Several posts recently about setting transducers in a tube filled with
mineral oil. The problem noted was the mineral oil eating through the
adhesive that affixes the tube to the fiberglass. I found a reference
that stated Sikkens Sikaflex is the adhesive of choice for this
endeavor. I'm going to give this a whirl in the next week. Although I
don't see what keeps the transducer from bouncing around in the mineral
oil.

It doesn't bounce around in the mineral oil. The tube fits the transducer
properly. The purpose of this is to allow transducer removal for maintenance
without hauling out, but it isn't for free. Even the best installations
attenuate the the transducer and performance suffers. On commercial ships,
they use a ball valved cavity that works much better.
Steve

wrote in message
ups.com...
Several posts recently about setting transducers in a tube filled with
mineral oil. The problem noted was the mineral oil eating through the
adhesive that affixes the tube to the fiberglass. I found a reference
that stated Sikkens Sikaflex is the adhesive of choice for this
endeavor. I'm going to give this a whirl in the next week. Although I
don't see what keeps the transducer from bouncing around in the mineral
oil.

On Sun, 20 Aug 2006 07:51:21 +0200, "Steve Lusardi"
wrote:

It doesn't bounce around in the mineral oil. The tube fits the transducer
properly. The purpose of this is to allow transducer removal for maintenance
without hauling out, but it isn't for free. Even the best installations
attenuate the the transducer and performance suffers. On commercial ships,
they use a ball valved cavity that works much better.

Using that same technique, I installed a thru hull transducer system
earlier this year for use with my Furuno NavNet system. The sounder
module has a peak power of 600 watts and runs at 50 khz, 200 khz or
both. On the 50 khz setting we were getting reliable readings up to
about 1700 feet of water.

To say that I was surprised and impressed would be an understatement.

The transducer locks into a plastic housing which I bedded with 3M5200
and cured for 3 days before filling the housing with mineral oil. I'm
guessing at the thickness of fiberglass that the transducer is
shooting through but suspect that it is at least 3/4 inch, possibly
more.

Thanks for your replies. I have a Grady-White that has lots of foam in
the hull with one thin area in the stern (as noted by the
manufacturer). Placing a transducer there yields a clear bottom scan
with a thin line at the surface (the hull) that doesn't seem to mess up
the readings to a noticeable degree.

All I really want is some assistance in avoidance of running aground in
the tributaries of Chesapeake Bay where I fish. Looks like this method
will work for me and minimize the bubble risk with epoxy.

Thanks again.

Thanks for your replies. I have a Grady-White that has lots of foam in
the hull with one thin area in the stern (as noted by the
manufacturer). Placing a transducer there yields a clear bottom scan
with a thin line at the surface (the hull) that doesn't seem to mess up
the readings to a noticeable degree.

All I really want is some assistance in avoidance of running aground in
the tributaries of Chesapeake Bay where I fish. Looks like this method
will work for me and minimize the bubble risk with epoxy.

Thanks again.

I stuck the outboard boat style transducer to the inside of my sailboat hull
with a BIG gob of silicone RTV caulk, works good, but only to ~350'. I
stuck it in the wet caulk and it worked, otherwise I would have cleaned up
the wet caulk and tried something else. That transducer was included with
the Garmin 100 Blue fishfinder, which is a great unit with NMEA output that
I view on my chartplotter. A "puck type" transducer would cost almost as
much as the fishfinder!
Lee Haefele
wrote in message
ps.com...
Thanks for your replies. I have a Grady-White that has lots of foam in
the hull with one thin area in the stern (as noted by the
manufacturer). Placing a transducer there yields a clear bottom scan
with a thin line at the surface (the hull) that doesn't seem to mess up
the readings to a noticeable degree.

All I really want is some assistance in avoidance of running aground in
the tributaries of Chesapeake Bay where I fish. Looks like this method
will work for me and minimize the bubble risk with epoxy.

Thanks again.