Log paddlewheels...why not copper?

[Shearwater]

Having had the boat antifouled and returned to the water 4 weeks ago, the paddlewheel is already jammed with tiny barnacles so it looks as though I'll have to remove and clean it with annoying regularity and it's in a really awkward and confined space. As the tolerance between the wheel and the supporting cheeks are such that two layers of a/f would jam the wheel anyway, there's no point in slapping paint all over it.

But as most living organisms don't like copper then why isn't it used moving parts such as these, or teflon or something modern i.s.o. old fashioned plastic ?

 

[pvb]

Good question. But the housing would still foul. I don't know how thickly you apply your antifoul, but I've always found that antifouling the transducer works well for several months, and never jams the paddle wheel.

 

[Halo]

Initial thoughts are
1. The dreaded tube worm goes for metal like crazy. I know that copper is the basis of antifouling and was proven to be worm proof in the days of "copper bottomed investments" but suspect the worm would move in pdq.
2. The other possible reason is electrolysis. Different metals in salt water coupled with electonics ?? Props seem to need zonc anodes and I would not want to put oe on a log paddle wheel

 

[prv]

"Water-based transducer paint" has kept my log spotless so far, since the end of March.

Pete

 

[geem]

Copper is a conductor. How is the transducer going to pick up the electrical pulse as the wheel goes around?

 

[Seajet]

Pete,

just for interest - as I haven't got an in hull log and would need a gun to my head to ever have one again, useless liabilities in my experience - what ' water based transducer paint ' was that then ?

Andy

 

[prv]

what ' water based transducer paint ' was that then ?

Yes, it was a rather brief post made from my phone

However, the first hit on google for the phrase happens to be the one I use: http://www.westmarine.com/buy/mdr--transducer-antifouling-paint--128225

It goes on very thin so it won't gum up the works, and it seems to do the job.

I bought it in the UK via eBay.

Pete

 

[RichardS]

Copper is a conductor. How is the transducer going to pick up the electrical pulse as the wheel goes around?

Isn't the pulse generated by a magnet buried in the plastic of the paddlewheel? As copper is not magnetic you could equally well bury the magnet in the copper.

Richard

 

[Seajet]

Yes, it was a rather brief post made from my phone

However, the first hit on google for the phrase happens to be the one I use: http://www.westmarine.com/buy/mdr--transducer-antifouling-paint--128225

It goes on very thin so it won't gum up the works, and it seems to do the job.

I bought it in the UK via eBay.

Pete

Hi Pete,

thanks I'll file that away for future reference; now all we need is ' Wizard Boundary Layer Paint ' to make the things work even vaguely realistically !

Andy

 

[johnalison]

My transducer has been in since May. We have been to the Baltic which is a low fouling area and back for the last fortnight. It was still working a few days ago in spite of not having been retracted all season. They are not completely useless.

 

[SAMYL]

Paint the paddle wheel with some Waxoyl.

Works for props too.

 

[Daydream believer]

Pete,

just for interest - would need a gun to my head to ever have one again, useless liabilities

I am sure the forum could sort something along those lines for you?

 

[Seajet]

If you give me a few spare magazines first ( bullets, not Playboy ) and the addresses of a few forumites, I might go for it !

As for painting paddlewheels with Waxoyl, my first reaction was ' what about the calibration ? ' then I remembered how useless my Smiths paddlewheel job had been; one might as well tar and feather it, still just as accurate...

 

[FulmarJeddo]

"Water-based transducer paint" has kept my log spotless so far, since the end of March.

Pete

I also used a water based antifoul (ECHO) on my paddle wheel. After an initial bit of binding where I think I put a bit too much on, it has worked every time I have used the boat since I launched at Easter. I haven't had reason to pull the transducer out so couldn't say if it's still spotless or not. I thought £15 seemed a lot for the tiny pot, but from the results so far, it was money well spent. If it doesn't dry out the pot should last for quite a few years.

 

[vyv_cox]

Because I have a small tin of Velox for my propeller, which I find works well on other things too, like P-brackets, I also use it on my combined log/depth transducer, where it is very effective, even with a single coat.

 

[MM5AHO]

Sailing on the various Lochs that join the bits of the Caledonian canal last week, I wondered about the difference between a log in salt versus fresh water. Does the density difference between these waters make any difference?

 

[Jabs]

Its a bit extravagant but frankly an ultrasonic transducer is the answer to this conundrum.

My first fit was without antifouling and when we hauled the boat, there was a foot of growth on the Transducer, just on the round bit. It was still working perfectly!

What more can I add.

Tony.

 

[AngusMcDoon]

As for painting paddlewheels with Waxoyl, my first reaction was ' what about the calibration ? ' then I remembered how useless my Smiths paddlewheel job had been; one might as well tar and feather it, still just as accurate...

Things have moved on in the last 40 years. Paddle wheel logs work fine. 97.3% of sailing boats have them (a statistic made up just now). The best way to stop them fouling is not to leave the boat stationery for long. Sail every suitable day all summer. That's what I do and mine never fouls. It stops most hull fouling too. How's your sailing been this summer on your boat?

 

[Seajet]

I have also been around for the last 40 years sadly ...

Quite a while ago Brookes & Gatehouse came out with an on-hull log system of 2 sensor plates a few inches apart, going by doppler effect; I don't know why it didn't catch on; maybe the high price, critical hull positioning ( I personally think the most likely snag ) or antifouling over the important bits !

 

[agurney]

Sailing on the various Lochs that join the bits of the Caledonian canal last week, I wondered about the difference between a log in salt versus fresh water. Does the density difference between these waters make any difference?

I can't see density making a difference, but if you regularly move between fresh and salt you can away with not antifouling for years on end (probably the only benefit of a berth at Bellanoch, other than the shelter).