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Copper cupola over bay window ruined by brick acid wash

2003

We completed building a home in March 2001. Just prior to completion, the builder acid washed the brick above our large copper bay without covering the bay. This is a large bay on the front of the house just above the dining room. It is not the type of copper that remains shiny but the type that naturally weathers. The copper bay was immediately grossly streaked and spotted when the brick was acid washed and it has never looked any better nor has it formed the natural patina. The copper bay above the dining room is also grossly rusting. In comparison, we have a second copper bay area above the master bathroom. It has weathered naturally and looks fine. The brick was not acid washed above this bay.

I would like to ask:

1. What do I need to ask the builder to do in order to repair the copper bay above the dining room?
2. Can it be restored so that it will weather normally and acquire the natural patina?
3. If it can be restored:

a. What are the best materials to use for its restoration?
b. What is the restoration process?
c. What is the cost of the materials and labor?
d. Will the natural patina form after restoration?

Thank you,

Ivy Lalonde
Consumer - Knoxville, Tennessee, USA

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2006

What is the answer to the question about the acid stained copper cupola?
I have the same problem with the flashing on my house and I can't seem to find an answer to how to restore it.

Thank you,

Marianne Pearsall
- Crystal Bay, Nevada, USA

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Copper does not and cannot rust, Ivy; if you are seeing rust, something is very wrong, like your roofing being copper plated steel instead of solid copper. If it is rusting it cannot be saved or restored.

If it is solid copper, after the staining has been washed away there is no reason it should not begin to take on a patina. Copper polishes are designed to clean copper and they should work. If the staining is too deep you could try cleaning with vinegar ⇦in bulk on eBay or Amazon [affil links] plus salt or lemon juice plus salt. This is very aggressive and will leave the copper a pinkish or salmon tone that you won't like, but either time or a standard copper polish should bring it back on key after a while (but try on a small inconspicuous area first).

Again, if it's copper plated, really aggressive cleaning might ruin it.

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey