Mounting A Shoot Thru Transducer

[four winds]

Rod, reading your posts and have a question.

Are you saying a transducer can fail if allowed to ping across an air gap? Such as when the transfer liquid has escaped and there is no really solid mounting. Like my transducer affixed only at the corners and water in the gap, that may but has not yet escaped.

[brianlara 3]

Originally Posted by ramblinrod

Yes, epoxy resin will work.

The energy transfer through epoxy may not be quite as good as through polyester resin.

One of the key reasons I avoid epoxy use is the risk of becoming sensitized to it. I know people who have become so sensitized to epoxy that now (and presumably for the rest of their lives) can't go anywhere near it (several hundred feet) without severe reaction.

There are very few applications where polyester resin can't be substituted for epoxy, and certainly where epoxy doesn't need to be substituted for polyester. There are certainly applications where epoxy CAN'T be substituted for polyester.

With my background of laying-up as a youngster and later having owned more than a few copies of Gougeon Brothers on Boat Building....I'm now just an epoxy devotee.
And Rod, surely you'd agree that epoxy bonds to polyester more efficiently than a poly/poly bond. Yes?

[ramblinrod]

Originally Posted by four winds

Rod, reading your posts and have a question.

Are you saying a transducer can fail if allowed to ping across an air gap? Such as when the transfer liquid has escaped and there is no really solid mounting. Like my transducer affixed only at the corners and water in the gap, that may but has not yet escaped.

Well, some high power sonars can damage the transducer if it is left to fire in open air for considerable time (days), but the real issue is that any air gap or bubbles between the transducer face and the transmission medium will severely attenuate the signal. (IOW, it won't work.) In effect the sound wave (in air) bounces back and forth between the hull and transducer until it dissipates rather than coupling and transmitting through the hull.

[ramblinrod]

Originally Posted by brianlara 3

With my background of laying-up as a youngster and later having owned more than a few copies of Gougeon Brothers on Boat Building....I'm now just an epoxy devotee.
And Rod, surely you'd agree that epoxy bonds to polyester more efficiently than a poly/poly bond. Yes?

The Gudgeon ;-) Brothers have done a great job marketing epoxy, convincing many that this is the only material that can or should be used to repair a polyester resin boat.

IMHO, this notion is incorrect.

A properly prepared polyester resin FRP mechanical bond is as strong as the materials bonded.

We perform almost all FRP repairs using polyester resin. Never had a failure.

I must admit that I sometimes use 5 minute epoxy to bond electrical tie wrap cradles to FRP, just because it cures so fast.

But I will extend this warning to all, when working with epoxy, use proper protective clothing and an organic mask, because the day one turns sensitive to this stuff, will be the last day they'll be able to go anywhere near it while its curing, and depending on conditions, it may not fully cure to the point one won't be sensitized for weeks.

[brianlara 3]

Originally Posted by ramblinrod

The Gudgeon ;-) Brothers have done a great job marketing epoxy, convincing many that this is the only material that can or should be used to repair a polyester resin boat.

IMHO, this notion is incorrect.

A properly prepared polyester resin FRP mechanical bond is as strong as the materials bonded.

We perform almost all FRP repairs using polyester resin. Never had a failure.

I must admit that I sometimes use 5 minute epoxy to bond electrical tie wrap cradles to FRP, just because it cures so fast.

But I will extend this warning to all, when working with epoxy, use proper protective clothing and an organic mask, because the day one turns sensitive to this stuff, will be the last day they'll be able to go anywhere near it while its curing, and depending on conditions, it may not fully cure to the point one won't be sensitized for weeks.

That'll do me!
Thank you Sir.

[fishsail18]

UPDATE!, Looking in my bilge I noticed a puddle of water laying just on the outside of the stringer. I thought I wonder how it reads here. I hooked it up and seems to be good, I ran the wires thru the boat and went for a sail. No problems, didn't use anything to hold it down it just sit in water under a couple hoses worked great. Even caught a nice kingfish for dinner.

[sailjumanji]

One final note. I have one of those Garmin clearvu sidevu downscan chirp transducers. Talked to Garmin about inside hull mounting and they recommended strongly against. Apparently that transducer generates heat and needs to be cooled by water. Said it would probably fail within a year otherwise.

[kclancy]

Does the orientation of the transducer make any difference?

I am wondering if I should try to keep it pointed in the same direction as it would be if I had mounted off the transom.

Thanks!
Kevin

[AedanC]

Ours is an external type mounted internally and it works perfectly. I was careful to keep it the right way up as I suspect it might be important. That's based on gut feeling rather than any great knowledge.

[Stu Jackson]

[QUOTE=kclancy;2289977]

Originally Posted by Stu Jackson

toilet bowl wax ring

I've never had a chart plotter, but received one for Christmas. Did you put the transducer inside the ring on the hull and the massage the wax to cover the transducer? I'm trying to imagine how this works. I want to try this before other more permanent installations. Thanks!

No, the idea is to use just the wax ring material, as if it was the silicone or oil, plumbers putty or water mentioned in other posts. You could buy a full wax ring or just a bunch of the material which is also sold without the built-in ring shape.

[belizesailor]

Temporarily mounted one (not the same model) in my boat years ago. Used silicon in the integral to hull shower sump. This way there is usually water between the hull and transducer. Was meant to be temporary, but worked so well I never changed it...that was over a decade ago!

[kclancy]

Originally Posted by Stu Jackson

toilet bowl wax ring material

I tried using the toilet bowl wax ring. It didn't work for my tranducet. On to the next option.... =)

[double u]

Originally Posted by kclancy

Does the orientation of the transducer make any difference?

I am wondering if I should try to keep it pointed in the same direction as it would be if I had mounted off the transom.

Thanks!
Kevin

that matters only with side- or downscan transducers, & they don't work through the hull anyway. all the others ("dual or single beam" have circular elements that send in a cone-shape, very often 60 & 20°)