Need advice about placement of transducer in hull

[boatin-on-cherokee]

I have purchased a Hummingbird 525, and once out on the water - it works fine for a few minutes and then the depth goes and if I am in 100 foot of water - it tells me 1.2 feet. And then I have to turn off and turn back on, and hope it reads correctly. This unit is brand new out of the box. Before I drive an hour and return it to Bass Pro, I was hoping to resolve this with a simple solution. The only issue that I can think of that would cause 'depth reading' problems would be the placement of the transducer. Right now, it is placed at the bottom of the hull, right next to the bilge pump. The issue that I realized is this " when I placed the transducer there with silicone as its base, I placed probably about 1/4 to 3/8 thickness of silicone underneath the transducer itself". Could this be my issue? Does it require just a small, thin layer to adhere to the hull?

Any advice would be greatly appreciated. I have used this forum before I have always got reliable info.

 

[flycaster]

Re: Need advice about placement of transducer in hull

I had the same problem when I bought a MARIAH 18' I had the place where I purchased the boat to install the transducer. I had told them that I didn't want it on the outside of the hull. They mounted it in the bilge area with epoxy. When I "complained" about the readings they responded that there needs to be a SOLID wall of material between the transducer and the water. If there is any air pockets in the hull material you will have problems. I had to have them drill holes thru the back of the hull and mount the transducer on the back below the water line.
Good Luck

 

[boatin-on-cherokee]

Re: Need advice about placement of transducer in hull

I appreciate your response. But after sitting here and doin some research, I realized something else. I used "silicone" and not a 2-part epoxy. Also, I remember turning the unit on the sale evening that I placed the transducer in the hull, thus possibly causing air bubbles.

Could I be on the right track?

 

[Tyme2fish]

Re: Need advice about placement of transducer in hull

b.o.c. Click on the Search function and type in "Transducer Mounting". Tons of replies.

 

[Paul DuLaney]

Re: Need advice about placement of transducer in hull

I've put transducers in the bilge of my last six boats and have had no problems other than on very choppy water and high speed they gave me a false reading.If I remember correctly in the instructions it stated not to use a silicone as some can be harmful to transducer.I've used a two part slow drying epoxy,put down about 1/4 inch and worked the unit in to get out any air.I try and keep them as close to the middle as possible as that is the flat area under the hall and gives the best and most accurate readings.Hope this can help you and good luck.

 

[NelsonQ]

Re: Need advice about placement of transducer in hull

Silicone is not to be used.

You need a 2 part slow cure epoxy to prevent bubbles epoxy and give proper readings.

If your device came with the transom mount, in the instructions is details on getting an flush mount inside hull transducer designed for that application. (They send you a new one free, you send them the one in the package in exchange)

Also ensure it's a single hull install.

They still indicate problems with readings in 'high speed' applications but never define what is high speed. (40+? or 60+? 80+?)

Here is the proper installation instructions from Humminbird for inside hull applications.

http://www.humminbird.com/pdf/transducer_faq/InsideHull.pdf

 

[Chris1956]

Re: Need advice about placement of transducer in hull

Not all places on the hull are suitable for mounting a transducer. The hull must be solid fiberglass with no voids, cores and not too thick. You can test-mount a transducer with just water. Place the transducer flat against the hull and have someone hold it in place or hold it down somehow. Get it wet and see how/if it operates. if it operates correctly, you can epoxy it down.

on my last boat (an I/O), I simply screwed the transducer (Hummingbird Wide)into the bulkhead and placed its face flat on the hull. There was enough water in the bilge to keep it wet. I never epoxied it in place, and it worked at all speeds for years. I sold it with the boat.

On my new boat, I could not find a spot in the bilge where the transducer (Garmin)worked. it is on the transom....