Antifouling speed log paddlewheel?

[ProDave]

A few weeks ago our speed log stopped working. It was near the end of the season so I didn't bother finding somewhere to dry out and pull the paddlewheel out and was not brave enough to do it while afloat, so waited for crane out, yesterday.

The paddlewheel was not stuck it was still free to rotate, but the reason it had stopped reading was every single "tooth" of the paddlewheel was full of tiny barnicles.

So the question is how to stop that? My only thought is an artists brush and carefully cover all the surfaces of the paddlewheel with antifoul. Any other suggestions?

 

[Sandy]

Do you not remove the paddle wheel, and replace with a blanking plate, when not underway?

 

[Alex_Blackwood]

Do you not remove the paddle wheel, and replace with a blanking plate, when not underway?

As the OP said "not brave enough to do it while afloat"

 

[ProDave]

Do you not remove the paddle wheel, and replace with a blanking plate, when not underway?

No, too many things to go wrong doing that and our home berth never completely dries.

 

[Sandy]

No, too many things to go wrong doing that and our home berth never completely dries.

Bring a friend and practice. It really is not that difficult especially as most have a flap that stops 90% of the water ingress.

You should be able to place the blanking plate in about 10 seconds.

Perhaps this activity should be an Olympic sport and have an official Guinness World Record.

 

[Neeves]

Its really not difficult and almost fool proof.

You unscrew the locking ring of the transducer, the transducer will commonly stay 'in place' (water pressure is insufficient to force it out). You pull our transducer and replace with blank component with one, or if you like 2, swift movements (one hand for each). You screw on locking ring. You maybe collect a couple of cups of water, which you mop up. Your transducer is then only in seawater when you sail, and as you are moving you do not collect any fouling.

No need to paint paddle wheel.

Thousands of yacht owner do this regularly and I have never, ever, heard of anyone making a mistake.

Jonathan

 

[capnsensible]

Practice, practice, practice. As others have said, it's easy.

 

[dansaskip]

Admittedly it is scary the first time you do it - remove paddle wheel whilst afloat that is, but a long as you are well prepared it is OK- like others I do it every time I leave the boat. Have a bucket and sponge handy to mop up afterwards.

 

[Metalicmike]

Better doing it in the water than on the dock, I refloated after antifouling and after returning to my mooring discovered my bilge full of water due to an incorrectly fitted Log. My Bilge is too shallow for the pump to work so i had to correct the miss aligned log then bail all the water by hand. Just put a big towel around it and don't panic.

 

[Sandy]

Admittedly it is scary the first time you do it - remove paddle wheel whilst afloat that is, but a long as you are well prepared it is OK- like others I do it every time I leave the boat. Have a bucket and sponge handy to mop up afterwards.

and a small dram for medicinal purposes post drama.

 

[rogerthebodger]

If you are scared of the inrush of water glue a 110 mm dia joiner over the paddlewheel fitting inside the boat. You can then fit a piece of 110 PVC pipe into the joiner that will contain any inrush of water when the paddlewheel is removed.

This is a bit overkill as Sandy says it only takes 10 seconds s long as you have the plug ready with a little of Vaseline on to eswe the plug into the hull fitting

 

[ProDave]

The issue with removing it regularly are access. It is near the front of the boat and accessed through a locker that goes across the front, under a seat. Apart from that being the resting place for the table, so that needs moving first, it is then a large cushion to lift off to gain access to the hatch. It is probably the most awkward locker in the boat to get into so one rarely used apart from one or 2 rarely used items. It is certainly not going to be added to my routine of something to do upon boarding or leaving like the sea cocks (which are much easier to reach)

The few occasions I have pulled it (ashore) it is a tight fit in it's tube thanks to the 2 O rings that seal it, and it has to go back in a certain orientation.

Perhaps the compromise is have that dram and pull it once or twice a season, when it starts to act up.

 

[Sandy]

The few occasions I have pulled it (ashore) it is a tight fit in it's tube thanks to the 2 O rings that seal it, and it has to go back in a certain orientation.

Perhaps the compromise is have that dram and pull it once or twice a season, when it starts to act up.

It should have some waterproof grease on it to allow easy extraction.

 

[rogerthebodger]

It should have some waterproof grease on it to allow easy extraction.

As in post #11 Vaseline for ease of insertion / extraction

 

[Refueler]

My 38 has TWO paddlewheel logs ... because when pressed and heeled - one log could be near surface of water ... one either side of C/L ...

I don't pull them and they get stuck with barnies .... but next year the paddlewheels will get my attention ... this year I left all to the yard. They applied a special L:anolin based product designed for such ... useless !!

My SR25 has a single paddlewheel just inside the bilge keels and my trick there : (which I will do on the 38)

Take a brush with anti-foul ... Now back and forth with the brush on the wheel - making it spin while brush is putting AF on ... this way the paddle blades get a coating .. the spindle gets a bit .. and some inside the tube ... BUT because its spinning when you do it - its not so much to 'glue it up' ... before launch - give the paddlewheel a flick by hand just to make sure its still free.

 

[Daydream believer]

Admittedly it is scary the first time you do it - remove paddle wheel whilst afloat that is, but a long as you are well prepared it is OK- like others I do it every time I leave the boat. Have a bucket and sponge handy to mop up afterwards.

I cannot see anything scary about the operation. Saying it is, just adds to the OPs fear of nothing. So it would be better not to start sympathising with nothing that needs sympathy. This is not the only post that does this.
.
A disposable nappy, with the elastic sides cut off with a pair of scissors works very well. One can curl the nappy around the unit & it normally soaks up any residue as the impellor is withdrawn, or replaced.
.
As for antifoul paint. I coat my impellor with this Eco
A small bottle lasts years provided one adds some water & stores the bottle upside down to perevent it going hard. I am still on the first one in 18 years. It works as good as any other solution that I have tried. I also make sure that I coat a small circular area around the impellor mounting so that any stray weed from the coppercoat does not block the vanes, as the boat move forward

 

[Refueler]

I used to follow this system :

Being a definite right-handed person ... I would unscrew the transducer cap until it was just about to be free with right hand. Then change to left hand - but before that last bit of thread and pull the transducer - I had the cap or plug ready in right hand ..
My SR25 where I used to pull until I started my AF trick ... being EChopilot has a screw on cap - not a plug.

My 38 has push in plugs without any cap. Not something I like ..

 

[Major Tom]

Leaving the speedo/transducer in will inevitably affect accuracy, even with light fouling, and stuff up modern chart plotter derivations from it - so I remove it every time. However, one of the O rings of the blank once jumped out of its groove and after two weeks, allowed about 20 litres in. Lucky it wasn't longer as the water would have reached the bow thruster and spilled into the cabin.
Wherever possible, I put the blank in a hour or two before leaving the boat, so I can check for leaks.

 

[Laysula]

I don't think that mine has been in for the last five or six years. Quite happy with the SOG from the GPS.

 

[Neeves]

I don't think that mine has been in for the last five or six years. Quite happy with the SOG from the GPS.

Speed from the GPS is speed over the ground, or in this case 'seabed'. . This is obviously useful but it does not give you speed through the water - you don't know if you are benefitting from a current, or tide - or the opposite. We have a current from north to south down Australia's east coast, it moves warm tropical water from north to south and is imaginatively called The East Australian Current. It can flow at 5 knots and if you are sailing south you want to be 'in' the current. It generally is at its fastest at around the 100 fathom line, which makes a good reference contour, but can also be defined by water temperature, from the log. If you are sailing north the practice is to tack into the bays and stay close to the headlands (following the whales as they move north).

Current temperatures are available and using a combination of speed, inshore (no current) temperature, offshore temperature, and depth gives a good idea when you are in or out of the current.

The EAC is not unique, but is 'big' and relying only on GPS misses some of the nuances.

We have another tidal flow on NW Tasmania (with a similar flow in NE Tasmania) when all the water in high tide Bass Strait rushes through the Hunter Passage at 10 knots to empty into the Indian Ocean. The flow is extraordinary as you 'sail' at over 12 knots with no wind and no engine - and the water is 'seemingly' a flat calm - until you reach the overflows! Its all well documented in the Admiralty Pilot for Tasmania.

Joanthan