Blue color on bronze seacock

[hd002e]

I noticed a pretty strong hue on my head discharge seacock that is mounted on the floor at the head. I am color blind but pretty sure it is a blue color. Did I get the dreaded bronze disease or is this something else? How do I keep things under check? What do I do?

[pcmm]

That is really the normal bronze "green" tarnish that they get over time. Real worry happens when the bronze takes on a "pink" colour.

[hd002e]

I really appreciate this. As a colorblind solo sailor I was having a hard time. Thank you ��

[boatpoker]

That is "verdigris" often referred to as "patina". It is technically a form of corrosion but is so mild it poses no threat to the metal, in fact it actually forms a protective coating to a degree.

If it bothers you, you can remove it with a brush and some baking soda and lemon juice.

PS. The "pink" colour referred to happens to brass, not bronze and is due to dezincification caused by galvanic corrosion.
Brass has a much higher zinc content than bronze.

[JPA Cate]

Since the OP is color blind, he may want to take pictures of questionable colors he perceives, and show them to the guy or gal in the next berth, for finding out if the color means something. It might be quicker than waiting on CF.

Good luck with it. Verdigris is a strong color, sometimes quite deeply blue green, which must be a hard color for you. When a prop has the zinc deficiency disease, it usually appears with pitting, and obvious spread, in the same color as copper that is rubbed with lemon juice.

Ann

[boatpoker]

Originally Posted by JPA Cate

Since the OP is color blind, he may want to take pictures of questionable colors he perceives, and show them to the guy or gal in the next berth, for finding out if the color means something. It might be quicker than waiting on CF.

Good luck with it. Verdigris is a strong color, sometimes quite deeply blue green, which must be a hard color for you. When a prop has the zinc deficiency disease, it usually appears with pitting, and obvious spread, in the same color as copper that is rubbed with lemon juice.

Ann

Propellers that most people think are "bronze" are actually "manganese bronze". Curiously "manganese bronze" is actually a class of brass. When brass suffers from dezincification it shows a pinkish hue even before the pitting occurs.

[s/v Jedi]

Originally Posted by boatpoker

Propellers that most people think are "bronze" are actually "manganese bronze". Curiously "manganese bronze" is actually a class of brass. When brass suffers from dezincification it shows a pinkish hue even before the pitting occurs.

I think all marine bronze are in the brass family of alloys.

[boatpoker]

Originally Posted by s/v Jedi

I think all marine bronze are in the brass family of alloys.

Not quite. Lots of silicon, nibral and some phosphor bronze parts. All of the propellers my dad designed were silicon bronze.

[s/v Jedi]

Originally Posted by boatpoker

Not quite. Lots of silicon, nibral and some phosphor bronze parts. All of the propellers my dad designed were silicon bronze.

I thought silicon bronze has zinc, not tin and thus is a brass alloy?

[GordMay]

Bronze and Brass are both ‘red metals’ [alloys]; along with copper, their common element.

Brass is an alloy, primarily composed of copper and zinc. However, other metals, such as iron, aluminum, silicon, and manganese are also added, to yield different properties.

Bronze is an alloy that primarily contains copper and 12% tin. Other elements, such as aluminum, arsenic, manganese, phosphorus, and silicon are also added, to yield different properties.
The word “bronze” will, typically, have a preceding modifier, that describes the type of bronze it is, by indicating the major alloying element[s].

Silicon bronze is a low-lead brass alloy, largely made up of copper [94–96%] and a tiny bit of silicon [2.5–6%]. Aside from those two elements, it, typically, contains trace amounts of other alloys, such as tin, manganese, iron, and zinc.

[boatpoker]

Originally Posted by s/v Jedi

I thought silicon bronze has zinc, not tin and thus is a brass alloy?

Brasses and bronzes are classed by the amount on zinc in them. Brasses have 35 to 40% zinc. The many various bronzes have about 2 - 10% zinc

[s/v Jedi]

Originally Posted by boatpoker

Brasses and bronzes are classed by the amount on zinc in them. Brasses have 35 to 40% zinc. The many various bronzes have about 2 - 10% zinc

It appears this depends on interpretation. Bronze is copper with tin according to my info and it seems Gord reflects that in the post above as well.

[boatpoker]

Originally Posted by s/v Jedi

It appears this depends on interpretation. Bronze is copper with tin according to my info and it seems Gord reflects that in the post above as well.

It sort of is interpretation and there is no world standard, but it is what is taught and accepted in metallurgy.

[GordMay]

The International Copper Association:
Copper Alloys ➥ https://internationalcopper.org/sust...es-and-alloys/

[s/v Jedi]

Originally Posted by GordMay

The International Copper Association:
Copper Alloys ➥ https://internationalcopper.org/sust...es-and-alloys/

Yeah, it says bronze is copper with tin and brass is copper with zinc.