depth transducer removal question

[karonoko]

I have searched this topic on the Board and did not find what I was looking for...
I am replacing my (original 1981!) DM depth guage and transducer - bought a Moor.

My question is this - the old transducer is in a nice bronze thru-hull (and i noticed my PO never protected it with a clevis pin...), and the transducer won't budge. Stuck in their like the old Luther Little in the mud in Wiscasett...but they removed her.

I am reluctant to break the great seal on a beautiful bronze tansducer, only to replace it (or worse - do so with the plastic thru-hull that came with the Moor) - I would prefer to remove the transducer, only. Is this possible? If so does anyone have a recommendation for how?
One thought was to drill through it, hook on and pull it out. Looking for someone who has faced this.

Many thanks. Tom (Scotia CD 27 #216)

[Phil Shedd]

Tom

A couple years ago I replaced the DM transducer like you discribe. I cut the cable ,removed the nuts and then was able to get the shaft to move a little bit by using a pipe wrench but just a bit. This told me the bond between the boat hull and the transducer was broken some. Not having any luck moving it futher I went to the brute force method. I placed a block of hard wood on the end of the trasducer and hit it with a very heavy hammer. I had hit it very hard but the transducer did move and came out with out damage to the boat.

The old transducer had been bedded in 4300 . The 4300 had been places on the threads and base so the whole unit was covered except the area that was showing. I cleaned the hole and removed any old 4300. Then installing the new unit ( direct replacement) i installed the same way with 4300.

After installing I ran the new wire to the gauge and removed the old wire. I found a coupling on the old wire that was hidden from view that was completely rusted and came apart in my hands . Oh Well

good luck

Phil

[bottomscraper]

I removed ours by drilling a 3/8" hole down the center of the bronze shaft using a long drill bit. I them made a puller
using a piece of threaded rod, several heavy fender washers, a flat steel bar with a 3/8" hole and a block of wood with
a large hole (large enough for the mushroom head to fit through, about 2" I think). The threaded rod went down the
center of the transducer with heavy fender washers and a nut on the inside of the hull. On the outside the wood block was
against the hull, followed by the steel bar and another nut. I just tightened the nuts and it pulled the mushroom head
out of it's home. I also sprayed with some sealant release product made by Boatlife, I'm not sure they still make it
but Debond is available and may be better anyway. Once the mushroom head was clear of the hull I used vise grips
to unscrew it the rest of the way. It was easy and required no big hammer.

I wish I had pictures, it would have saved me a bunch of typing

[Ron M.]

I replaced my DM depth gauge/trans. with a Moore a few years ago. They allowed an option for transducers, either a plastic one that came with the instrument or for a few $ more a bronze long stem thru hull. The bronze was almost the same dia. as the one I was replacing - 3/4". The plastic thru hull was larger - 2+ ".
I cut the cable, removed the nut, and slipped a length of pvc pipe over the old trans and levered the stem back and forth - breaking the seal somewhat. A couple of whacks with a 3lb. hammer and it let go.
The fairing block was removed also and re-bed. I've had good luck with their instruments on a number of boats.

[Carl Thunberg]

Thanks for the reminder. I remember that schooner wreck fondly. As a kid, I remember always looking for it out the window as we drove by. It was one of those landmarks that became iconic of Wiscasset. Still, time ravaged the old girl, and it came to remove her when she became an eye sore. It was sad to see her go.

[karonoko]

Thanks. It sounds like all of you removed the thru-hull - I was hoping not to. Any thoughts on that?

[Steve Laume]

I not only removed mine but got rid of the hole as well.

I glassed over the hull penetration with epoxy and built up a flat on the inside of the hull to mount the transducer. One less hole in the boat, no fouling problems or special paints, easy to get at and replace, no added drag from a large fairing block.

There is another thread that goes into more detail but these are my own thoughts on what to do with the transducer, Steve.

[bottomscraper]

Thanks. It sounds like all of you removed the thru-hull - I was hoping not to. Any thoughts on that?

Now that I look back at your question I realize we had different style transducers. The one I removed was an integral long stem bronze transducer, no separate thru-hull.

The following pictures are courtesy of DMI Marine:

This is what I had:



I believe this is what you have (only in bronze):



Depending on who made you existing transducer you may be able to just replace the core.

I would give Gemeco a call and see if they have something that will work:

http://www.gemeco.com/index.htm

They are the distributer for both Airmar and Radarsonics transducers.