depth sounder

[davesail]

Anyone ever epoxy a transducer to the inside of the hull
did it work?

 

[Northern Spy]

I used beeswax as a temporary mount for a year or so. If you use epoxy make sure there are no air bubbles and that the hull has no core or delamination. I even had mine in a baggie full of water with s rubberband for a while. Do some trials before you epoxy.

 

[jwnall]

Some places on the hull are better than others, so experiment with different locations before deciding on the permanent location. That said, it works just fine if you can get the right spot. I echo what Northern Spy said, by the way.

John

 

[awpptdt]

Anyone ever epoxy a transducer to the inside of the hull
did it work?

Yes, I did, years ago, works great. I sanded the hull inside nice and smooth then used grease to shoot thru the hull to make sure there were no delaminations that would prevent proper operation. Then I cleaned the inside really good, built a box to poor the epoxy into with a board across the top to hang the transducer from. I mixed the epoxy very slowly so as to not put air bubbles in it the porred the epoxy into the box. Lastly I hung the transducer down into the epoxy with the board holding it nice and straight pointing down. Oh, be sure to paint wet epoxy all over the transducer so as you lower it into the box no air bibbles form on it's face.

 

[IntervaleII]

I also installed one with my ray marine dept finder. I installed it about 10 years ago and it has worked flawlessly. Following instructions and the prep is key, also use the proper oil to fill the void, I believe it was castrol oil. I have a second redundant system with the traditional thru hull transducer and I see no difference, and at times I think this one is more accurate and never acts up.. This system actually works better when you get bubbles or mud churning up below the hull, the traditional one sometimes zeros out in these conditions..

 

[Ben]

I asked the same questions. I just mounted a transom transducer last weekend.

1. I already had it - came with the sale.
2. I was unsure of the reliability of an in-hull unit and all the machinations to do it correctly
3. The transducer measures water temperature and my family and I like to swim.
4. Wiring cable was time consuming, but either job would be.
5. It works freaking great. I am so happy. I advanced 15 years in technology in just a day. My old depth finder was mid-90s vintage.
6. Garmin 740s is the unit. I got depth graphs, temp graphs, frequency choice, time. location, and depth memory.

I boat in eastern North Carolina where the water is rarely deeper than 20 feet. Knowing the accuracy to the decimal place is very useful to my region.

Not saying in-hull is bad, almost did it, but transom-mount took out some guessing.

 

[yo]

I did also, works great and you don't cut another hole in the boat. used kids play clay , made a pocket and filled with water , place transducer in the water and read depth if you get a reading then redo with epoxy. good luck
mike

 

[IntervaleII]

Just to clarify, they make specific transducers to install inside the hull which work just as good as the though hull transducers

 

[Steve]

I installed mine a "shoot thru the hull" Humminbird puck in wax. the wax is from a wax ring as used to seal a toilet onto a floor drain, available at any hardware store. I kneaded the wax well to soften it and remove air bubbles, put a blob of it against the hull and squished the puck into it. It worked well so I left it there that was about 4 years ago. it has worked fine since. This is a digital display model.
Pictured below with the floorboard lifted

 

[RickB]

I installed mine a "shoot thru the hull" Humminbird puck in wax.

Love it! That's a keeper for the hints and tricks book. Thanks.

 

[psneeld]

use a baggie filled with water, place the ducer on top of it and find a suitable spot to shoot through the hull.

For my thru hull...I got a 3 inch PVC coupling, cut it to the hull angle, 5200ed it to the hull and filled it with water.

Then I drilled a hole for the stem of the ducer in a 3" PVC reducer and mounted it in the reducer, then stuck the assembly into the 3 inch coupling mounted to the hull. Looks as factory as any of the Airmar shoot through the hull cases.

2000 miles and 6 months later it still works flawlessly for about $10 in parts and goo.

 

[BruceK]

Garmin assured me I could run the flybridge GPS/Sounder off the lower helm one using a cable, with just one transducer so I bought. You can`t. I fitted the unit supplied transom mount transducer inside the hull, mounted in goop in a piece of pvc pipe cut at an angle so the top edge was level. I used a small level to ensure the transducer itself was level so it shot correctly straight down. It works, takes a few seconds to find bottom,then it`s fine. The IG hull is nearly 1" thick solid f/g.

 

[RickB]

For my thru hull...I got a 3 inch PVC coupling, cut it to the hull angle, 5200ed it to the hull and filled it with water.

That's how I mounted one in my Zodiac. Only have to remember to keep the water supply topped up though. And for the record, if the transducer or mount is off a few degrees it really doesn't matter. Unless you are doing hydrographic survey work the error is negligible and can be offset in any event.

I really like the wax idea, may use wax to replace the water.

 

[psneeld]

That's how I mounted one in my Zodiac. Only have to remember to keep the water supply topped up though. And for the record, if the transducer or mount is off a few degrees it really doesn't matter. Unless you are doing hydrographic survey work the error is negligible and can be offset in any event.

I really like the wax idea, may use wax to replace the water.

Wonder if you could melt it and set the ducer in just as it was starting to solidify (to help eliminate bubbles)?

 

[FF]

While a shoot thru the hull transducer does work , you can tell shallow water depths and find fish to eat , it has a problem.

The depth the unit will read to is reduced a good deal.

If you consider the depth gauge to be part of the navigation instruments loosing much of the depth will reduce your ability to run contour nav or similar.

GPS is great , but may not always be with us.

Belt and suspenders with on board gear might be prudent.

 

[RickB]

Quote from the major manufacturer of transducers:

[FONT=arial,helvetica,sans-serif]"All Airmar in-hull transducers are engineered to offset the signal-loss from passing through a fiberglass hull. Our in-hull transducers are far more sensitive than mounting a standard transducer inside your hull. And our in-hull models have built-in deadrise correction to aim the transducer's beam straight down toward the bottom. All Airmar in-hull models will perform as well or better than comparable transducers installed outside the hull. [/FONT]"

 

[Northern Spy]

True, but if you are mounting a thru hull or transom mounted transducer inside you will lose resolution and depth as it will be going through one or more mediums of different density. You will also see that on the top of the screen if you are using a fishfinder. Many of them have a means of filtering out the surface bounce though.

Real world experience was that the Garmin 400 series fishfinder with a 600w transom mount transducer was adequate to ~800 ft depth when mounted in the hull for bottom sensing, but the bottom clarity was low. When it was placed in the water (held on a stick over the side by hand, an experiment) the resolution increased greatly and the depth went to over 1000.

It would make a difference if you were game fishing, I guess.

When I hauled out, I replaced my temporarily mounted toilet ring beeswax transducer with a different thru hull transducer. I wanted a paddle wheel and temperature as well as the better bottom resolution at depth as I use it for setting prawn traps (rocky bottoms). The fish echos are smaller and more accurate as well.

If you just want a number, the wax mount will work just fine.

As Rick pointed out, the transducers made for in hull have a different acoustic window and would work as well as a thru hull.

 

[Datenight]

For my thru hull...I got a 3 inch PVC coupling, cut it to the hull angle, 5200ed it to the hull and filled it with water.

I used the same method and had no problems for 14 years with a Garmin 125 GPS/Sounder. Still going strong with the new owners. I glued a screw clean out to the top the 3" pipe and drilled a hole for the wire. Check the water level every spring. Was I to do it again though, I realy like the wax idea.

Rob

 

[BobH]

I guess a transom mounted transducer is there to confirm that you have just run aground?

Bob

 

[jwnall]

I have to say that this thread has given me some really useful hints!! Kind of a "Heloise's Hints For Boaters."

John

 

[CPseudonym]

I'm going to try a through hull transducer in wax on my boat. I've been having intermittent trouble with my screen blinking and freezing in shallow water.

After having steering issues yesterday that "self corrected" for no apparent reason I think it's narrowed down to grass mats near my cruising area and low tides. My only logical summation(as my blinking issue only happens in less than 7 feet of water) is the grass is interfering with my transducer in the shallows and making my sounder blink the last reading.

Hopefully the in hull transducer will end this annoyance. Fortunately our bottoms are soft mud.

 

[jwnall]

. I've been having intermittent trouble with my screen blinking and freezing in shallow water.
.

That would drive me around the bend! Guess it comes from having a sailboat for so long, but I'm paranoid about having a depth indicator that is 100% reliable. In fact, on the sailboat I had two of them (one primary, and one backup which I kept turned off).

John

 

[BobH]

Our boat came with a Hummingbird fishfinder. It is showing about 400+ feet sitting in the slip in the marina. It seems to be totally useless when you get below around 20 feet, about the time you really need it.

Tried all the tuning and tweaking but nothing has helped.

Bob

 

[jwnall]

Our boat came with a Hummingbird fishfinder. It is showing about 400+ feet sitting in the slip in the marina. It seems to be totally useless when you get below around 20 feet, about the time you really need it.

Tried all the tuning and tweaking but nothing has helped.

Bob

Um, perhaps you just have a deep slip??
.
Leaving the west end of Cuba, heading over to Isla Mujeres in Mexico, we hit about 12,000 feet. Very deep! My depth indicator just looked at me, and I could almost see it saying "You gotta be kidding!!"

 

[CPseudonym]

That would drive me around the bend!

Believe me, it has

I think I've found the problem and solution so I'm all better now

 

[jwnall]

Believe me, it has

I think I've found the problem and solution so I'm all better now

Share it. It may prove useful to one or more of us.

 

[CPseudonym]

A combination of having the unit on automatic range mode(per the manual) and the grass that grows in my local area. I believe the grass is getting stuck on my transducer or somehow causing interference that sends my sounder into stupid mode.

Post #5 of this thread and my steering issue that self corrected yesterday actually made me consider the transducer being interfered with. When I mount the new ducer inside the hull I'll report back.

 

[Ben]

I guess a transom mounted transducer is there to confirm that you have just run aground?

Bob

My full keel extends to the rudder and is the deepest part of my draft, so when I am showing 4.0 feet, I am about 3 inches from a "touch". Transom mount is adequate in this regard because we have shallow rises in NC. I also have my original thru-hull Humminbird unit which measures amidships, but it is 1995 vintage and shows whole numbers and not any decimals. It's precision and accuracy are not always reliable, but it does the job with periodic filling of the oil cavity.

 

[BruceK]

I'm going to try a through hull transducer in wax on my boat. I've been having intermittent trouble with my screen blinking and freezing in shallow water.

After having steering issues yesterday that "self corrected" for no apparent reason I think it's narrowed down to grass mats near my cruising area and low tides. My only logical summation(as my blinking issue only happens in less than 7 feet of water) is the grass is interfering with my transducer in the shallows and making my sounder blink the last reading.

Hopefully the in hull transducer will end this annoyance. Fortunately our bottoms are soft mud.

Craig, my transom mount transducer used as a thru hull,(it came with the unit), sits in clear silicone,see earlier post. Before fixing I tried it in a bag of water.
My thru hull transducer very occasionally, momentarily, loses its grip on the bottom and blinks until it finds it, I suspect the transducer face may be dirty/needing a/f.
I think transom mount transducers are for trailered boats.

 

[Peter B]

That's how I mounted one in my Zodiac. Only have to remember to keep the water supply topped up though. And for the record, if the transducer or mount is off a few degrees it really doesn't matter. Unless you are doing hydrographic survey work the error is negligible and can be offset in any event.

I really like the wax idea, may use wax to replace the water.

All the depth sounders I have installed have come with ones designed for transom mounting - not ideal in a large vessel in my opinion, so as there is always a 2 inch puddle of water in my forward enginroom bilge and they work in there so well I just left them there, one placed either side of the keel and set at different frequencies they don't interfere with each other at all. I've considered setting them in Sikaflex, epoxy or even the wax idea, and come to the conclusion I would gain nothing, so why bother.
I have them fixed in the correct orientation and so they don't move, but as Rick points out, it is not that critical.