Installing a depth sounder and fish finder.

[coopec43]

Some time ago I bought an Eagle Cuda fish finder and much more recently I was given a Navman Depth Sounder.

I have always been a bit apprehensive about fitting them as I most certainly didn't want to start cutting holes in the hull to fit the sensors. And I wondered whether they would have the power to work through an inch of solid fiberglass.

I read the directions carefully for fitting the sensors inside the hull then made up a couple of cupfulls of epoxy/talc bog. I then covered the underside of the sensors with the bog ensuring there were no bubbles, then held the sensor firmly against the hull and tapered more bog from hull to the sensor.

I left both for a couple of days to cure then tested the Navman and the Eagle and both worked! AND what is more they gave the same result - Navman 3 meters, Eagle 9ft. Since Helen was in her pen I think 3 meters would be just about spot on.

[Spot]

Congrats on the successful installs. I did not know epoxy and talc would work. I have one to install on a thinner hull, assumed I would need silicone, and do not want to mess with the fluid options like antifreeze.

[coopec43]

I don't think there is anything magic about epoxy/talc. I would have been quite happy to use polyester/talc. (I've always used epoxy/talc to glue things together)

These are the directions I followed PAGE 18/19

https://www.manualslib.com/manual/41...page=22#manual

Maybe I am wrong but I wouldn't use silicone as I think it would be a bit too "spongy". I wouldn't want to use anything that could absorb the sensor "echo"

Here is another thread which could help.

https://www.thehulltruth.com/boating-forum/140529-best-epoxy-transducer-mount.html

[JBP]

Originally Posted by Spot

Congrats on the successful installs. I did not know epoxy and talc would work. I have one to install on a thinner hull, assumed I would need silicone, and do not want to mess with the fluid options like antifreeze.

You can use a variety of things. Butyl tape will work and is good for testing. Electricians putty available at any hardware store will also work. Epoxy, with or without filler is a permanent solution, though I'd use silica rather than talc. Talc can absorb water, though it's not a big deal encased in epoxy.

[Moana Bella]

Our through hull sounder was installed by a professional, and he stuck the frame down with silicone, then filled the well with the propylene glycol. Within about 3-4 months the unit was sliding around and not giving us a good reading. It looks like the glycol ate the silicone.
So next we stuck it down with epoxy and re-filled the well with glycol. Works great now.

[coopec43]

Originally Posted by JBP

You can use a variety of things. Butyl tape will work and is good for testing. Electricians putty available at any hardware store will also work. Epoxy, with or without filler is a permanent solution, though I'd use silica rather than talc. Talc can absorb water, though it's not a big deal encased in epoxy.

"Butyl tape will work and is good for testing"
OK it may work...... temporarily for testing.

Butyl tape would be just temporary - certainly not permanent . All air must be eliminated from the bedding as the sensor will not work through air

Can you give me a siource of your information?

[coopec43]

Originally Posted by Spot

Congrats on the successful installs. I did not know epoxy and talc would work. I have one to install on a thinner hull, assumed I would need silicone, and do not want to mess with the fluid options like antifreeze.

Talc is commonly used to thicken epoxy resin, paints.

Description. Talc is a soft, non-abrasive inert mineral powder that acts as a functional filler in paint, thermoplastics, rubber and adhesives.
$5.00 to $50.00 · ‎ In stock
https://trojanfibreglass.com.au/product/talc-powder/

https://www.boatpaintstuff.com/sites...ation-text.pdf

https://forum.woodenboat.com/forum/t...keners-fillers

[Spot]

Thanks for the tips. I am about three months away from trying anything, still too cold.
Polyester and talc= Bondo body filler, yes?

My sensor is on an older, multi-mode fish finder so it might like being in the water better than being in the hull.

[wyb2]

Originally Posted by Spot

Thanks for the tips. I am about three months away from trying anything, still too cold.
Polyester and talc= Bondo body filler, yes?

My sensor is on an older, multi-mode fish finder so it might like being in the water better than being in the hull.

According to the can in my garage.

[Shanachie]

Buy a wax toilet bowl ring at Home Depot. Pull off a piece, squish it around and set it on a flat part of the hull after wiping it with acetone.



Set the transducer flat in the wax. It will never move and the transducer will work perfectly.


The beauty of this is that it is reliable but not permanent, like epoxy.

[coopec43]

Originally Posted by Shanachie

Buy a wax toilet bowl ring at Home Depot. Pull off a piece, squish it around and set it on a flat part of the hull after wiping it with acetone.

Set the transducer flat in the wax. It will never move and the transducer will work perfectly.

The beauty of this is that it is reliable but not permanent, like epoxy.

Epoxy is mot permanent! It can be removed easily if you have the right tools. That is the least of your worries!

FOR EXAMPLE
The Sealant Cutter is a multi-tool blade for fast, efficient and thorough removal of silicone, epoxy, glue, sealants and more. A 3-edged knife blade that is very convenient to have when you need to remove silicone sealant in the bathroom or other places.

https://www.oslotoolcompany.com/prod...l-blade-5-pack

[wyb2]

Originally Posted by Shanachie

Buy a wax toilet bowl ring at Home Depot. Pull off a piece, squish it around and set it on a flat part of the hull after wiping it with acetone.



Set the transducer flat in the wax. It will never move and the transducer will work perfectly.


The beauty of this is that it is reliable but not permanent, like epoxy.

This method seems highly recommended. The PO of my current boat did it, and it caused a minor headache for me.

It’s true that it’s not permanent, but if you want to move/remove the transducer, that wax is a bear to clean off the rough surface of unfinished fiberglass. And that hard to clean wax means you will have a hard time bonding anything to that area in the future (except more wax I suppose). Also the exposed wax around the perimeter of the transducer was a magnet for dirt/dust/grime.

[wyb2]

Originally Posted by coopec43

Epoxy is mot permanent! It can be removed easily if you have the right tools. That is the least of your worries!

FOR EXAMPLE
The Sealant Cutter is a multi-tool blade for fast, efficient and thorough removal of silicone, epoxy, glue, sealants and more. A 3-edged knife blade that is very convenient to have when you need to remove silicone sealant in the bathroom or other places.

https://www.oslotoolcompany.com/prod...l-blade-5-pack

Well to be fair, nothing is permanent if you have the right tools

That smooth blade might be good for silicone and other soft caulk/sealants, but a regular toothed blade will do much better on hard epoxy or polyester.

[Shanachie]

Originally Posted by wyb2

This method seems highly recommended. The PO of my current boat did it, and it caused a minor headache for me.

It’s true that it’s not permanent, but if you want to move/remove the transducer, that wax is a bear to clean off the rough surface of unfinished fiberglass. And that hard to clean wax means you will have a hard time bonding anything to that area in the future (except more wax I suppose). Also the exposed wax around the perimeter of the transducer was a magnet for dirt/dust/grime.

Why would you want to move the transducer? There usually are a limited number of spaces on a hull where you can place a transducer due to the curve of the hull. Pick well and stick with it.


In my experience, acetone cleans up most anything. Something as simple as wax should be no problem at all. Even dish detergent should do the job reasonably well. It will take wax off your boat or car.

[coopec43]

Originally Posted by wyb2

Well to be fair, nothing is permanent if you have the right tools

That smooth blade might be good for silicone and other soft caulk/sealants, but a regular toothed blade will do much better on hard epoxy or polyester.

I won't argue with that!

But there are so many different multi tool blades.