topic 35277
On average, how long can brass stay totally submerged in water?
A discussion started in 2005 but continuing through 2019
2005Q. I am in 11th grade, and I am doing research on brass for a novel, and I have some questions. I found this website, and read a posted question about brass, but I have a couple more questions to ask. First, How long can brass be left totally submerged in water? (this would be lake water or water in a stream). Can it be left in for -days? -weeks? -months? -years? Also- Does Brass rust after being left in water for long periods of time. If you can help me with this please post a reply. Thank you.
John B.student - West Bend, Wisconsin
2005
A. Brass does not rust, only iron-bearing materials will rust. Brass will corrode however. There is no good answer to your question as it will depend on the quality of the water. If completely submerged in a clean stream or lake that does not have a lot of offending materials like a low pH or sulfides and etc, it will probably last for many years and only slowly grow a corrosion layer.
James Watts- Navarre, Florida
2005
A. Sorry to be evasive, but the lifetime of brass will depend on a lot of factors, not least of which is what type of brass you use. Furthermore, there will be a major dependence on the chemistry of the water. Brass can undergo "dezincification", when the zinc dissolves out of the brass to leave behind spongy copper. This not only changes its appearance, but also significantly weakens it. The rate at which the zinc is removed will depend on factors such as oxygen content, pH, chloride levels, temperature etc. In an extreme circumstance, attack on the brass could be evident in a matter a few days.

Trevor Crichton
R&D practical scientist
Chesham, Bucks, UK
2005
A. As above, lots of factors involved.
But you need to know which copper alloy is to be submerged, and what the environment down there would be.
Consider bronze (copper and tin mainly) (not brass - copper and zinc mainly) cannons lifted relatively intact from sea bed after hundreds of years (cannons often in low oxygen conditions of silt/mud.
Trevor is right, brass is worse and would dezincify, especially in contact with other metals, ask any marine engineer or sea-going boat owner.
For lakes and rivers (presumably both fresh water), corrosion rates would however be much lower.
Regards
Marine Industry - Plymouth, Devon, UK
February 5, 2009
Q. In your opinion, how long could brass be kept in a stone box and buried in the earth before it began to corrode? How long would it take for it to corrode altogether? Thank you.
Barbara LeFevre- Dover, Delaware
February 18, 2009
Brass pins have been unearthed in the Philippines that are estimated to be from 2000 B.C., Barbara. If you search for articles about historical brass artifacts, you'll get some additional ideas. Please try to describe your actual situation -- not only because the exposure conditions could vary from horrendous (mine water intrusion?) to highly benign (absolutely dry?), but because readers tell us they enjoy responding to human interest situations but they dislike flash quiz style questions :-)
Thanks.


Ted Mooney, P.E.
finishing.com - Pine Beach, New Jersey
Striving to live Aloha
September 13, 2011
Hi, I have a 14" tall Carp Fish decor made of brass. I plan to place it above the catch basin of the waterfalls leading to my fish pond. Doing so will partially submerge the bottom of decor (2") under water. It will also be exposed to sun light. I live in the Philippines where temperature ranges from 28-37 degrees F whole year round with frequent raining & typhoons.
Q1. Should I go ahead and do it or should I display it somewhere else, i.e., away from water and sun?
Q2. Is there anything I can do to protect the decor from deteriorating? I read somewhere that even the clear lacquer protective coating will peel off under water.
Q3. The hardware store sells Elastomeric (sort of rubberized) coating for sealing roof leaks. Is it advisable to coat the bottom part of the decor to protect the portion that is submerged under water?
Any advice will be greatly appreciated.
pond hobbyist - Quezon City, GMA, Philippines
November 14, 2017
Q. Hello all. This is a related brass/bronze question. I'm writing a novel in which an artifact from a sunken ship comes into play. I was imagining something made of brass, bronze, or copper. The shipwreck area is Lake Superior, which has a temperature ranging from 32-55 degrees F (0-13 degrees C). The depth of the wreck is at my discretion, as this is fiction. However, I like to be as accurate as possible.
1) What kind of damage might such an object sustain (due to the cold fresh water) over a period of 100-200 years? (Tarnish, corrosion, etc.)
2) How thick/heavy would an item need to be remain intact at a depth of 100 feet? I had considered using a wooden box with metal components, but I feel that might deteriorate significantly.
Thanks for your help!
- Denver, Colorado, USA
A. Hi there. I was just at the Athenian Archeology museum researching this very issue. They have several recovered sculptures in marble and brass with extreme underwater (fresh and sea water) corrosion. I sent some images to this finishing site:
Best
Raphael
Artist - Brooklyn, New York. United States
November 22, 2017
A. Two small thoughts
Until probably the 19/20 century "Brass" commonly referred to Bronze. Hence 'Brass cannon' are invariably bronze a copper tin alloy not copper/zinc brass.
Secondly, you might like to look up 'antikythera mechanism'
Images and fascinating videos of reconstruction - and food for thought for a writer.

Geoff Smith
Hampshire, England
May 15, 2019
Q. Hi I found a pot buried in my back garden. It must have been buried for at least 20 years. I cleaned it up and now it is sparkling. It looks like brass. Is this possible or should it have corroded more?
Oscar HanlonMs - United Kingdom
May 17, 2019
A. Hi Oscar,
Corrosion rates are affected very much by soil moisture and chemical characteristics, so there's no good answer to your question. One interesting tidbit, though, is that for many metals, the oxidation layer on the surface actually protects the substrate from further oxidation~ think of the 'verdigris' you see on statues. There's even a type of steel that was engineered to rust itself a nice protective layer and then stop! But even that is subject to environmental factors, and if it's damp and salty enough, all bets are off.

Rachel Mackintosh
Plating Solutions Control Specialist / Industrial Metals Waste Treatment - Brattleboro, Vermont
September 8, 2019
I have what looks like a brass button for overalls. I found it in a spring close to Lake City off the Swanee river. It was on an old civil War wreck. It was green on the back when I brought it home in 1970. The green fell away and it is in perfect shape.
- Brunswick, Georgia USA