Mounting a depth finder transducer

Beady · Post by **Beady** » Tue Feb 22, 2011 2:08 pm

I got a Hummingbird fish finder for Christmas and am starting to think about installation on my C-22. I was going to mount the transducer on the stern but a friend suggested that I mount it inside the hull in a bunch of silicon. My questions is has anyone done this and if so where did you mount the transducer? In addition to the depth finder I also wanted to be able to use it to fish with so do all the functions work (bottom profiles etc.) I do realize that the temp. sensor will be off slightly. Have you ever had problems with the center board down blocking a section of the signal?

Suggestions would be great the device is a Hummingbird 728 and there is an additional gps antenna so it doubles as a chart plotter. Christmas day I did put the transducer in a bucket and it did tell me that it was about a foot deep, no fish in the bucket. LOL.

CaptainScott · Post by **CaptainScott** » Tue Feb 22, 2011 2:37 pm

OK, remember, when mounting the transducer what they measure is AIR! So if you have ANY air pockets in the silicone your transducer will not work!

However an easy fix came up on the forum. I forgot who brought it up. Maybe Billy?

All the transducer needs is to sit in water. So a leaky bilge really helps! LOL! Oh, wait, we don't want leaky bilges so fix that leak! Instead get a 4 inch ABS pipe cap with a threaded lid. Silicone the cap to the lowest flatest point under one of your sette's. Drill a hole for the wire for your transducer. Fill the now mounted ABS cap with water and set your transducer into the water! There ya go! A perfect system! put the cap on to avoid the water spilling ot on excellent sailing days!

I have not done mine yet but I have bought all the parts and will install them soon! I also have fish finder from West Marine. It was on sale cheap for around 80 or 90 bucks! They work great!

Hopefully the original poster will have some photos for you here soon!

Scott

Windward · Post by **Windward** » Tue Feb 22, 2011 5:56 pm

Windward's is fitted under the head area. I cut a chunk of PVC pipe at an angle that matched the hull, leaving the top basically level. After washing, sanding and cleaning the surface, I hot glued the pipe in place, with an extra fillet of duct tape around the exterior joint. I mixed up some quick-set epoxy, being careful to avoid bubbles, then poured the epoxy in -- self leveling!

As the epoxy kicked, I wired up the transducer so that I could test it once I had it in place but before the epoxy kicked.

Once the initial pour had kicked but wasn't fully set, I made a fresh batch, painted the bottom of the transducer and the top of the previous pour, then firmly pressed the transducer in and taped it in place. A quick test showed that all was well, so I left it to cure.

That was about 5 or 6 years ago. The display unit died and had to be replaced, but zero problems with the transducer.

mcrandall · Post by **mcrandall** » Tue Feb 22, 2011 6:20 pm

This is new to me,never had a fish finder--are you saying the transducer works through the hull?

mcrandall · Post by **mcrandall** » Tue Feb 22, 2011 7:35 pm

OK, scratch that last question. Did some research and now understand.

First edit: Also just figured out that I can't delete that last post cuz I just posted this one. My, my...what a night of learning!

Holiday · Post by **Holiday** » Wed Feb 23, 2011 5:59 am

I would suggest you check with the folks at Humminbird also. I have found them very helpful and they used to have a transducer trade in policy that allows you to send back the trasducer that came with the unit and get the best match for the boat. I used and angled puck tranducer epoxied in place on my Ensign. They can also advise on setting the transducer in place so that the keel does not interfer with the coverage.

If you want to try out a spot before you glue anything down you can put the transducer in a ziplock freezer bag full of water and try different spots on the hull. It helps to we t the hull uner the bag.

sailbob2 · Post by **sailbob2** » Mon Feb 28, 2011 5:04 pm

I installed a Humminbird Fish finder (Tri-Beam) on CRYSTA. I just bedded it in silicone near the orginal thru-hull in the bow storage area located under the v-berth - ran the wiring out to the cockpit and mounted the display to my steering pedistal. No problems, very accurate and works wonderful did not use the temp feature. I use it for depth sounding as well as fishing for perch and walleye here on Saginaw Bay, Michigan.

Bhacurly · Post by **Bhacurly** » Tue Mar 15, 2011 12:14 pm

Hey Sorry for the late response,

Back from Maui, work, and the site being down,,,,

Check the original post I put up:

http://www.chryslersailors.com/discussi ... ight=billy

It has worked well for me for 2 seasons now...

mariner · Post by **mariner** » Tue Mar 15, 2011 3:49 pm

There was a great article in some magazine about mounting a fish finder in a sailboat. If anyone wants a copy pm me and I'll dig it up for you.

Beady · Post by **Beady** » Wed Mar 16, 2011 5:23 am

Got the pictures thanks

excavman · Post by **excavman** » Thu Mar 17, 2011 8:53 pm

I mounted the transducer a little differently. I used a plastic 10 oz coffee can (Folgers) and cut most of the bottom out leaving a lip about 3/8 in wide. I smeared a thin coating of silicon on the inside of the hull where I intended to mount it then after that dried I gobbed a whole bunch around the edge of the can bottom and set it in place. The next day I filled it half full of water and ran the wire throught the a hole I cut in the lid then dropped the unit in the water, put the lid on the can and ran the wire. It works great.

Larry