"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