Rafiki Coppercoating

jfm said:
No, you're not missing anything. But we're looking for a few % difference here so you have to sure that AOTBE before coppercoat gets the cigar. Weight, air temps, tide effects, etc.
I'd expect something like 3% (which is a hunch number) from CC because it is smooth whereas normal a/f applied slapdashly is pretty rough. Down here in Med it costs a lot to have the a/f sprayed, but it can be done (MM/Trehard in Antibes did it to a racy dayboat boat belonging to a friend of mine but he is Royal Huismaned up and not very worried about yard costs!).
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Thanks JFM, and yes, all agreed. I do agree/think that some portion of the CC extra slipperiness comes from the hull prep and spraying as you say. In my case I will still be on full fuel and water, maybe some difference in wind and tide and air temp but I will run in both directions and use an average same as I did the first time. And If I get an extra knot and a half (approx 3%) I will be delighted !
 
Doh, sorry.
I guess you already said that in the past and I should remember, but I'm afraid I don't now.
What sort of rocketship is she? :encouragement:

Edit: apologies T, now it popped to my mind, what I actually forgot is just the association with your username.
The day I'll forget a triple Trimax boat, I'd better move to pipe and slipper forum... :D
 
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MapisM said:
Do you mean completely non-connected, or you've got valves on the connecting hoses which you decided to keep close?
If the first, it doesn't sound very convenient, because I guess that refilling is bound to be a two steps process on both sides, unless I'm missing something... :confused:

Fwiw, I concur with jfm that 15% sounds way too much to put it down to different tolerances between the two engines.
Particularly if they are both the originally installed ones btw, because Cat delivers them to builders in matched pairs.
Well, I suppose not just Cat actually, but I'm sure about Cat...
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No connection. I have to fill the tanks separately, which is a pain, but enables me to understand fuel use difference port to stbd. There may well be a tacho difference, and of corse I could swap the connections at the helm to check. JFM May have a strong point re pro0 differences, and maybe worth checking at some point. However performance is good, fuel cons ok, so no strong motivation to do much.
 
rafiki_ said:
I would expect to see a difference in temp with an engine working 15% harder.
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The engine can indeed generate more heat, but I'm with jfm on this.
Since the heat exchangers are designed to cope with up to 2800rpm/100% load, they are bound to be well within their limit at cruising speed.
In turn, this means that the thermostatic valve keeps the closed circuit liquid at (say) 85 deg, so you will see 85 on both engines regardless of whether one is actually working harder or not.
Different story with EGT as I said (which is in fact one of the reasons why I'd like to fit EGT probes in my boat btw), but normally you can only see that number on the displays of electronic engines.

PS: understood ref. tanks. :encouragement:
 
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Hey Paul, Rafiki looking in great shape' be interested in hearing your findings post copper coat, there are qui a few wearing it here in Portishead, we have a local lady who applies it and people seem v pleased with their results
 
Sneds said:
Hey Paul, Rafiki looking in great shape' be interested in hearing your findings post copper coat, there are qui a few wearing it here in Portishead, we have a local lady who applies it and people seem v pleased with their results
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Yep, Ray Tanner on Black Pearl and Andrew on Volante have both cc’d. Not sure about others, but I have been away nearly 2 years.
 
A Fairline Squadron, freshly CC'd was Launched on Friday, as I said be v interested in how you get on

I'm still doing the maths!
 
Spare Thyme said:
Paul, Re the odd fuel usage I had the exact same on my Azi, only it was the port tank that seemed to empty faster, this winter I fitted both tanks with OS capacitive level sensors and did a bit of investigation over the past few weeks, I found the breather line that runs from the tank to the vent had a low point, lower than both the tank outlet and outside vent, if you overfilled the tank at any time this caused an air lock (low point of breather line filled with fuel) just enough for it to be easier for both engines to pull from port tank, each engine returns to its own tank, so relieves the air lock a bit, so you pull a little from the locked tank. Have a look at the run of your breather hoses, is the a low point?
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John, apologies, I missed this. Am on board this weekend and will have a look at the hose runs.
 
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