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In-Hull, Adjustable Angle Transducer

Posted: Fri Jul 06, 2012 1:03 pm
by Windward
I'm up grading with a new Garmin 546s chartplotter and sounder, I'm going to install the in-hull type transducer
do any of you have any experience with this installation?? do any of you know if the freedom 1987 30' has any balsa core or is the hull solid fiberglass????
what do ya know?
Thanks Terry

Re: In-Hull, Adjustable Angle Transducer

Posted: Fri Jul 06, 2012 2:54 pm
by Tricia
Hi Terry,
I just replaced a transducer. The hull is balsa cored. The previous transducer had just been bedded in sealant and the balsa was dry as a bone, but I routed back the balsa and filled with epoxy, then redrilled. A bit of work, but the peace of mind is worth it.

Tricia
F30 "Muse II"

Re: In-Hull, Adjustable Angle Transducer

Posted: Fri Jul 06, 2012 3:59 pm
by rvivian
The hull is mostly balsa cored except for some areas around the hull to keel attachment from what I understand.

Somewhere on this site I read a message (by Al Lohman maybe ???) that said an in-hull transducer can be mounted just in front of the keel where the fiberglass is solid. I have not got to that part of my list of projects yet.

I read another post that said one can (carefully) remove the inner skin and balsa, leaving the outer skin intact and then mount an in-hull transducer there. I would probably carve out the balsa down to the outer skin, route some balsa out from between the skins, fill with solid fiberglass reinforced epoxy and then mount the in-hull transducer on the new solid area of the hull.

From her message - I think Tricia cut a hole for a new transducer, routed balsa around the edges filled the whole thing with epoxy and then drilled a hole through it and mounted a through hull transducer. That is the most common method.

Re: In-Hull, Adjustable Angle Transducer

Posted: Fri Jul 06, 2012 8:02 pm
by jdpandlp
I mounted a transducer that shoots thru the hull on my 39 Express. To find a place that would work I used glazing compound to fix a short piece of 4 in drain pipe to the inner hull. I then filled the pipe with mineral oil and just dropped the transducer in. If you get a signal you have found your spot if not just pop it loose and try another place. The transducer I used is the same item used as a thru hull mount. When you find your place contour the pipe to get a close fit an epoxy it inplace. I used 4 inch plastic pipe with a screw in end plug that i drilled out and pounted the transducer in. Once you have mounted the transducer in the plug just screw it into the pipe which you have filled with mineral oil. A second small vent hole needs to be drilled so all the air would be forced out as the transducer was screwd in. When oil start being forced out, plug the vent.

I did this because I did not want to haul mid season to replace the transducer. Though I have since replace the thru hull transducer I still use the internal one after 7 years.

Re: In-Hull, Adjustable Angle Transducer

Posted: Sat Jul 07, 2012 2:01 am
by Tricia
Just to clarify, I removed the old Datamarine transducer, and routed then filled the old hole and redrilled in the same place for the new transducer. Taking out the old one was a bit of a job, requiring a multi-master type tool, forstner drill bits, chisels, sweat, bruises and cursing. That being said, it was kind of fun doing the demo...

Re: In-Hull, Adjustable Angle Transducer

Posted: Sat Jul 07, 2012 2:00 pm
by mike cunningham
I have Freedom 30 #3 and just upgraded fro the original Datamarine instruments to Raymarine. The tramsducers, which were replaced same location slightly different bore, are installed several inches offset from centerline about two maybe 3 feet forward of the keel. There is no balsa at the ceneterline and for several inches either side.

In terms if core. Yes, the hull and deck are balsa cored with a few exceptions I am aware of, may be more. The entire transom is solid glass. The aforementioned centerline area, at least forward of the keel is solid. The deck also becomes solid about three inches inboard of the hull/deck flange.