Two Transducer Questions

The first question is about sealant. Is there any place I can get marine-grade silicone sealant besides at a boat place? Does anyone like Lowes, Home Depot, or Wal-mart carry it?

Second question is about the mounting holes for the transducer. If I replace an Eagle transducer with a Hummingbird transducer, will the holes that were drilled for the Eagle line up with the Hummingbird, or will I have to drill new holes? If it's going mean new holes, I may just leave the old transducer in place & put the new one near it.

Any tips, tricks, or hints I need to know?

BTW, the boat is aluminum.

Tugaloo

Wally World (WalMart) usually has marine sealant here in Pa. - So I'm sure they have it in all stores.

When I purchased my latest boat (used) it was missing the electronics but had the transducers still attached to the transom. I added all Garmin electronics, and of course the bolt patterns were different. I took stainless screws (just slightly larger then the holes), put sealant all over the threads and ran the screws into the old holes. That was 5 years ago - no leaks yet.

Did the same thing when mounting the new transducers. Cover the threads in sealant and run 'em in. This will build up under the bolt/screw heads like a washer would. I knew it was a complete seal by the amount of sealant that was on the inside of the boat as well. (not nearly as much, but it should still track in)

I want to say I used a 3M product of marine sealant - white. Can't recall the exact name on the tube anymore. (squeeze tube)

Zig...that 3M stuff is good. It will even seal
a leak under pressure while in the water.
I think leaving the old transducers..or fitting
new screws with the 3M sealant would both
be fine...and putting it on the new screws is
a good idea, too.

I've run into this situation (old holes in transom) and solved it by making a plate - one time with 1/8" thick aluminum and one time with a piece of plastic from an old cutting board to cover the holes and then sandwiched sealant between the plate and the transom and ran the screws for the new transducer through the plate and into the transom (after drilling pilot holes).

Those plastic cutting boards are great for “Jerry-Rigging” :) stuff. The plastic material can be cut with a circular saw or jig saw, drilled and sanded. I made a holder for my GPS unit out of part of that same cutting board.

You need 3M 5200 type silicone
SD

Quote:

---

Originally Posted by Jerry Blake

I've run into this situation (old holes in transom) and solved it by making a plate - one time with 1/8" thick aluminum and one time with a piece of plastic from an old cutting board to cover the holes and then sandwiched sealant between the plate and the transom and ran the screws for the new transducer through the plate and into the transom (after drilling pilot holes).

Those plastic cutting boards are great for “Jerry-Rigging” :) stuff. The plastic material can be cut with a circular saw or jig saw, drilled and sanded. I made a holder for my GPS unit out of part of that same cutting board.

---

I did the same thing Jerry, except I took the second board and made a hatch way cover out of it. Problem was I used two out of three of the wife's Pampered Chef boards. Yoweeee! She took it pretty well though, she only put a death wish on my minnows.

Bass Pro sells a transducer mounting plate. It's made from a material called StarBoard. Mount it one time and then you can move the transducer all around and not have to drill anymore hole in the boat.

If you run out of places to mount the transducer, just replace the plate with a new one useing the same mounting holes and start again.

I think it sells for about $9.95 and it cut real easy. The size is 4" X 12"

Gerald

Hey Guys. Some great help here. Thanks to all who posted. It may be a few weeks before I get to work on this. I score the baseball games for our HS team & that's keeping me tied up. Play-offs begin next week, but as soon as playoffs are over, I hope to get a chance to get back to the lake & my boat.

I bought the boat used & the transducer was already attached. The previous owner had bored holes thru the transom, and mounted the transducer with bolts & nuts. Heads outside the boat & nuts inside the boat. But the idea of attaching a piece of that plastic & then screwing the transducer to that is a great idea. I will, of course, cover the bolts inside and out with the sealant. But I do believe that this is going to work.

Also, I am now reading Huffman's "Season Structure" book & his Vertical Trolling book arrived in today's mail. Hopeful this is going to give me some good stuff to work with & the new Hummingbird 565 should work real nice.

Thanks to all

Tugaloo