16' SS Transom Transducer location for high speed. Please help

[PlayD0h]

So I've tried to mount my Transducer 2 or 3 times on my 1982 16 SS at the spots I would assume it should go, based on instructions and the info available.
However I can't get high speed readings. I was wondering it would probably be best to just ask here and find out what positions others use and have success, rather then drilling more holes.
Which BTW I need to learn what the best way to seal the now "wrong holes". I've just put a screw in with some silicone injected in to the hole first, but that's Mickey Mouse.
I've got a semi-soft spot on the deck, near the rear so I might pull the trigger and do a restore, yet I'm think I might just do the rear half of the boat deck, since my ultimate plans on seats wont work with my now Toddlers.

 

[Alumarine]

I can't help you with the preferred mounting position but you could seal the holes with 3M 4200 or 5200.

I usually mount a piece of wood 3/4"x6"x8" in the approximate area that I think the transducer will work.
Then if I need to make multiple holes I'm not messing up the transom.

 

[dozerII]

It is real tough to find the perfect spot for high speed. You need to be between strakes on the bottom of the hull, and far enough away from the motor to stay out of the bubbles, plus the transducer has to be exactly the same height as the bottom of the hull. Even doing it just as the instructions say sometimes just rivets can cause enough turbulence to screw it up at high speed. Sorry if that wasn't much help but that is my experience, on my Holiday I followed the Humminbird directions to a Tee and it still won't read at high speed.

 

[alldodge]

I am currently replacing part of my transom because I did not seal the hole properly. What I will be doing this time for all holes below the water is, drill the hole large enough for the screws (1/8 inch). Then drill a 3/8 hole, an fill will marine-tex. Once cured, re-drill the 1/8 hole for screws. Fill holes with 3M 4000 and install screws.

This way if it starts to leak, which it shouldn't the water goes in the bilge and not into the transom wood core.

Agree, between the strakes, and the transducer is just under the water. Personally I like the shoot thru the hull type but most have temp senders which need to be in the water. On the other hand if you don't care about knowing what the water temp is exactly, mount it inside the hull and allow it to shot thru

 

[cj8mule]

What these guys said! Here's a picture cause a picture is worth a thousand words:




The white board is what marc c is talking about. This position worked OK for me but I did have to tweek the transducer a little to get a good reading at speed.

 

[laurentide]

Same deal here, but I used PVC board glued on with 5200. Then you can move it around to find the sweet spot.

 

[PlayD0h]

Great advice guys, just what I needed. I might just save the time and my Transom and look at getting a through hull. I had actually wondered if they'd work through aluminum, but forgot all about that route. Great idea about the plate/board.
Thanks a bunch.

Just checked Through hull Ducers. $300 (Canadian) with $20-$40 shipping. Ouch. Guess I'll be trying the plate idea, or just slowing down, lol

 

[Watermann]

Sorry the through the hull transducer pucks won't work on an AL boat and have to be bedded in epoxy with no bubbles to shoot through FG.

On the holes you've bored in the wrong spots, if the hole is below the transom wood then you can just coat a closed end blind rivet in 5200 and pop it in place, that's as close to a permanent fix as anything for the time being. NO NOT use silly cone. Be sure to only use SS screws with 5200 if the hole goes into the transom wood. I would use a poker to smear the 5200 around inside the hole too before driving the SS screw in and let the screw displace the excess.

The amount of movement needed to find the sweet spot can sometimes just be a tiny bit but normally I've found to get it right, it's the angle the front of the transducer has on it. The transducer I have comes with wedge shims and I had to play around with it a few times getting the depth and angle correct.

Good luck and if you would post a few pics of your SS for us to check out please.

 

[PlayD0h]

No Title

These are a couple years old, when I first bought it, but aside from the trolling motor and sonars, plus a few accessories its pretty much the same for now.