Transducer

bv0820 · Feb 14, 2005

I have an epoxy transducer...work fine. Also had one immersed in water in an inverted bowl..also fine.

Bob Vogel
Laughing Gull 1877

o.com wrote:

Blue Fin actually came with a hummingbird fishfinder that we use for
soundings. The install is temporary in a box filled with water.
I've heard that you can bed the transducer in epoxy right to the
hull and thus avoid adding holes to the boat.

#1. Has anyone done this--the epoxy approach

#2. Why are fishfinders so much cheaper than official transducers?

Thanks,

Victor

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imbissfrank · Feb 14, 2005

Bob,

Is yours also Hummingbird? I bought one a while back, and have not hooked it up yet. Too darn many thru-hulls as it is.

Frank Gallardo Jr
V-2184 Cin Cin
Fair Winds and Following Seas

Robert Vogel bv0820@... wrote:

I have an epoxy transducer...work fine. Also had one immersed in water in an inverted bowl..also fine.

Bob Vogel
Laughing Gull 1877

o.com wrote:

Blue Fin actually came with a hummingbird fishfinder that we use for
soundings. The install is temporary in a box filled with water.
I've heard that you can bed the transducer in epoxy right to the
hull and thus avoid adding holes to the boat.

#1. Has anyone done this--the epoxy approach

#2. Why are fishfinders so much cheaper than official transducers?

Thanks,

Victor

Blue Fin V 1553Yahoo! Groups SponsorADVERTISEMENT
document.write('');

emmajen5 · Feb 14, 2005

Victor,

I bought a fishfinder made by Navman to replace my old depthsounder.
It has a "Navigation" mode which has some nice features including a
very bold and large readout. I assume that stand alone depthsounders
are more accurate and perhaps read deeper? I've often wondered about
why they are more expensive too. Another feature about Navman that
was attractive was that they sold the transducer separately and
offered one that was designed specifically for "in hull" rather than
"through-hull" installation. They recommended epoxying it to the hull
but I ended up epoxying a short length of capped PVC pipe instead
which is filled with water. It's worked fine so I've left it that
way. The Navman transducer installation manual is on the Plastimo
site if you want to read what they have to say about it.

Home page | Plastimo, happy boating to you

Plastimo : fabricant et concepteur de Sécurité, Mouillage, Navigation, Pont et Accastillage.

www.plastimo.com

Garry
"Raven" V.2427

dewiniaid · Feb 14, 2005

As I understand it transducers these days are generally 200kHz and/or
50kHz the difference is the 50kHz will go deeper(lower freq travels
father) but has less resolution. In determining if your old Xducer will
work with the new guage you'll also want to check power rating a
instrument putting 300 watts to a 100 watt Xducer might blowout the Xducer
where as the other way around may not provide sufficient power to function
at all. I do not know what range of power difference would be tolerable to
the instrument/ducer I suppose it would be instrument specific. (power
output might be the cost difference between 'fish
finders'/'depthsounders'?)
BTW for inhull installation I've also heard of putting mineral oil in the
PVC pipe as opposed to water, I do not know what the difference would be.
I picked up a raytheon L365 fishfinder with bronze thru-hull
speed/temp/depth for around US$60 at Boat-US (discontinued sale, combined
with a few $10 gift certificates, and discount for getting the warranty)
at that price I wont be too upset if it breaks in a couple years.

--
James Ward
Fortunes Lady (v1469)

pelagicasd · Feb 15, 2005

We have both a fishfinder and a depth sounder. They both work pretty good
but if we run them at the same time they tend to confuse each other.
Fishfinders are made for power poats. Depth sounders can be made for either
power or sail. They both depend on soundwaves bouncing off of the bottom and
returning to the transducer. There is a difference in the way they do this.
The waves spread out in a cone shape as they leave the transducer. Sailboat
transducers have a wider cone. If the boat is heeled the cone is not pointed
directly at the bottom and the depth readout may appear to be deeper than it
actually is. The sailboat transducer having a wider cone will contact the
bottom closer to the boat (as well as futher away). Kind of like a
flashlight that can focus it beam. Held at an angle the distance from the
edge of the beam to the flashlight is greater on a narrow beam than on a
wide beam. Hope this makes sense.
As far as epoxying the transducer to the hull it can be done but not
without some degradation of the signal. The thicker the hull the more
degradation. The transducer should look straight down and that can be
difficult to achieve without using a thruhull. It should also be mounted so
that the keel doesn't interfere with the cone. Transducers can be put in for
temporary use by duct taping them to the hull. You have to avoid having air
between the hull and the transducer. As weird as it may sound you can do
this by smearing it with peanutbutter first.
Walt,
S/V Lyric #120

eagervega · Feb 15, 2005

Hi all
Reading with interest about fishfinders and depth sounders.

Two Vegas in our marina changed from echosounders to Fishfinders and
are very happy. The model is Garmin 100 and in my opinion is far
superior to any depth sounder I have used. Also the price is only
approx 130 Euro. With practise you soon get a very good idea of the
type of bottom, and also you have a history of the last minute or so.
An added advantage is the volt meter.

We installed the transducer inside the hull under the starboard
berth, just inside the aft locker sliding entrance. We used Silkaflex
although I am told any cheaper Silicone will work perfectly. Just
squeeze out a blob approx 2" square and then push the transducer into
it with a circular motion. Leave for an hour or two for any air
bubbles to dry out. Should work perfectly, however it is a very easy
job to redo if there is any problem such as air voids in the hull at
that location. Just move a few inches in any direction. Its worked
first time on two Vegas and at least 2 other yachts here.
Because this area is not flat the sounder only works to about 20
degree heel on starboard tack, but will work to any heel angle on
port tack. However the depth readings are very accurate. If you want
to mount the transducer level it can be simply done by cutting a
section(About 2") of plastic bottle of diameter approx 3" or 4"
(depending on the size of transducer)and placing it at the located
place. Again put a big blob of Silicone inside and push in the
transducer but this time keeping it level. Its important that the
face of the transducer is positioned so its facing through the hull
and not through the side of the plastic container.
Hope this makes sense, it is really very simple and I personally
would hate to use epoxy. It sounds a bit too permanent for my liking!

Best of luck and looking forward to chatting to you all again in the
future,

Nigel. "Eager Vega" V 3314

Kilmore Quay, Co. Wexford, Ireland.

PS. There are 2 other Vegas at Kilmore Quay ("Samedi" and "Wild Tyme")

emmajen5 · Feb 15, 2005

Nigel,

An interesting feature of the Navman transducer is that it is designed
with a bevelled end to compensate for the angle of the hull. I
mounted mine just aft of the water tank and port of the centre line
but the bevel allows it point directly downwards. The idea of using
epoxy directly on the unit scared me too. It sounds like silicone is
the answer.

Garry
"Raven", V.2427

rolyatad · Feb 16, 2005

I also installed a 3100 series Navman, as the old transducer was of
the wrong frequency. I epoxied the 'ducer at one of the flattest
places I could find, starboard side of C.L., aft end of the cockpit.
It has worked great there, no problems, for three years. I looked
for an internet sale and bought it as cheap as possible.

Doug, #712

jkepleriv · Feb 18, 2005

To add another alternative mounting scheme. In my Albin 79 I had a
Navico depthsounder. Glued a 2.5 in PVC pipe to the inside of the
hull with silicone glue, drilled a 5/8 in hole in a PVC cap. got a
second 5/8" nylon nut, bolted the threaded rod on the transducer to
the cap. Filled the pipe (abut 4 inches tall) with Castor oil
(Navico was British!) Then set the cap down on the section of pipe
glued to the hull, immersing the transducer in the oil.
The hull under the v-berth was ~ 1/2 inch thick. Had severely
limited depth range, but then the water does not get too deep here
on the Texas coast and measuring shallow water was a lot more
important to me.
Actually I cut three pieces of pipe. a guess at the angle then one
10 degrees on either side of my guess.
Gets the transducer parallel with the keel easy maintenance.
Mineral oil probably works as well as Castor Oil and does not
support biological activity.

Don Shelton
Former owner Albin 79
frequent crew on Vega