copp’s sunsreker.
2 off 2 way speed runs.
First was bare epoxy, clean.
Then it was new Coppercoat. Sprayed on so a perfect finish.
The boat gained 2 knots at the same rpm.
I witnessed the speed test then took the boat for a spin, on seeing the boat photos boat I headed for it at full chat, turning hard and they photographed the still brown (launched an hour before) Coppercoat.
Coppercoat still use the photo so it’s me at the helm of the sunseeker on the Coppercoat pots, (and in the brochure, and on the boat show stand!)
So in answer to your question, it can. Makes sense as it is smooth and non porous, unlike most antifouls.
 
I while back I had a business that applied Coppercoat. We did a test for MBY on Greg Copp’s sunsreker.
2 off 2 way speed runs.
First was bare epoxy, clean.
Then it was new Coppercoat. Sprayed on so a perfect finish.
The boat gained 2 knots at the same rpm.
I witnessed the speed test then took the boat for a spin, on seeing the boat photos boat I headed for it at full chat, turning hard and they photographed the still brown (launched an hour before) Coppercoat.
Coppercoat still use the photo so it’s me at the helm of the sunseeker on the Coppercoat pots, (and in the brochure, and on the boat show stand!)
So in answer to your question, it can. Makes sense as it is smooth and non porous, unlike most antifouls.
Mark as now you no longer strip and apply CC who would you recommend in the Southampton / Hamble area ?

Paul (Rafiki) who did you use ?

If I do have it done I will replace all the seacocks with Forespar Marelon as well so my bonding circuit will then just be the stern gear. Further question for Mark will the blasting process be too vicious for the plastic through hulls, so should I install the new seacocks after blasting ?
 
I while back I had a business that applied Coppercoat. We did a test for MBY on Greg Copp’s sunsreker.
2 off 2 way speed runs.
First was bare epoxy, clean.
Then it was new Coppercoat. Sprayed on so a perfect finish.
The boat gained 2 knots at the same rpm.
I witnessed the speed test then took the boat for a spin, on seeing the boat photos boat I headed for it at full chat, turning hard and they photographed the still brown (launched an hour before) Coppercoat.
Coppercoat still use the photo so it’s me at the helm of the sunseeker on the Coppercoat pots, (and in the brochure, and on the boat show stand!)
So in answer to your question, it can. Makes sense as it is smooth and non porous, unlike most antifouls.

Interesting, last boat we had cc we also had other work such as extended swim platform & new teak at the same time, so although we didn't notice an increase in speed, neither did we notice a drop so maybe we did get an increase but just not realise.
 
First was bare epoxy, clean.
Then it was new Coppercoat. Sprayed on so a perfect finish.
...
Makes sense as it is smooth and non porous, unlike most antifouls.
In my sedate 33kts top boat, I didn't experience any meaningful improvement, but CC was rolled on and not sprayed.
Besides, drag increases exponentially with speed, was the Sskr of your test faster, maybe?

Regardless, in principle I could understand some difference when a sprayed CC hull is compared with a normal a/f.
But if compared to a bare epoxy-ed hull, it's hard to think of any plausible reasons... :confused:
 
Mark as now you no longer strip and apply CC who would you recommend in the Southampton / Hamble area ?

Paul (Rafiki) who did you use ?

If I do have it done I will replace all the seacocks with Forespar Marelon as well so my bonding circuit will then just be the stern gear. Further question for Mark will the blasting process be too vicious for the plastic through hulls, so should I install the new seacocks after blasting ?

Paul Shotton. He bought my farrow system machine. He’s the guy who extended Jimmy the Builders bathing platform on a thread on here. He’s a first rate GRP man. He doesn’t subcontract, advertise or do deals, just charges a fair - not cheap - price. He has done all my GRP work for some time. Phone no coming by pm.
 
It’s already been put Fwds ^^^^ .Its gotta be air getting into the micro golf ball dimple s .
These dimples from a even spray even not visible to the eye are enough to do the air resistance thing as the boat shifts .

Remember with underwater exhaust if done properly as Amati did it was to reduce drag primarily,let the exhaust gases gas up the rear running surfaces behind .Remember Itamas are very mid engines design the ER cutting the accommodation in two .
So s there’s plenty of L to gas up to make the aeration effect count .
2nd effect was lower sound from the exhaust a nice by product as well .

You need a flat ( wide chine ) surface behind the exhaust and a deflector plate in front of the hole .

A lot of builder fit UW exhaust for the noise benefits but miss out due to inappropriate hull shape to the real reason Amarti pioneered them - speed

So with Greggs Coops boats it will be a aeration effect .

Wether you can get that slapping CC on with a brush on a let’s face it often crappy base surface DIY prepped is another matter .
 
Mark as now you no longer strip and apply CC who would you recommend in the Southampton / Hamble area ?

Paul (Rafiki) who did you use ?

If I do have it done I will replace all the seacocks with Forespar Marelon as well so my bonding circuit will then just be the stern gear. Further question for Mark will the blasting process be too vicious for the plastic through hulls, so should I install the new seacocks after blasting ?
I used Lewis Mills. I can give you his contact details. He did a great job.
 
Remember with underwater exhaust if done properly as Amati did it was to reduce drag primarily
Not sure about how relevant this is to a thread on CC, but did Amati ever pretend that? REALLY?
Sounds like an old wives' tale to me - the kind of stuff that afaik the man never used to spread, as opposed to some other builders.
Just look at properly fast boat, and name me one with u/w exhausts, is you can. There's zero, zilch, none.
Besides, I can't see the relevance of the u/w exhaust position, because they are always (Itamas included) positioned very close to the hull sides, so the air is bound to follow the "V" path of the waterflow under the hull, going out PDQ externally, together with the water spray, regardless of their placement.
Anyhow, FWIW, the only technical reason I'm aware of for u/w exhausts (noise reduction aside) is the scavenging effect.
 
Not sure about how relevant this is to a thread on CC, but did Amati ever pretend that? REALLY?
Sounds like an old wives' tale to me - the kind of stuff that afaik the man never used to spread, as opposed to some other builders.
Just look at properly fast boat, and name me one with u/w exhausts, is you can. There's zero, zilch, none.
Besides, I can't see the relevance of the u/w exhaust position, because they are always (Itamas included) positioned very close to the hull sides, so the air is bound to follow the "V" path of the waterflow under the hull, going out PDQ externally, together with the water spray, regardless of their placement.
Anyhow, FWIW, the only technical reason I'm aware of for u/w exhausts (noise reduction aside) is the scavenging effect.

Did I mention “ aeration “ ?

Just another example of employment of that particular drag reduction tactic .
For boats that are designed to stay in the water mostly and intentionally btw .

Btw Amarti UW Exhausts have rear transome fart pipes as well to control the engine back pressure issues when pootling .
Concept has since been copied by many in a haphazard way ( if you walk round a yard see for your self ) for noise reduction primarily or enhanced scavenging as you say with little regard of the actual true raison d etre .
 
Last edited:
I perfectly understood what you mentioned, but I just happen to not buy it - on two levels:

Firstly, I don't believe that the hull aeration created by u/w exhausts can reduce drag, because due to their lateral positions only a very minimal part of the hull is affected. It's no coincidence that in order to increase aeration, stepped hulls were invented - and as you surely know, steps "cut" the whole hull transversally, not just a small external part of it.

Secondly, I don't believe that Amati ever claimed that u/w exhausts made his boat go faster, because it's akin to pretending that also the blue color made them faster, and afaik this ain't the type of snake oil that the man ever tried to sell.

Btw, idle bypass on boat with u/w exhausts is required by engine manufacturers, who wouldn't grant the warranty cover without it.
Not an Amati invention by any stretch of imagination!
 
Top