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.

Cali,

Others might be able to answer this question better than I but the main reason I went this route was that when I pulled up my old transducer I found that the goop that had attached it to the hull was full of bubbles. I was never very happy with the performance of my previous FF and have been told that it is important that no bubbles form in the goop as they are likely to cause poor performance.

I have also learned that the most efficient transmitter of sonar signals is water and that for best performance a transducer should be mounted in the water. For some strange reason the hull of a boat does not seem to cause any transmission problems so mounting the transducer in a pool of water inside the hull works very well. This is probably because the density of the hull is fairly close to the density of water.

Anyway, many of the guys who really know what they are doing have gone to the "wet mount" over goop. The problem with the installation method that most have employed up to now is that with the foam version of the wet mount, the water can leak away causing the transducer to perform poorly. I have seen guys on the water having to open their hatch from time to time to add water to the foam well. I wanted to avoid having to worry about this.

My version solves the leakage problem as the whole unit is sealed so the water cannot leak or evaporate. As a bonus, since the transducer is mounted in the rubber cap, it is easily portable to another location making it possible for one FF to be used on multiple boats.

Give it a try. The installation is easy and the materials cost only a few dollars.

Bob

Looks like a great setup! I've always preferred my wet mount over goop, but filling up the reservoir (or as crabkracker said, forgetting to) is a pain. I haven't had any leaks, but I noticed after about 2 years the pool noodle foam is degrading a little bit and the transducer slips out when I'm driving with the yak upside down. This setup should fix both those problems. This install is going to be my project for tomorrow! Thanks for the info!

Wet Trans...
 

Bob,

I just finished my install of the wet transducer (copied yours). Unfortunately, with the Lowrance transducer, you need to use the ABS 4in male adapter vs. 3in adapter. This sucks because one; its quiet a bit larger, and secondly, the 3 in. cap is flexible while the 4in cap is rigid...(sounds kind of West Hollywood-ish).

My only issue is going to be removing the cap to check for water levels. I am afraid I might eventually separate the ABS adapter from the hull since the cap is so rigid and difficult to remove. Also, last question. Did you sanitize the GOOP in the interior of the adapter (seepage) or do you think it matters? I am guessing with all glue and adhesives, as they dry air bubbles appear......what do ya think???

Anyway, thanks for you expertise!

You could make a small inspection hole in the cap and seal it with a rubber plug. That would allow you to clamp down the cap and never have to worry about removing it.

Thanks...I think I might give the inspection plug a shot.....Any recommendations on how to clean the GOOP of my transducer? What a royal pain in the ass......I am tempted to just go buy another one!

that is slicker than shit. I have the scupper transducer in my trident, but have two other kayaks where that would totally be perfect. and the portable part of it is way cool. yes, there is a better mousetrap :you_rock::you_rock::you_rock:

Wahoo,

I don't think having a rigid or rubber cap makes much of a difference. Most of the rigid ones are threaded so you could end up with some fairly twisted cables unless you pre-twist the opposite way before you put the cap on. Just make sure the transponder is pointed the right direction when you have things tightened down.

I think a rubber cap with hose clamp is a better way to go. You cannot secure a non-threaded rigid cap with a hose clamp the way you can with rubber. You should be able to find a larger rubber cap somewhere.

The inspection plug is a good idea. I had a problem with my FF last time out and thought that the water may have run dry. In ended up having to loosen the hose clamp while on the water to remove the cap to check things out, (it was a PITA). I discovered that there was still plenty of water, however. After putting everything back together, the FF worked fine. Maybe it was just a glitch in the unit.

I think I will add a fill hole to my setup so I can more easily add water if it is needed at some point.

As for cleaning the goop off, I don't have any recommendations. It probably is not necessary to get it all off. You just need to carve away any areas that have bubbles. Is there a solvent for Goop?

Bob

If mounted inside a hull, why does it matter which way the transducer is pointed? If mounted through hull, I can see that it would in order to avoid cavitation (bubbles) while the boat is moving.

Bob, the 4in. is a rubber cap and does come with the hose clamp, but it is the thickness of the cap and rigidity that worries me. I bought the 3in before I realized my Lowrance transducer was larger than the Hummingbird. The 3in cap is much more flexible.

PescadorePete,

The sonar transponder is directional. If you have the transponder pointing to the stern, your fish finder will show you things you have already passed so what shows up on your screen as you move forward would be what you would have seen if you moved backward had the transducer been aligned correctly.

If all you are using your FF for is to tell the depth of the water, this is probably not a big deal but if you are using it to actually locate fish or bait, you could be making decisions based on reading the data incorrectly.

Wahoo,

I don't think a thicker rubber cap is any big deal. It may make it harder to spread open the hole to get your plug through the rubber but if that is the case, just make the X cuts longer. You will be sealing these cuts with goop later anyway.

If you simply cannot spread the rubber wide enough, just drill a suitable sized hole in the rubber. Thread your plug through the hole and attach the transducer. Tape one side of the cap and fill the former hole with goop making sure you have some overlap on cap. When the goop has cured, go to the other side of the cap and spread a bit more goop there so the "plug you just made will not pop out.

The thicker rubber might actually make it easier to mount the transducer with screws since there will be more material for the screws to grab on to.

When you have completed your installation please post a photo for everyone to see.

Bob

can the transducer still read through the abs matirial, Of course it sends a signal down then the signal spreads out untill it hits the bottom of the ocean. will this matirial mess up any readings because of how dense the matirial is.

The only problem I have is mounting the transducer to the cap, but I am sure I can figure it out, I have a question how close can you let the transducer get to the hull of the kayak with this type of install

Pm me if you have the answer

I use a similar system that is a little more simple and works well. I have a small hard plastic box that is directly gooped to the inside of the kayak. The box is big enough for the transducer to sit in and the sides are 3" high. The bottom of the box was not removed so leaks are not a problem. I place the transducer in the box and add 1-2" of water and its good to go. I do not use a lid and water splashing out has never been a problem. You do not need much water. The depth finder I use is a Garmin and the picture is great.

dsafety...........i keep looking over your wet mount install and second guessing my future attempt at rigging my hummingbird. as of right now i have the hummingbird kit (sitting on the shelf) that craddles the tranny in marine grease. i pick up my yak next weekend and wonder......what will i do. i see the ease of moving the unit to other kayaks (i will only have one option there though) but if the sonar readings are better in water than grease well.....(would the grease make the hummingbird kit a wet mount?) i wonder how well the grease will do upside down if i ever have to store or transport that way.

are you still havin good results from the wet mount?

sorry to bring all this back up - just curious to learn more from your experience. any advice of things you would keep the same/change would be sweet!

I have no experience with the "grease mount" so I cannot help you there. I can tell you that my unit, along with my kayak has been stored upside down for weeks and transported the same way. There have been no leaks and the performance has been excellent, (except for a flaky problem common to many Humminbirds when they suddenly stop showing any depth readings for a while).

My guess is that you could use grease instead of water in my design and everything would work fine. On a really hot day, the grease could liquify and cause some problems, especially if you stored or transported your yak upside down.

I like this design because it is so easy to install and there is virtually no chance of screwing anything up as you can with a goop or epoxy installation. The portability is is nice feature as well.

I hope this helps.

Bob

Hey Bob (or anybody else that has tried this application) ,

So I did both my Trident and my wife's Tarpon. I finished the install, everything looked great. Both held water with no leaks, UNTIL I went to load my Trident on the truck. I was strapping it down when I heard a "glug-glug-glug" ... all the water was coming out. When my boat flexed, it compromised the goop. I since went back to my wife's boat and put a little side-to-side pressure on the pvc and hers lifted from the bottom as well. I'm thinking I need to rough up the bottom before the goop application.

Any ideas??

How do I get around this problem?

Thanks,
Rob

Winner winner chicken dinner:cheers1:

Most kayak surfaces retain a little silicon, which is used as a mold release agent. Goop sticks very well to most clean surfaces so need to give the area you plan to apply the Goop to a good cleaning first. Alcohol works great. So does a light sanding of the area. You can do both.

If you properly prepare the area, Goop will stick so well that it is nearly impossible to remove.

Bob

my question is if u set the transducer to high in the water do u inturn reduce the size of the sonar ping due to the constriction of the tubing it sits in hmmmm???

A side imaging or wide angle transducer probably won't work well in a wet well, but they don't work well for any in-hull application. The dual frequency transducers have a narrow and a wide cone angle. Even at a 60 degree cone angle, the transducer would have to be pretty far off the bottom of the yak to lose performance. The narrow cone would probably work in any conceivable kayak wet mount. Whatever return you would lose will be from the outer part of the cone. You should still get decent, if somewhat attenuated return.

How did you attach the transom mount to the inside of the rubber cap? I'm trying this right now and that's the one part I can't figure out. Looks like you used screws?