Just so there's no mistake here -- the galvanizing, etc. was done by
the builders to the Royal Navy spec thirty years ago. We're just
working within the framework (or should I say "maze" or maybe "rat's
nest") that we inherited. See the web site for more details.

You mentioned stainless -- do you have any thoughts about it? My
general feeling is "worried" when I think about stainless and hot
running salt water, or even cold stagnant salt water. I suspect that
the galvanized mild steel will last longer and fail more slowly (it
begins to weep), but I'm not a metallurgist.....

And, yes, PVC, even Scd 80, has its problems. We'll use it only for
bilge and freshwater suctions, not seawater, and not in the engine
room.

Jim Woodward
www.mvfintry.com

DSK wrote in message ...
Jim Woodward wrote:


Take a look at http://www.mvfintry.com/pix/manifoldbilges800.jpg
Every piece of pipe you see was custom welded and then galvanized
after welding. It won't burn, won't burst, and won't have hose clamp
failure.

DUDE! Galvanized? I'm impressed. You obviously spent a lot of time & money working out a good
engineering plant, did anybody suggest seamless SS piping just for laughs?


It will eventually rust through, but yearly inspections deal
with this -- rusting is obvious and slow. (We will, however, replace
most of it outside of the engine room with schedule 80 PVC).

Probably a smart move, although I've seen vibration cause trouble with PVC longevity, outside the
engineroom it shouldn't be an issue.



Whenever you get the chance, go aboard government and industrial boats
and make notes -- you'll learn a lot about really designing for
reliability and maintainability.

Thanks, that's where I cut my chops starting an embarassingly long time ago.


A trip to the Work Boat show in New
Orleans (early December) can be eye-opening for someone whose only
boating is on yachts.

Thanks for the tip, I have some friends in N'awlins we love to visit.

Fresh Breezes- Doug King

"Jim Woodward" wrote in message om...
SNIP
You mentioned stainless -- do you have any thoughts about it? My
general feeling is "worried" when I think about stainless and hot
running salt water, or even cold stagnant salt water. I suspect that
the galvanized mild steel will last longer and fail more slowly (it
begins to weep), but I'm not a metallurgist.....

Do you ever visit www.metalboatsociety.com? They have a set of
discussion forums and, since the emphasis is on metal, tend to discuss
such issues. In case you've not visited, it isn't at all obvious (at least
to me) as to how to go to the discussion forums. The way I get there
is to click on the "Search" link on the homepage and then click on
the "Metal Boat Society Forum Index" to get to the forum index.

- Julian.

Jim Woodward wrote:

Just so there's no mistake here -- the galvanizing, etc. was done by
the builders to the Royal Navy spec thirty years ago. We're just
working within the framework (or should I say "maze" or maybe "rat's
nest") that we inherited.

It's kinda fun though. Isn't it amazing how you start out with a huge amount of space for absolutely
everything, and then you find that "everything" takes up more space than you thought? Having all valves
labelled is crucial.


See the web site for more details.

It's a great web site but many of the pictures have 'google' stamps instead of a picture.




You mentioned stainless -- do you have any thoughts about it?

Yep, it's way too friggin expensive and the electroformed pipe (rolled & welded instead of seamless) is
almost always fails along the joint. IMHO galvanised mild or hi-carbon steel is much better even if
neglected.



My
general feeling is "worried" when I think about stainless and hot
running salt water, or even cold stagnant salt water. I suspect that
the galvanized mild steel will last longer and fail more slowly (it
begins to weep), but I'm not a metallurgist.....

Also, you can spray on that "cold galvanise" rust inhibitor and do pretty well. Usually corrosion is
worst along joints & flanges. For places where you really want minimum corrosion and have money to
burn, monel is the way to go.

The boat looks really great, it's a huge project and the vessel has marvelous possibilities. We are
finding our 36 footer to be plenty enough work, though!

Fresh Breezes- Doug King