Depth transducer

[joe17]

Anyone tried mounting a depth transducer on top of a gel cool/heat pad?

What I mean is replacing the water or oil in a pipe method with the transducer sitting on top of one of the gel filled pads you get to treat muscle injuries? I was thinking it might be a cleaner approach as I have struggled to get my pipe to stay bonded to the hull and get a good seal on the fitting at the top of the pipe.

As I understand it then the water (or oil) is just there to make sure there is a good "sonic" connection to the hull and therefore the sea. The gel pad could do the same job???

 

[prv]

Not sure you'd get an air-free connection between the transducer and the bag or the bag and the hull. But I have heard of using a big blob of silicone in the same way, sticking the transducer into it.

Pete

 

[SHUG]

Interesting idea. Why not try it and report back

 

[BruceDanforth]

Mine is just glued to the inside of the hull with some kind of silicone.

 

[electrosys]

It might be worth experimenting with ...

I've heard of people holding a transducer against a bag filled with oil or similar, to test sites around the hull before settling on one at which to do a permanent install - IIRC, they still had to put a smear of grease on the face of the transducer to mate it to the bag - as Pete has cautioned about.

 

[Caer Urfa]

Anyone tried mounting a depth transducer on top of a gel cool/heat pad?

What I mean is replacing the water or oil in a pipe method with the transducer sitting on top of one of the gel filled pads you get to treat muscle injuries? I was thinking it might be a cleaner approach as I have struggled to get my pipe to stay bonded to the hull and get a good seal on the fitting at the top of the pipe.

As I understand it then the water (or oil) is just there to make sure there is a good "sonic" connection to the hull and therefore the sea. The gel pad could do the same job???

To find the best position for an 'in hull' Transducer I used 'Blue tack' then finally used Sikaflex for the final installation.

Tips: clean the bilge area before final contact, wriggle transducer into the silkaflex to remove any possible air bubbles, leave to set overnight with some fixed temporary supports.

Following day I built up the sides more with sikaflex around the transducer so it could not move, after 7 years still works well.

Mike

 

[joe17]

It might be worth experimenting with ...

I've heard of people holding a transducer against a bag filled with oil or similar, to test sites around the hull before settling on one at which to do a permanent install - IIRC, they still had to put a smear of grease on the face of the transducer to mate it to the bag - as Pete has cautioned about.

Yes, I have tried that and it worked OK (By worked I mean it gave the depth I expected in my berth).

I will give it a go at the weekend and report back. Reason for the post was "thinking aloud" as I am not close to my boat right now.

Using Sika directly might also be a good option. Sika is strong and long lasting, but ultimately removable and cleanable with something (white spirit?).

Certainly cant be bothered with the pipe approach anymore.

Thanks for the thoughts.

 

[nimbusgb]

@electrosys - To test locations put the transducer #into# a plastic bag of water.

If you use a lightweight clear polythene bag it sits very well on the inside of a hull and forms an 'air free' link to the skin.

Surprising how well this works. When mounting an internal depth transducer recently inside a heavily built hull it took some fiddling to find a place that the transducer would shoot through happily!

 

[joe17]

This is a reply to an old thread I made a year ago.

I was going to bind the transducer to the hull in a bed of sikaflex. It seemed to be too permanent and/or messy, so in the end I actually put the transducer in cling film and used it as a mould for a base. I brought the sikaflex up round the sides and over the top a little.

When it had all gone off I removed the transducer from the base, removed the cling film and then plugged the transducer back into the sikaflex base.

It didnt work! Obviously still too much air between the transducer and the sikaflex.

After leaving it a few days I had an alternative idea and poured a little bit of water onto the mould and replaced the transducer. It worked! It has continued to work now for a month or so without replacing the water.

Sooner or later it will evaporate and the connection will be lost and it will stop working. My next experiment will be to replace the water with vaseline.

I am not sure why anyone would do this. I just want to make sure the whole depth setup is easily removable on my boat.

 

[Moonbeam]

I fixed my in hull transducer with 'plumbers mate' putty (same as window putty). It was meant to be temporary solution before fixing it in a more seaman like fashion. That was two seasons ago! It works too well, it's removable and I have no plans to improve on it.

 

[Spi D]

Fixed with Sika, filled with coolant mix 50:50 as per transducer manufacturer instructions. Works perfectly and no harm done if leaking.

 

[geoffatstanpit]

I used Blu-Tack so I could try different places to find the best. It worked fine and as far as I know it's still there - sold the boat!

 

[Stemar]

Mine's been mounted in a blob of the Gospert Poundshop's version of No More Nails for the last 5 or more years.