Echo Sounder Transducer

[Balbas]

I've bought a new NASA Clipper depth sounder, which came with a transducer which I intend to fit (the existing one isn't working so far as I can tell). The instruction manual gives 3 options:-

1) The transducer face can be bonded directly to the inside of the hull.
2) A through hull mount is available from your dealer
3) The transducer can be positioned inside a GRP hull by means of an in hull transducer kit

2) is out, I'm not drilling a big hole in my boat whilst its in the water.
3) I'd rather not bother with unless I'm persuaded otherwise
1) is my preferred option. What should I use to bond it to the hull and are there any 'gotchas' to be aware of?

Thanks

 

[pvb]

Try a blob of silicone sealant.

 

[Balbas]

Try a blob of silicone sealant.

Under the flat face of the transducer, so effectively being the 'jam' filling in the transducer/hull sandwich?

 

[pvb]

Under the flat face of the transducer, so effectively being the 'jam' filling in the transducer/hull sandwich?

Yes, that's the idea.

 

[Balbas]

Yes, that's the idea.

Thanks. I'll take a tube of skiaflex with me when I'm next down at the boat.

 

[pvb]

Thanks. I'll take a tube of skiaflex with me when I'm next down at the boat.

I don't think that's a good idea. Nasa make their plastic out of recycled butterfly wings and it's rather fragile - and very prone to attack by stuff like Sikaflex. So stick to ordinary common or garden silicone sealant.

 

[Stemar]

I used the Gosport Pound shop's equivalent of No More Nails. It worked for years. The important thing is to ensure there are no air pockets. You'll probably want to put it in the corner of a locker and use more goop to hold it to the sides, or it'll get knocked loose.

An alternative is to get a suitable rigid tube and epoxy it to the bottom of the hull. Pour in a few ml of your preferred vegetable oil and dunk the transponder in. The oil level will need to be topped up once in a while.

 

[PaulRainbow]

The correct stuff to stick it with is slow drying epoxy, slow drying to allow any air bubbles to get out. Airmar, the biggest manufacturer of transducers specifically advise against the use use silicon sealant, it can dampen the signal.

 

[agurney]

I'm all for the silicone sealant, however, whatever the method you end up using it's a good idea to test for the best location using the transducer in a poly bag with water first.

 

[Balbas]

It occurred to me that as well as asking you lot I probably ought to ask NASA. This is what they said:-

A quick setting epoxy resin,although mounting it with an In hull mounting kit would be preferable. These are available direct from our website.

So I guess I'll be buying an in hull kit then.

 

[peteK]

No need to go too the expense of ordering a kit just fix a suitable plastic tube in place with polyester resin or epoxy,as that is all the kit is.