[Mark]

I dont know how many of you fish. But im looking to put a fish finder on the boat and wanted to know if anybody ever epoxied the transducer to the inside of the hull ? If so how did it work. They say in the book you can do this but I do not know anyone that has hooked up a finder this way. I dont like to drill holes into the transom for the brackets. Thats why I would like to find out.

[mikeyt]

I was tempted to try installing the transducer in the hull in my old Stingray but i was way too afraid of cutting too deep and going right thru! I ended up mounting mine on the transom & running the cables thru the drain holes at the back. It wasn't pretty but it would have been easier to fix a drill hole in the transom than to attempt to patch fibreglass in the hull for me...

[bill.deweese]

Mark,

My experience with this is with a depth sounder, however I think that a fish finder is very similar on the transducer side and just the head-end is smarter. The big thing to be careful with is that the transducer signal cannot pass through air. This is why a depth sounder will flash "--" or "0.0" when your boat is running on the trailer. The signal can pass through fiberglass and the epoxy relatively unaffected so the "shoot thru hull" mounts can be a good option and you will not have to drill or externally mount it.

The other thing to avoid is any cored areas in your hull. My Shabah only has a small cored "square" in the bilge area to mount the float switch for the bilge pump. Since the head-end will likely work with a few different styles of transducer, the manual for the mount will be with the transducer kit. Once you pick a location you need to measure the deadrise angle and rotate your mounting position accordingly so the direction of the signal will be straight down. After all that, you can just use some sand paper to ensure that the mount area is clean and smooth.

The kit should come with or recommend the epoxy material. If you "shoot through" the epoxy then you need to make sure that does not have a lot of those pesky air bubbles. The transducer for the sounder that I installed was kinda cool. It had a cylindrical ring that was mounted to the hull (I used 3M 5200) and then once that was in place it created a cylinder. You fill the cylinder up with mineral oil and then you set the transducer down into the cylinder. You can then rotate the transducer in the mount to compensate for the deadrise angle. Once done, the transducer is set in place with two small screws that go into the top of the cylinder. So you only have a small bead of 5200 coming in to contact with hull and the "connection" to the hull is through the mineral oil so it is accurate (no bubbles in the epoxy).

Once you settle in on a brand, I would check that company's web site and see if you can download a PDF of the install instructions for their transducers. You can see which one you would tolerate. One last point. If you go with the shoot thru hull model you may loose some features like water temp and speed.

Thanks,

Bill DeWeese

[mikeyt]

So you dont have to cut into the hull at all if you mount it inside the hull?? damm....oh well. I did use the speed / temp measurements on my Eagle Matrix 15 so i guess i would have lost those features.

[WetWilly]

Hi guys,

Interesting thread here for sure! Our old transom mount was missing when we bought it, so I'm having to replace ours as well and I was looking at putting it in the hull too, but my concern is, will the transducer have to shoot any through foam filling?

From the brochures, Mariah stated that all voids were filled with foam. So basically our hulls are from the outside, gelcoat, fiberglass, foam fill, sub framing, foam fill and finally fiberglass again. So wouldn’t I have to grind down to the outer layer of fiberglass to get a good signal? If that’s correct, it would mean it would be pretty thin where the transducer would go and that makes me a little nervous! Further more, since it would have to go under the engine as far back as possible so it would register while at WOT considering only the back 1/3rd of the hull would be in the water, getting back there on our Talari isn’t going to happen unless we pull the engine. Guess I'll put the new one where Mariah mounted the old one, back on the transom.



Here is the hull lay-up for 1999 out of the brochure:




As you see from the picture, there appears to be a void under the rear bilge area and it doesn't state if this is solid or hollow so that could cause a problem for Mark if he goes with the in-hull installation.

Mark, hopefully a member with an in-hull setup on their Mariah will chime in soon, or maybe refer you to a shop that has done this to Mariahs before and get the details from them.

Good luck,
WetWilly

[ShabahZ280]

You guys are in luck! My transducer is an in-hull, the factory one Mariah used. However, the epoxy has gone bad, and I have to replace it. WetWilly's photo showing the "void" in the bilge is exactly where my transducer is/was located.

I've attached a photo, could quite possibly be the absolute worst photo on the site, but it shows the cutout, and the bad epoxy. It appears to be some sort of fiberglass casing/mount underneath, but it's not solid, it sounds hollow. It'll be a true challenge to try and replace it, because it's in the absolute most non-accessible section of the boat. But I'm thinking in early spring I'll try and tackle it. I've already got the replacement transducer just sitting in a box!

I'm not sure if Mariah ever put depth transducers on the transom. Maybe on the older models? The only transom mounted thing I've ever seen was the paddlewheel, which is used to measure distance traveled for the "trip odometer". Mine worked once...

[WetWilly]

Now you've got me wondering if the "transom" mount was really for the trip odometer only and not for the transducer. When I last checked, I did'nt see a transducerin the bilge. Maybe it was a combo unit, transducer and paddle wheel like mikeyt's unit??

Guess I'm going to have to trace the wiring from the Depth Sounder and Odometer back to the transom to see what I really have, oh joy, joy.....

I think I'll PM Moondance100 because he has the closest model to ours so hopefully he has the same setup with an odometer and sounder.

I'll let you know when I know.

WetWilly

[mikeyt]

Originally Posted by ShabahZ250

You guys are in luck! My transducer is an in-hull, the factory one Mariah used. However, the epoxy has gone bad, and I have to replace it. WetWilly's photo showing the "void" in the bilge is exactly where my transducer is/was located.

I've attached a photo, could quite possibly be the absolute worst photo on the site, but it shows the cutout, and the bad epoxy. It appears to be some sort of fiberglass casing/mount underneath, but it's not solid, it sounds hollow. It'll be a true challenge to try and replace it, because it's in the absolute most non-accessible section of the boat. But I'm thinking in early spring I'll try and tackle it. I've already got the replacement transducer just sitting in a box!

I'm not sure if Mariah ever put depth transducers on the transom. Maybe on the older models? The only transom mounted thing I've ever seen was the paddlewheel, which is used to measure distance traveled for the "trip odometer". Mine worked once...

That looks like an ugly replacement job....

[ShabahZ280]

Originally Posted by mikeyt

That looks like an ugly replacement job....

You should have seen the position I was in just to snap the pics! My girlfriend walked outside and said "It looks like your boat ate half of you!" All she could see was the bottom half of my body flailing around with the engine hatch open...

I'm most likely going to remove the engine cover, it looks like it slides out. That would make it quite a bit easier.

And there will be a full write-up for the site.


WetWilly, check the wiring schematics in the contributors section. The last page has the depthfinder schematic on there and could possibly help you out a bit.

[indykoch]

Mine is mounted inside as well, though not quite as difficult to reach as Chris'. Then again... I don't have a big block monster in the way!!!

My depth gauge flashes insanely high numbers more than the times it's accurate. I was planning to replace it with an external one hoping for more accuracy and for a water temp add-on.

I removed the odometer paddle wheel since it was in the way of my Smart Tabs and didn't work anyway... was thinking I'd use the hole in the hull from those wires for the transducer wires.

Did I answer anyone's questions or did I just type this to complain?!?!?!