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On Thu, 3 Sep 2009 17:01:27 -0400, "mmc" wrote:


wrote in message
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On Thu, 3 Sep 2009 07:07:08 -0700 (PDT), Frogwatch
wrote:

On Sep 3, 6:28 am, wrote:
On Wed, 2 Sep 2009 20:04:03 -0700 (PDT), Frogwatch



wrote:
About three years ago, I moved my sailboat to a slip in a real marina
for the first time ever. I was surprised to see my shaft zinc go away
really fast. Then I noticed the edges of the bronze prop were really
rough and brittle. Uh-oh, So, I needed to get her bottom painted
anyway so had her hauled, not an easy thing to do around here (no
facilities). The bronze prop was a goner so I replaced it with a
PerfectPitch plastic prop that I like. However, the bronze shaft
strut also looked corroded but was good enough to last awhile. Now, I
have a diver check the zinc every 6 weeks.
So, I plan to haul her again soon and am thinking of replacing the
shaft strut.
Today, I dug out the old bronze prop whose blade edges were so
depleted of zinc that I could break off chunks of metal and examined
it. It was only near the blade edges that it was wasted of zinc
except a thin veneer of corrosion all over. The rest of it showed
good bronze when I used the dremel tool on it.
3 yrs ago when she was hauled, a small piece actually broke off near
the cutless bearing holder lip (not structural) causing me to think
it
was wasted badly. This experiment makes me not so sure that it is
bad. I can only determine this by using the dremel all over the strut
when she is hauled. Anybody have any experience with this?
Now, I can have a strut made but that will prob take forever, they
have to use the old one as a model and cast it. I will not be sailing
again till next year, no good.

Hmmmm.......I've got a well equipped machine shop, so, maybe I can
make a strut. Maybe I can make a strut base from silicon bronze, make
a strut body from another piece bolted and brazed to base with a
cutless bearing holder brazed to that. Thoughts?

Don't bother trying to fix your boat until the electrical problem at
the dock is fixed.

I will be moving but the boat manufacturer no longer exists (S2) and
its subsequent ancestor no longer has parts for 29 yr old boats. So,
what do y'all think about my making a shaft strut?

You could probably make one in a machine shop. On the other hand, a
lot of boats were broken up for parts after hurricanes in the gulf
coast area. You might be able to find a used strut pretty cheaply and
save yourself some time and effort.

There are boat salvage/parts operations with websites.


Or, you could send the old one to a foundry and have them cast a new one.
http://www.franklinnonferrous.com/se...FQO2sgodQlDlMA
or a marine machine shop http://www.hhprop.com/machining.html


Absolutely! If you can't find a used one, there are some more
complicated and expensive alternatives.

Right about that, I can't imagine having anything cast and machined would be
cheap.