I have been carrying on a parallel thread in r.c.metalworking. We found
a couple of sources for bronze and red brass pipe including the one Jim
found but not threaded nipple. Also they don't deal with small
quantities. You might find red brass nipples is an old fashioned
hardware store but 99% of the time it is yellow brass.

There is no real way without chemical analysis to determine the exact
alloy but the terms "brass" and "bronze" have no real engineering basis.
With the exception of silicon and some aluminum bronzes, all bronzes
have some zinc in them. To add to the confusion, some bronzes have more
zinc in them that some brasses do.

The only thing I can figure out is that the "true" brasses have copper
and zinc but no tin. If a bronze alloy contains any zinc it also
contains some tin. The tin evidently prevents dezincification. For
example "Naval or Admarilty Brass" is 60% copper, 39% zinc and 1% tin
but it is not subject to dezincification and is actually classified as a
bronze.

Red brass is also actually a bronze rather than a brass. The bronze that
Conbraco and other marine fitting companies use is actually red brass
C83600. 85% copper, 5% lead, 5% tin and 5% zinc. (That from a poster
who works in the casting department of a marine fittings company.)

Yellow brass is a true brass at 63% copper and 37% zinc and highly
suseptable to dezincification. Common brass nipples are yellow brass.
Fortunately it is fairly easy to spot yellow and cartrige brass. Scrape
it with a file. Fresh yellow brass will have the characteristic bright
yellow gold color. Red brass will be more orange.


Keith wrote:
A hardware store near me carries what they claim are bronze pipe nipples.
They are dark, not like yellow brass, except where they are threaded. I used
one to mount an aqualarm next to a strainer. I wish I could figure out how
to verify that, short of a chemical analysis! If they really are bronze,
they might be the only people in the USA that have them!

"Glenn Ashmore" wrote in message
news:6tRpb.999$62.845@lakeread04...

I am building a manifold to feed the washdown pump, air conditioning
cooling pump and watermaker bost pump. The supply is a 1 1/2" hose
coming from a 1 1/2" bronze seacock and Groco 970-1515 strainer. Engine
cooling water is supplied through a 1" hose that comes off a 2"x1.5"x1"
Groco manifold at the strainer

I would use bronze reducing tees except that nobody makes bronze pipe
nipple. Only steel, brass or stainless. All three of which are not
acceptable. So I have decided to fabricate it from a length of 1" wall
PVC tube with 1/2" threaded schedule 80 stubs for the valves.

Now comes the question of the valves themselves. I have some Conbraco
bronze ball valves that would work but my experience with them in the
past has not been all good. While the valve body is bronze the handle
is mild steel. On several deliveries of older boats the handles have
rusted to the point of being unusable and I have had to resort to Vice
Grips to operate the valve.

OTOH, I also have some Schedule 80 all PVC ball valves with stainless
handle retaining screws. I know that ABYC frowns on using PVC on
throughhulls but if the throughhull has a bronze seacock what are the
rules for down stream valves?

--
Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com





--
Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com