Other than cost, is there any reason why you chose the plastic over the
bronze? In your case, I understand that you have a wood hull and are concerned
about stress cracking but I have never seen a good explanation on why you would
use a bronze transducer over plastic on a fiberglass hull, yet bronze seems to
be more popular.

Gary Warner wrote:

I just received my new depth finder and transducer in the mail. After
asking on newsgroups, reading Chapman's, and some West advisories I decided
on the Nylon Flush Mount thru-hull transducer.

The instructions that came with it say NOT to put it through a wood hull as
the swelling of the wood could stress/crack the transducer.

This boat is a lap-strake PLYWOOD boat. I know that planked boats swell a
lot to close/seal the gaps and calking. Do plywood boats swell much?? I'm
thinking they don't?

Is it OK to use this nylon transducer or should I send it back and pony up
the bucks for the bronze one?

Thanks,
Gary

"Jim Kelly" wrote in message
...
Other than cost, is there any reason why you chose the plastic over the
bronze? In your case, I understand that you have a wood hull and are
concerned
about stress cracking but I have never seen a good explanation on why you
would
use a bronze transducer over plastic on a fiberglass hull, yet bronze
seems to
be more popular.

Gary Warner wrote:


FROM THE INSTALLATION INSTRUCTIONS:

- Plastic housing recommended for fiberglass or metal hulls only.
NEVER install a plastic thru-hull sensor in a wood hull, since
swelling of the wood may overstress the plastic causing a fracture.

- Bronze housing recommended for fiberglass or wood hulls only.
NEVER install a bronze housing in a metal hull, because
electrolytic corrosion will occur.

- Stainless steel housing recommended for metal hulls to
prevent electrolytic corrosion.

- NEVER install a metal housing in a vessel with a positive
ground system.


MY THOUGHTS:

I'm pretty much a boating novice in many ways. When choosing between the
bronze
and nylon I tried to ask lots of questions here, to other knowledgable
boating people,
and do research on the net. I didn't find ANY reasons to use Bronze in my
situation.

My understanding after the research was that bronze would be better in
situations
where the transducer would have to be mounted on a steep angel portion of
the
hull and hence have much fairing-block around it. The bronze would be
stronger
in that situation. I got the general feeling that, of course, bronze is
just "better" and
that if money was no object...go bronze. (Unless you have steel/metal hull
or a
positive ground electrical system, then issues of electronic corrosion must
be considered).

In my case, it seemed nylon would be equally as good. I have a tendency to
want
to by "The Best" just for it's own sake. But the bronze was going to be
around $115
where the Nylon was around $55. I could find no reason to pay twice the
price.

But, as I said, the instructions with the nylon say not to use in wood. Had
I read that
first, I probably would have pluncked down the $60 more for the bronze. And
I still
would do that if I felt it was a safety issue. But I do not believe the
ply-wood is going
to swell.

I think I will make the hole just slightly bigger than need be so that any
small swelling
of the wood will not put pressuse on the transducer. I will - whether via
glass or
other method - make sure the transducer is in there VERY solidly. I do
know that
I don't want it coming out and leaving me with water pouring in.

Gary

Gary,
I'd be very cautious about epoxy/fiberglassing the stem/transducer in place.
If, for whatever reason it EVER 'goes South' you WILL have a BIG job {and
possibly HOLE} on your hands getting it out. Better to 'bed' it properly and
inspect it frequently.

On another point - WHENEVER you have a penetration of the hull - get a wood
PLUG that can be driven into the hole and/or fixture. {they come in sets, or
make your own out of Pine or Cedar - a relatively soft wood that WILL SWELL
when wet}. Wire or tie the proper size to the thru-hull and have a
short-handled, stout hammer aboard. If this is the only thru-hull, have it
tied there, as well.

If this sounds strange, check almost ANY book on off-shore sailing & SAFETY
ISSUES.

Regards,
Ron Magen
Backyard Boatshop

"Gary Warner" wrote in message
...

SNIP
I will - whether via glass or other method - make sure the transducer is
in there VERY solidly. I do know that I don't want it coming out and
leaving me with water pouring in.

Gary