Transducer mounting

[Dalfred Ross]

I saw a post by Red Fox about installing a shoot thru' the hull transducer in his boat. Can anyone tell me the details (location, mounting substance, etc.) or can anyone tell me how they did it and how it works?
Also does anyone know the thickness of the balsa core on a 1985 22' angler.

 

[Sunbeam]

Can anyone tell me the details (location, mounting substance, etc.) or can anyone tell me how they did it and how it works?

The shoot-through-the-hull transducers rely on being able to send their signal through a solid material. Fiberglass is one such material, but wood/core is not. So you would need to mount it in an un-cored area, or else make an un-cored area by removing core (could fill back in with thickened epoxy).

I can't speak to a Classic, but on my Cruiser (from what I understand) the area under the V-berth is un-cored. I know from cutting into it that the depressed bilge sump on my boat is cored (just thinner core than the main parts of the hull).

Another consideration is an area that will get a good signal and different speeds and hull angles. I don't have experience with this on the C-Dory. On boats with a lot of solid areas to choose from, I have put the transducer in a Zip-Loc bag of water and moved it around until I found a good spot, then set the puck in epoxy (people often seem to use silicone, but from what I understand that entrains more air which may degrade the signal).

Sunbeam

 

[jerry97230]

On my 22 cruiser, I just set the transceiver on the floor in the sump for the bilge pump under the sink, and left it half full of water.
This supposed to be temporary until I get the boat out of the water to install the trans outside.
It has worked well for a year, just must keep some water in the sump.
Jerry

 

[Sunbeam]

On my 22 cruiser, I just set the transceiver on the floor in the sump for the bilge pump under the sink, and left it half full of water.

Well that is interesting. On my 22 the aft sump (at the transom drain) was cored (just thinner core than the rest of the hull), and so I assumed the mid sump (under galley) was as well. Just figured they would both be made the same way. But... maybe not if they were trying to make that sump as deep as possible (given that it's already not at the lowest point so needs all the help it can get). Guess I'll have to measure to find out. And then... I wonder if yours is cored, and if so, I'm surprised the transducer is working well.

Sunbeam

 

[Captains Cat]

As I recall, Greg (Redfox) installed it just inside the stbd cabin rear bulkhead under the sink enclosure. He drilled (very carefully) about a 3" dia hole through the inner skin and just up to but not through the outer skin. There used to be a video on YouTube which was great but it's not there any more. He then potted it in epoxy up against the skin. His comment was that it worked better than any other arrangement he's had. As I recall, the inner skin was abt 3/16" thick, the core about 1/2-3/4". He did it waterborne, as I said VERY CAREFULLY!

Here's the LINK to the thread. Maybe someone saved the original video?

Charlie

 

[Sunbeam]

As I recall, Greg (Redfox) installed it just inside the stbd cabin rear bulkhead under the sink enclosure. He drilled (very carefully) about a 3" dia hole through the inner skin and just up to but not through the outer skin.

I did something similar in my aft bilge sump, although the purpose was not to mount a transducer. That is, I cut out the upper skin and removed the core, then bonded in new fiberglass right on top of the former lower skin. It's not particularly difficult, and in a small area it's easy to make up the lost strength. No video, but there are some photos and description in my "Sunbeam ~ 22 Cruiser" thread.

I guess I could mount a transducer there now (in fact, I just thought of this the other day as I was making up a Starboard™ block for my transom-mounted transducers).

Sunbeam

 

[Anonymous]

uhoh We switched internet earlier this year and I forgot this site has only my old email... I'm not mad at anyone

I did cut out the wood core right to the glass and sealed it all up the best I could. The core was marine ply, very tough, not balsa.

The tool of choice was first a hole saw, and then a rasp on a vibratory tool.

Very satisfactory performance shooting-through the remaining 1/4 inch glass. I do loose the bottom lock when I get a certain speed though, but that don't matter.

If ya get this and still want to see the vid, let me know, I'll see if i can put it back up.

It is located about half way and on the starboard side about 20 iches or so from the hull, inside the cabin, about an inch from the bulkhead.

 

[ghone]

Not sure about the classics but my '09 19 and '11 22 I epoxied the transducer in hull under the vee berth starboard side. The core transitions to solid glass just ahead of the bulkhead. I used marinetex epoxy and pressed it with the transducer to be sure of no air voids. It is right down in the corner of the compartment ( no foam) where it is safe Let it cure a bit and round off the squish out for a nice fillet. Trouble free 1/2 hour install. So far at cruise I see numbers. It will loose it sometimes at wot but that's not what I need a sounder for. I used the bulletproof Humminbird 160 in both boats. I even get temperatures as it's reading hull temps. When it says over 72 I can go swim. When it says 0 I'm on the trailer in Montana or Alberta and it's cold! George