Transducer mounts & performance

Y'all may remember I have tried all the transducer mounts ever mentioned in these forums for my H'bird FF/GPS.

Direct in-the-water wand
Through the scupper
Foam block with water
Foam block with grease
Duct seal (plumber's putty) pancake
Duct seal ring with water

The direct in-the-water wand and the through-the scupper mounts were on my T13A and the transducer performance was perfect. 

The inside-the-hull foam block with water gave great performance also, but I got tired of refreshing the water.

So, I filled the foam block with trailer wheel bearing grease and mounted the transducer in that and also got great performance for almost 2 years. 

Then, ... I started getting weak returns.  Returns with periodic spikes.  Horrid returns in water less than 25 feet deep.  I had to turn up the sensitivity to the maximum.  If I pulled the transducer out of the in-the-hull mount and held it in the water I got good performance - sometimes. 

I pulled out the foam block, scraped and cleaned the hull and made a thin pancake of the sticky duct seal and pressed the transducer into the pancake.  The results were mixed - sometimes good sometimes not.

Then I pulled out the putty pancake and replaced it with a ring of putty filled with water.  The transducer was held in place by squeezing the ring into contact with the transducer.   Mixed results.

Frustration cased me to go back to the beginning and I installed another foam block with water.  Mixed results.

So, I ordered a new transducer.  Installed it into the now new foam block and water.  Perfect performance.  Strong returns.  No spiking.  No fall off in shallow water.  I could follow my lead head in its drop to the bottom and as it glided over the bottom. 

It appears my transom transducer lasted about 3 years.  I do not know if the grease seeped past the seal on the thermocouple button and contaminated the inside.  Hard to imagine as these things are supposed to take a beating.  But, grease is not water. 

This is what I learned.  If I had to start over and was mounting a transducer on the inside of the hull, I'd start with a Duct Seal pancake.  No Goop, no glue, no water filling, make the pancake and install the transducer in about 5 minutes.  Completely removable, repeatable, and transferable between kayaks.  The only potential issue is that the Duct Seal has a certain amount of oil content.  Like the grease mount, it may seep past the thermocouple button.  Smearing the button with a thin layer of Goop may ameliorate the issue.

Here is a screen shot of fish and kelp off Rosario.  The FISH ID function had stopped working when my transducer woes started so I was running with FISH ID on and I think with maximum sensitivity.  I generally only use FISH ID when fishing around kelp and big dense bait balls.  In the past I have routinely used 50% sensitivity.

Compare this screen shot with those in this previous thread: http://www.northwestkayakanglers.com/index.php?topic=7639.msg84506#msg84506

Thanks for sharing. Did you ever just use goop?

I tried using grease and think that it does eventually get through where the thermocouple sticks out. Lost my temperature sensor after about a year so would not recommend using grease.

just curious.. if the "through the scupper" worked perfect, why are you still using other methods that are less efficient?

OK, scuse my ignorance but what is a duct seal ring?  Guess I could ask the guy at home depot.

Thanks for sharing. Did you ever just use goop?

No.  So, maybe I didn't try EVERY method mentioned in this forum.

I tried using grease and think that it does eventually get through where the thermocouple sticks out. Lost my temperature sensor after about a year so would not recommend using grease.

Interesting.  I never lost my temperature sensor. 

just curious.. if the "through the scupper" worked perfect, why are you still using other methods that are less efficient?

Different boat.  Thru-the-scupper was on a T13 with the scupper mount.  Then I got a Revo.

OK, scuse my ignorance but what is a duct seal ring?  Guess I could ask the guy at home depot.

Make a ring with Duct Seal.  Stick it on the inside of the bottom of your hull.  Fill with water.  Place transducer inside ring.  Squeeze edges of ring around transducer.  See the old thread referenced in my OP.

I went with the rigid insulation, foam block installation. Since I am cheep and move my fishfinder from one boat to another. The Rigid foam and Marine silicone glue works well for about one year. I then have to take the foam off and re-glue.  I do have to admit that the water part is a hassle. I forget to fill it with water at least 50% of the time.

Wobbler

What are the drawbacks of mounting through the scupper hole?  Seems to be pretty quick, clean and easy.

What are the drawbacks of mounting through the scupper hole?  Seems to be pretty quick, clean and easy.

There is no downside to mounting through the made-for-a-transducer scupper hole like on the Trident 13.  I have two boats, a T13, and a Revo13 (no made-for-a-transducer scupper). 

The T13 scupper mount leaves the transducer flush to the bottom of the hull.  At first I was reticent about dragging the boat thinking I could damage the transducer, but the transducer is MUCH, MUCH tougher than the kayak hull.  Anything you are willing to drag your boat across will damage the hull plastic before it damages the transducer plastic.

I don't get what makes adding a few tablespoons of water to the foam puck so difficult before each launch? 
It takes longer to get the silly seat buckled into place.   

If it's the "adding" of the water itself that is hard to do, maybe try a few different methods of adding said water. 

I've tried all the below methods in this order.

-Drinking water bottle.




-Small cup about the size of Dixey.




-Sponge.




-Spongee towel.




-Plastic syringe.




-Plastic syringe with tube extention.  (Note: This is not a picture of the one I actually use)





The plastic syringe is my go to method as of now and is stored in my battery dry bag.
The tube comes off and is stored next to the syringe handle in the body of the syringe.
No mess, no fuss!

+1 to what Insayn stated. I had a different Dixie cup though.
With a snug fitting and well adhered closed cell , flexible foam puck, in two different yaks, I have gone two and a half weeks without adding water.
May be able to go longer. Just haven't tried

+1 to what Insayn stated. I had a different Dixie cup though.
With a snug fitting and well adhered closed cell , flexible foam puck, in two different yaks, I have gone two and a half weeks without adding water.
May be able to go longer. Just haven't tried

Mine only holds the water when the kayak is in the factory upright position. 

I purposely slotted the rear section of the puck to allow air bubbles to quickly slip past and escape from below the ducer.
That, and I remove my ducer along with the entire sonar/battery setup into a dry bag before loading the kayak up to go home.
Water just lands inside the kayak and dries out on it's own.