Raymarine Through Hull Speed Sensor should I antifoul it or not?

[The Third Man]

My boat has Raymarine ST60 instruments. I have owned her from new and she is now five years old. I followed the manufacturer's instructions regarding antifouling the through hull fitting with water based antifouling but it seemed ineffective. So after about three years I used normal anti fouling applied thinly but that also seemed ineffective. When I say "ineffective" I realise that I need to withdraw the sensor and clean it periodically but the amount of growth has always seemed excessive and so the task has been greater than I would have hoped.

Bearing in mind that the Einstein definition of insanity is "doing the same thing over and over again and expecting different results" I feel disinclined to continue as I have for the past five years.

I have recently been advised that I would be better off not antifouling it at all which sounds bit suspect to me.

I am considering simply spraying it with Sailkote as that has worked wonders on my mainsail track and the manufacturer claims it is good underwater.

Does anyone have any thoughts on the matter?

 

[FWB]

On past boats I've owned I found that antifouling a paddle log was reasonably effective, but as you say you still need to clean. My present boat with Raymarine kit has an ultrasonic speed transducer from new. It's like the depth transducer and needs no attention. Expensive, but well worth it.

 

[prv]

Not antifouling it won't work. Accidentally missed out doing ours last year and it would block solid within a week.

Pete

 

[Bobc]

I feel your pain.

I gave up eventually, pulled it out and put the blanking plug in, and haven't bothered with a log since.

 

[pvb]

I antifoul the impeller and housing a couple of times a year.

 

[BrianH]

I gave up eventually, pulled it out and put the blanking plug in, and haven't bothered with a log since.

As did I and do not miss it - I certainly do not miss the constant withdrawal to clean and the mopping up after. The plotter gives a clear figure for SOG and as there is so little tidally-induced streams where I sail to think I need to know my speed through the water.

 

[vyv_cox]

I have extolled the benefits of Velox prop antifouling several times here, and in a YM article last month that has apparently drawn several enquiries. When I first tried it three years ago I did the prop only. It was so successful that I have steadily increased the number of items I used it on to include the P-bracket, part of the prop shaft, a small area on top of the rudder that is loved by barnacles and finally, last season, the log impeller. It has been totally successful in every case, attracting no fouling whatsoever. Unfortunately the log impeller was destroyed half way through the season when relaunching, but after three months of use it had not been necessary to pull it once for cleaning.

 

[BERT T]

I have extolled the benefits of Velox prop antifouling several times here, and in a YM article last month that has apparently drawn several enquiries. When I first tried it three years ago I did the prop only. It was so successful that I have steadily increased the number of items I used it on to include the P-bracket, part of the prop shaft, a small area on top of the rudder that is loved by barnacles and finally, last season, the log impeller. It has been totally successful in every case, attracting no fouling whatsoever. Unfortunately the log impeller was destroyed half way through the season when relaunching, but after three months of use it had not been necessary to pull it once for cleaning.

Vyv, when applying Velox to the log impeller did you coat with primer first or just the Velox?

 

[vyv_cox]

Vyv, when applying Velox to the log impeller did you coat with primer first or just the Velox?

For the impeller, just Velox. It falls off metal without the primer.

 

[Jamesuk]

I pull it out everytime I'm in a marina plug it in when I'm off sailing

 

[eddystone]

I have extolled the benefits of Velox prop antifouling several times here, and in a YM article last month that has apparently drawn several enquiries. When I first tried it three years ago I did the prop only. It was so successful that I have steadily increased the number of items I used it on to include the P-bracket, part of the prop shaft, a small area on top of the rudder that is loved by barnacles and finally, last season, the log impeller. It has been totally successful in every case, attracting no fouling whatsoever. Unfortunately the log impeller was destroyed half way through the season when relaunching, but after three months of use it had not been necessary to pull it once for cleaning.

I thought you weren't supposed to anti-foul the shast for some reason

 

[BelleSerene]

SailKote (a PTFE) lubricant) working underwater doesn't mean it'll repel living organisms - but worth trying on your Einsteinian principle!

I too have to clean mine every now and then, in a bowl of water from the kettle and with a toothbrush I keep in the bilge for the purpose. Very occasionally in the winter, to pretty much weekly in the summer. I sometimes (not enough?) spray it with an aerosol tin of International antifoul.

 

[prv]

I too have to clean mine every now and then, in a bowl of water from the kettle and with a toothbrush I keep in the bilge for the purpose.

I find an overnight soak in a glass of Coke is great for dissolving away tubeworms

Pete

 

[vyv_cox]

I find an overnight soak in a glass of Coke is great for dissolving away tubeworms

You need to be careful using strong chemicals like Coke. I find hydrochloric acid to be far more gentle in its action

 

[DJE]

Since I fitted the ST60 log to replace the old Stowe system I have been taking the transducer out and fitting the blanking plug every time I leave the boat. The flap inside the through-hull fitting reduces the water ingress to a couple of sponges worth at each fitting or removal. I have a label on the display head cover to remind me to do it before I leave the boat.

 

[vyv_cox]

Since I fitted the ST60 log to replace the old Stowe system I have been taking the transducer out and fitting the blanking plug every time I leave the boat. The flap inside the through-hull fitting reduces the water ingress to a couple of sponges worth at each fitting or removal. I have a label on the display head cover to remind me to do it before I leave the boat.

I only leave my boat once per year, arrive in April, leave in October. My impeller is down throughout that time, in warm water. In the past I have antifouled it with limited success, cleaning it a few times per season. One problem with that is that both eroding and hard antifouling paints are quite viscous, the final film changing the performance of the log. A secondary advantage of Velox is that a very thin film can be applied with a small brush.
To shortcut any accusations, I am only a customer of Velox, no connection with them whatsoever. I have been most impressed by the product since buying my only tin of it.

 

[prv]

One problem with that is that both eroding and hard antifouling paints are quite viscous, the final film changing the performance of the log. A secondary advantage of Velox is that a very thin film can be applied with a small brush.

This year I bought some special transducer antifoul. It comes in a smallish bottle with a tiny brush in the lid, and it goes on very thin. They recommend two coats.

The boat is not yet in commission (engine bay stripped out for soundproofing) so I have the blanking plug in, which I also painted with the same stuff. It'll be interesting to see in a few weeks how that looks when I swap them over!

Pete

 

[DJE]

I only leave my boat once per year, arrive in April, leave in October. My impeller is down throughout that time, in warm water. In the past I have antifouled it with limited success, cleaning it a few times per season.

When I'm retired I'm going to take the transducer out every night.

 

[BelleSerene]

At the risk of thread drift, I have to say, when I unscrew the Raymarine impeller unit from the hull every week or two in the summer, I do wonder whether I'm creating a structural weakness. Of course I only screw it in lightly hand-tight, but any thread will only last so many operations, plastic ones especially!

What does the panel think?

 

[Lodesman77]

The whole point of having such an arrangement is that it's easily removable. So why do people leave it in?