Permanent Wet Transducer Installation
 

Today's project was to come up with a way to permanently install a new Fish Finder Transducer using the wet method. I would like to take credit for this idea but truth be told, I found a post from a guy in Australia who came up with this idea a year or two ago. I have modified the original installation a bit.

You will need a 3" piece of drain pipe or a 3" adapter, some sort of cap that will screw or clamp to the top of the adapter, some goop, a few stainless screws and a fish finder with transducer. I used a rubber cap a threaded 3" adapter. You could also use a threaded cap but I thought the rubber cap would provide a better water seal.

The first step is to attach the "well" to the hull of the kayak. I shaved the bottom of the adapter a bit to make it fit the contour of the hull and gooped it to the plastic making sure there would be no leaks once the well was filled with water.

Attachment 1794

Next came mounting the transducer to the cap. I sliced an X in the rubber that would expand large enough to allow the transducer plug to fit through. You could also drill a hole but that would mean a larger waterproof patch later. In the middle of the X I drilled a hole large enough for the cable to slide through without distorting the rubber.

Using the transom mount that came with the transducer, I attached the transducer to the inside of the cap making sure that everything would fit inside the well when the cap was installed. I marked the top of the cap to show the direction the front of the transducer was pointing and gooped the area where the cable passed through to make it water tight.

Attachment 1795

After the goop cured, I filled the well with water, slid the cap with transducer over the top and tightened the hose clamp. The completed installation is below.

Attachment 1796

If all goes according to plan, I should be able to fill the well with water once and forget about it. No more constantly checking the foam ring to make sure the water has not spilled, dried up or drained away. Since I store and transport my kayak upside down It is very important that this thing does not leak. We will see.

I have not yet tested this installation on the water but hope to go to La Jolla on New Years Day. If you see me out there, please feel free to paddle on over and check this installation out.

I have a couple concerns beyond whether this thing will remain water tight. Will the fact that there is about an inch of water between the transducer and the hull have any effect? Since the temperature sensor is inside the well, it will probably not give a very accurate reading. The water in the well will have to stabilize with the ocean water. That could take some time. It will almost certainly not be able to detect subtle changes in the water temperature as I peddle from one place to another. All things considered, this is not a very big deal.

See you out there.

Bob

Bob, you're Genius!

Just what I needed to replace the existing styro-well.
Now I have to find the bracket that came with the transducer.

How did you grind down the pvc to fit the curves?

Awesome!
 

So you keep the transducer itself clean of goop, glue, silicone etc. and if you have to drain it you can do so with a hand held manual bilge pump. The transducer does not come in contact with the hull. Are these assumptions correct?

Great job Bob. This will work perfect for those of us that have portables. Just unscrew the cap and your golden. Clean work and nice pictures too.

Thank you!

Nabeeko, I used a hand planer to shave the edges of the well but you could use just about anything. The contouring does not have to be exact because Goop is a very forgiving sealant.

Bentrod, all your assumptions are correct. One of the reasons I installed the transducer in the cap rather than to the well as our Aussie friend did was to allow for portability. For about $4 you could install a well in another kayak and you could move the FF around as needed.

I think that this is a good design but a better design could come from the kayak manufacturers themselves. Imagine a recessed area in the bottom of kayak with a hollow tube running through the hull to the deck, exiting some place that would be appropriate to mount a fish finder. Hobie could do it below the sail mast tube. The plastic in this area could be beefed up to allow mounting screws that would not puncture the hull. They could even design a cover plate that fit over this recessed area to make the bottom of the kayak smooth.

Now that would be cool.

Bob

P.S. I filled the well with water, tightened everything down and turned the kayak upside down so it could be strapped it to the roof if my truck getting ready for tomorrow's fishing trip. I checked for leaks after a couple of hours. Nada.

Now lets hope the thing will put me on some fish.

Bob

Bob, that looks super cool. I just got a fish finder recently and have been thinking about many different ways to install the transducer, and this tops them all. Thanks for the inspiration. Can't wait to hear how it works. Do you think it will still give accurate temperature readings?

The bottom of the hull eventually equals the temp of the water outside. The hull reads the air temp when you launch but 10-15 minutes on the water and mine is getting comparable readings to transducer in the water. It is more gradual, but not like we are looking for temp breaks. This is a great set up, been tying to figure a way to seal my wet mount.

Just got back from the maiden voyage with this setup. It worked perfectly. More later.

Bob

could you hear the pinging of the tx?
mine is loud as sh*t...

As I mentioned before, this setup worked perfectly. I could not hear anything from the sonar. In fact, I have not heard that this is a problem with any sonars in this class. Yakrider, you must have really good hearing.

There were no leaks from the well and my images were excellent. The fish finder is a new one with higher resolution than my previous unit so I cannot tell you if the improved images are a result of the better FF or the transducer setup.

As expected, the temperature readings were a little misleading for a while. I had the kayak on the top of my truck overnight where the outside temperature got down to the low 40s. When I started to peddle out, the FF said the temperature was 44 degrees. I knew that was wrong as I passed a group of swimmers heading out from the Cove. It took about an hour for the water in the well to warm to the temperature of the ocean. If having accurate temperature readings is important to you, this type of installation my not be the best choice.

If portability and ease of installation are what you are looking for, this is definitely the way to go. Now that I know what to do, I could probably reproduce this installation in about ten minutes.

Bob

Great idea! My wet well install has worked perfectly for over a year, but this is much better! No more filling it with water or forgetting to... Thanks for sharing!

Thats a neat setup. I was thinking of changin to a wet install. This will help alot.
Thanks.

Wet or not to wet?
 

I just read some guy used plumbers putty and stuck it inside the hull without a reservoir...

Does it have to be wet? Is there a sensor further up on the transducer that has to detect water? If you seal the transducer (I know you didn't Bob) with putty, glue etc. to the hull then water wouldn't touch the bottom of the transducer anyway...

Plumbers putty would be too weak of a sealant. Goop is much better. It will withstand anything you throw at it.

With my setup, the transducer is suspended in water above the hull. You have to have some solid or liquid connection between the transducer and the ocean. If there is an air gap, the thing will not work.

Bob

Brilliant! Great job!

Ive heard that Surgilube makes for a great medium and has anti-bacterial stuff that prevents algae and mold build up. Its the same stuff they use on ultrasounds. At 2 bucks for 4oz at your local pharmacy, seems like a good deal.

If you drill in an injection port, later sealed with a screw, you can fill up that reservoir real good.

/bing

Wahoo, in my installation, the transducer was suspended about an inch above the hull. I am not sure if it makes any difference whether there is contact with the hull or not. All I can say is that what I did seems to work fine.

As for installing near the transom, that would probably be fine except that your FF will be showing you stuff you have already passed over rather than what you are just about to reach. With inexpensive FF like the one I use, it probably does not make much difference as the resolution is not good enough to see much more than the bottom contour and to find bait balls.

Someone with experience using a high-end fish finder could probably be more helpful than I on this subject.

Bob

Bob,

Great idea, and I am going to re-install my transducer with your method this weekend..Quick question (now that I have read the whole thread). How much space between the hull and the transducer do require? That will determine I guess, the length of PVC needed??? Also, why not mount this at the rear of the yak as they do in boats. The Revo has an access hatch that would make the install easy...I think?

Roger

I am not sure if mounting the FF in the stern will effect the performance in a significant way but if you have a Revo, there may be a good reason to mount there. The space in rear hatch on the Revo is not easily accessible while on the water and therefore the real estate is less valuable, at least to me. Having the transducer mounted there would save some storage space up front.

I store my FF battery in the otherwise mostly useless tray that came with my Revo. The stern is usually dryer than the bow and therefore probably a good place for electrical stuff to live.

Give it a try.

Bob

Attachment 1811

WOW!!!!
 

That's some sick shit!!:D

Very nice work, Bob. I never seriously considered using a wet mount until seeing this. I always thought they were more trouble than they were worth. This has changed my mind. I'm getting a new Stealth in a couple of weeks and I'm going to use your idea.

what are the benifits of haveing a wet mount transducer also what are the draw backs.