Permanent Wet Transducer Installation - Kayak Fishing Adventures on Big Water’s Edge

dsafety · 12-31-2009, 01:06 PM

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.

Well-with-water.jpg

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.

Transducer-Installed.jpg

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.

Completed-Install.jpg

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

nabeeko · 12-31-2009, 01:35 PM

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?

bentrod1 · 12-31-2009, 01:49 PM

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!

dsafety · 12-31-2009, 02:17 PM

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

dmrides · 01-01-2010, 07:32 AM

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?

Iceman · 01-01-2010, 07:41 AM

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.

tattuna · 02-22-2010, 03:41 PM

Quote:

Originally Posted by dsafety

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

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?

dsafety · 02-22-2010, 04:07 PM

Quote:

Originally Posted by tattuna

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?

That is exactly what I did. I screwed the mount to the rubber from the inside and then sealed everything with Goop.

Bob

Geoffkoop · 02-23-2010, 09:26 AM

Well im almost done with the wet mount setup. Just waiting another day for all the Goop to dry. I have an Eagle/Lowrance FF so i had to go with the 4in pipe as well. It looks like it will work well though and is fairly simple to construct. Ill let you all know when i test it out.

dtownfan · 02-24-2010, 04:03 PM

dsafety.......i took my hummingbird kayak mount out of the original packaging and fiddled around with it for about 25 minutes and decided to go with a wet mount version very similar to your post. hummingbird's mount just didn't look like the velcro zip-tie they include (to hold the tranny in the cradle of grease) would keep it stable enough for me. so....i made a trip to lowes and have a sweet set-up thanks to your pics and explanations. anyway, before i GOOP her up..........did you do anything to the flex-ible cap? like wipe it with rubbing alcohol or rough it up before applying the GOOP?

dtownfan · 02-24-2010, 06:18 PM

here are some pics i took after following bob's ideas. thanks again bob! i used a 3 to 4 inch adapter that had a smooth surface (smooth surface where the cap slides on). the 4 inch cap slides on and off easily (just a little space around the cap.....i used a screw driver at lowes to make sure it would tighten down well without distorting the rubber cap and potentially causing leaks or other problems) and with a few cranks of the hose clamp she is/was very snug. there is tons of material on top of the rubber cap for screws or bolts. i used 2 stainless steel bolts with nylon nuts. getting the hummingbird tranny cable through took an extra pair of hands and a flat head screw driver. if you drill a hole for the cable wire and cut the X as bob stated (or a T....i went with a T cut to stay away from the bolts i used) , you can use the screw driver to push on one of the individual triangles and pop her threw. i also drilled a hole in the tranny mount to help the cable wire feed up through the rubber cap near the bolts without being bound or making extra GOOPING. when the cap is on the distance between the bottom of the tranny and the potential surface of the hull has to be an inch or less. again, i looked over bob's work carefully and used as many hints as i could. i have yet to GOOP her up.

I was wondering if anything needed to be done to the cap before GOOPING. like cleaning or roughin up the surface. never sanded this type of material before. any suggestions.

thanks for all the posts! they are VERY helpful!

dsafety · 02-25-2010, 08:53 AM

Quote:

Originally Posted by dtownfan

dsafety.......i took my hummingbird kayak mount out of the original packaging and fiddled around with it for about 25 minutes and decided to go with a wet mount version very similar to your post. hummingbird's mount just didn't look like the velcro zip-tie they include (to hold the tranny in the cradle of grease) would keep it stable enough for me. so....i made a trip to lowes and have a sweet set-up thanks to your pics and explanations. anyway, before i GOOP her up..........did you do anything to the flex-ible cap? like wipe it with rubbing alcohol or rough it up before applying the GOOP?

I did not do anything to the cap but wiping with alcohol would probably be a good idea.

Bob

bigbarrels · 06-30-2010, 09:37 PM

How much water does the transducer have to sit in? Does Ultrasound gel work?

Geoffkoop · 07-01-2010, 08:22 AM

I have noticed a slightly better image compared to goop. My depth with goop seemed to be inconsistant (ex. 100 feet deep then all the sudden 190 feet, then back) . The wet mount has been better.

dsafety · 01-07-2010, 07:31 AM

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

12-31-2009, 01:06 PM	#1
dsafety Olivenhain Bob Join Date: May 2008 Location: Olivenhain, CA Posts: 1,121	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. Well-with-water.jpg 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. Transducer-Installed.jpg 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. Completed-Install.jpg 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

12-31-2009, 01:49 PM	#3
bentrod1 Member Join Date: Sep 2009 Location: Upland Posts: 60	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!

01-01-2010, 07:41 AM	#6
Iceman Administrator Join Date: Mar 2005 Location: 1-2 miles off the point Posts: 6,943	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. __________________

06-30-2010, 09:37 PM	#13
bigbarrels Senior Member Join Date: Aug 2008 Location: Vista Posts: 1,111	Amount of Water How much water does the transducer have to sit in? Does Ultrasound gel work?

12-31-2009, 01:35 PM	#2
nabeeko Member Join Date: Aug 2008 Posts: 68	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?

12-31-2009, 02:17 PM	#4
dsafety Olivenhain Bob Join Date: May 2008 Location: Olivenhain, CA Posts: 1,121	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

01-01-2010, 07:32 AM	#5
dmrides Senior Member Join Date: Aug 2009 Location: Point Loma Posts: 584	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?

02-23-2010, 09:26 AM	#9
Geoffkoop Member Join Date: Dec 2008 Location: So. Orange County Posts: 302	Well im almost done with the wet mount setup. Just waiting another day for all the Goop to dry. I have an Eagle/Lowrance FF so i had to go with the 4in pipe as well. It looks like it will work well though and is fairly simple to construct. Ill let you all know when i test it out.

02-24-2010, 04:03 PM	#10
dtownfan Member Join Date: Jan 2010 Location: Northern Virginia Posts: 50	dsafety.......i took my hummingbird kayak mount out of the original packaging and fiddled around with it for about 25 minutes and decided to go with a wet mount version very similar to your post. hummingbird's mount just didn't look like the velcro zip-tie they include (to hold the tranny in the cradle of grease) would keep it stable enough for me. so....i made a trip to lowes and have a sweet set-up thanks to your pics and explanations. anyway, before i GOOP her up..........did you do anything to the flex-ible cap? like wipe it with rubbing alcohol or rough it up before applying the GOOP?

07-01-2010, 08:22 AM	#14
Geoffkoop Member Join Date: Dec 2008 Location: So. Orange County Posts: 302	I have noticed a slightly better image compared to goop. My depth with goop seemed to be inconsistant (ex. 100 feet deep then all the sudden 190 feet, then back) . The wet mount has been better.

01-07-2010, 07:31 AM	#15
dsafety Olivenhain Bob Join Date: May 2008 Location: Olivenhain, CA Posts: 1,121	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