mineral spirits is OIL, use acetone to clean the ground polyester/glass

yeah, I agree. if an "in hull" transducer works, why put extra holes in
the hull? Also, what about 3M 4200? it is supposed to be bedding
rather than bonding, it's what I used to install my two through hulls.

does a fish finder use the same transducer as a simple depth sounder?
It would be handy to be able to use the same transducer, since changing
them out is a chore, and involves hauling out the boat.

Luc wrote:
does a fish finder use the same transducer as a simple depth sounder?
It would be handy to be able to use the same transducer, since changing
them out is a chore, and involves hauling out the boat.



The fish finders I see use a 'transom mounted' transducer.
I don't think this is a good spot on a sailboat like mine...with the
rudder hung on pintle & gudgeon, and the outboard mounted on it's bracket.
I'd want the in-hull type I could mount in my cabin just forward of the
keel box. (cut down on turbulence)

Mys Terry wrote:

I bought a cheap Humminbird and set that "transom mount" transducer in
a blob of clear silicone in the bottom of my boat just ahead of the
keel and it works just dandy, despite all the warnings about not doing
exactly that in the Humminbird instructions.

Just make sure the blob of silicone doesn't have any air bubbles.

The fish finder my wife bought for me came with a transom
mount transducer, _and_ instructions about how to mount it
inside the hull if you did not want to do the transom mount
thing.

IIRC the method was similar to what you did, although there
was a section about making a temporary mount that you could
slide around before you put the glue in place. That was to
make sure that you selected a good location without voids,
etc. for the transducer to shoot through.

Since I was mounting it on a power boat with only the ski
locker and engine compartment accessible for interior
mounting, I put it back on the transom, and ran the cable
through a hole high above the water line. If I were to add
a similar unit to my sailboat, I would most certainly mount
the transducer inside and shoot through the hull. The only
drawback is reduced range, and the transom mounted unit
already sees down to over 200'.

Don W.

I had a fishfinder that I located slightly offset (flatter surface) behind
the keel. I puttied a PVC tube just larger than the transducer onto the
surface, filled it with mineral oil, then put the ducer in there to test it.
When I was satisfied it worked, I glassed in the PVC, put the ducer back in,
then refilled the tube with oil. I also put a cap on the top of the tube to
keep the oil from sloshing out. Worked fine, even with the slight angle. It
wasn't accurate for over about 50 foot depth, but who cares at that point.
No extra holes in the boat is my preference.

--
"j" ganz @@
www.sailnow.com

"Don White" wrote in message
...
Luc wrote:
does a fish finder use the same transducer as a simple depth sounder?
It would be handy to be able to use the same transducer, since changing
them out is a chore, and involves hauling out the boat.



The fish finders I see use a 'transom mounted' transducer.
I don't think this is a good spot on a sailboat like mine...with the
rudder hung on pintle & gudgeon, and the outboard mounted on it's bracket.
I'd want the in-hull type I could mount in my cabin just forward of the
keel box. (cut down on turbulence)

Mys Terry wrote:
On Wed, 29 Mar 2006 22:25:27 GMT, Don W
wrote:



Mys Terry wrote:


I bought a cheap Humminbird and set that "transom mount" transducer in
a blob of clear silicone in the bottom of my boat just ahead of the
keel and it works just dandy, despite all the warnings about not doing
exactly that in the Humminbird instructions.

Just make sure the blob of silicone doesn't have any air bubbles.

The fish finder my wife bought for me came with a transom
mount transducer, _and_ instructions about how to mount it
inside the hull if you did not want to do the transom mount
thing.

IIRC the method was similar to what you did, although there
was a section about making a temporary mount that you could
slide around before you put the glue in place. That was to
make sure that you selected a good location without voids,
etc. for the transducer to shoot through.

Since I was mounting it on a power boat with only the ski
locker and engine compartment accessible for interior
mounting, I put it back on the transom, and ran the cable
through a hole high above the water line. If I were to add
a similar unit to my sailboat, I would most certainly mount
the transducer inside and shoot through the hull. The only
drawback is reduced range, and the transom mounted unit
already sees down to over 200'.

Don W.


My boat does not have any coring in the hull, so I just picked a convenient spot
and it was fine. If it hadn't worked, it would not be a big deal to move it. I
put the blob of silicone next to an upright and screwed the hinged bracket of
the transducer to that to help hold it securly. To check around easily for a
good spot, just fill and seal a ziplock sandwich bag with water. Rest the
transducer on top of that from a few locations until you find a good spot.



Thanks for the tip on the ziplock bag. I'll try that.

Dave,
I know what 3M says. That advise I just gave you is free. That lesson cost
me $10,000. Your call.
Steve

"Dave" wrote in message
...
On Tue, 28 Mar 2006 07:19:14 +0200, "Steve Lusardi"

said:

Please remember 5200 is an adhesive, not a sealer.

Take a look at 3M's marketing materials. Then go to the corner and put on
the little pointed hat.

"Jere Lull" wrote

5200 is too strong for that. You'll have to cut it out when you want
to
replace the knotlog. I'd suggest 4200, which is plenty strong. Prep
of
the fiberglass is key. Nothing will stick to an oily or otherwise
slick
surface

Quite right. It is only the block itself that I'm putting in with the
5200. The through hull will be set in something else which is similar
to 4200 but I've forgotten the name. I do want to be able to get that
out someday!

You can see it he

Http://home.maine.rr.com/rlma/Strider0604.htm#Block

You might find the clamping arrangement interesting. I'm going to
leave it in place until the last possible moment so the 5200 if fully
cured. I scraped to bare glass and washed with acetone. If anyone
ever wants to change this installation, good luck.

--

Roger Long