I was posting
this in another position. Anyway some of you will remember that I was trying to know wich were the specification for material used by Beneteau
from 2009 for seacocks. My question was of course following the problems occurred to some yachts and the plenty of talks about seacocks, and tests from Yachting M., that moved me to panic. A lot of interesting informations came from this forum and other from this blog, but I finally had the official answer: it lets me complitely astonished the way they declare with absolute quiteness the **** they use for these u der water
items, sorry for this, and sorry for my english
: I'm from Firenze, Italia.
Here is the text:
For more than a decade, Beneteau
has been installing brass thru hulls which composition is CuZn40Pb2 (CW617N).
The composition is defined as follow: Zn40= 38% zinc, Pb2= 2% of lead, and the rest as copper 58%
Others materials, aluminum
, tin, nickel, steel
, manganese, silicium, antimony as well as arsenic are used to a total of 2%.
These thru hulls have been made in Italy
for over 40 years for a usage in a sea water environment
However it is clear that, like any materials submerged in seawater, brass, over the years, will deteriorate due to chemical or electrical electrolysis
is happening from stray current
coming from the boat electrical system
or from shore (docks as well as others surrounding boats)
Electrolysis is also coming from other materials in the water that create an electrical current
that result in corrosion
(batteries, metal structures).
To our knowledge, corrosion
on thru hulls are episodic and in non-significant quantities in the one boat per thousand.
We recommend an annual inspection
of all thru hulls for a color change (from yellow to pink) as well as a regular replacement of the anode zincs and if necessary the addition of more anode.
The webmaster for the spare parts