Steps to clean a bronze ground marker
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© Cotner Monument LLC 2012
Clean a Bronze Marker
All actions taken based on advise of this web site are done so at the sole risk of the person conducting the cleaning. No responsibility is assumed for any damage to a monument as a result of the advise given on this web site.
Evaluation of a bronze
marker and warnings
on the pitfalls of
Bronze markers are made of bronze
metal. Bronze is a mixture of copper
and tin in about 9 to 1 ratio. Bronze is a
relative hard metal but is very brittle. A
bronze monument can be easily broken
with only a minimal amount of force.
Bronze was probably the first wide
spread composition metals with its
common use beginning around 2.500
A bronze marker is made by casting the
base monument. At this point, the design
and lettering are cast into the monument.
The monument is them trimmed by
hand, some areas polished and given the
background paint. The monument’s
lettering is them surfaced so they are flat
and polished. Finally, a protective coat
is applied to the whole monument. The
protective coat is designed to slow the
oxidation of the monument. At this
point the bronze portion of the
monument is complete. The monument
is them attached to a granite base. The
granite base provides the support for the
The aging process of a bronze
monument occurs in two stages. The
first stage occurs as the protective
coating begins to ware. Although many
advances have been made to improve
the longevity of the protective costing,
over time it will ware off. The second
stage occurs once the protective coating
has worn off. The copper in the bronze
begins to oxidization. This is similar to
rust on a piece of steel. Oxygen
combines with the copper to form
copper oxide. As opposed to rust on
steel, the oxidization does not harm the
bronze. In fact, the oxidation forms a
protective layer. The oxidation can take
a dark brown to green appearance based
on other chemicals which can be present
as the oxidation occurs.
When cleaning a bronze monument, you really
have three areas to clean. First you have the
granite base. Second you have the polished details
which are primarily the lettering. And finally you
have the bronze monuments background and
decorative elements. Each surface has its own
issues to evaluate the cleaning challenges and
solutions to those challenges. Just to restate the
obvious. Cleaning a bronze monument is tricky
and you are most likely not to get good results. Use these suggestions at your own risk. I
strongly suggest getting a professional to help you out.
Again, the first step in cleaning any monument is to evaluate the condition of the monument.
Here are the steps to follow when evaluating the monument:
Look and see if either the granite base or the bronze monument is cracked or
broken. If so, locate a qualified monument dealer in the area to assist you with
the monument. A cracked base can be replaced easily at a minimum cost.
Replacing the base is important as it is the support for the bronze monument.
Poor support will result in the bronze ultimately breaking. If the bronze is broken
or cracked, the monument may be repairable. In many cases, the monument
cannot be repaired and will have to be replaced. DO NOT try to deal with this
type of problem alone. Get professional help. Both a monument dealer and a
bronze manufacturer can aid in the repair process.
If the granite is just dirty or stained, this is by far the simplest with which clean.
You should just refer to the section on how
to clean a stone monument on this web site.
I have a couple of additional comments
though on cleaning granite. Many of the
chemicals which you might use to clean the
granite will react with the bronze. DO NOT
use bleach or any household cleaner with a
high or low ph. These will damage the
bronze. Our recommended cleaner, D/2 is
chemically neutral and will not affect the
If the bronze is simply dirty, cleaning it is again simple. I recommend using a
mild dishwashing soap. Dawn dishwashing liquid seems to work very well. Use
a lot of water and a soft brush. Less soap is better as it is easier to clean off. Be
sure your rinse the monument well. Any soapy deposits left will result in a dirty
residue building up on the monument.
Now comes one of the tricky conditions for you to handle, tarnished letters. No
matter what you do, overtime, the letters will tarnish. The tarnish is called patina
and is considered by many to be attractive. But if you just insist on polished
letters, here are the steps to polish the letters. The best product is called “Brasso”.
It is a brass and bronze polishing agent. It is abrasive, so it will scratch the
lettering somewhat, but will remove the patina. Use the Brasso sparingly and
only on the top of the letters. The Brasso will remove the background paint, so
keep it off as much as possible. Once you polish the letters you will need to seal
them. If you just leave them as is, they will tarnish in a matter of weeks. To
reseal the letters, you can use a spray can of clear lacquer. You will need to seal
the whole monument so it appears consistent. Be sure you have cleaned off the
Brasso and the whole monument is free of dirt and grime. The other option, and
the better of the choices, is to remove the monument and have it professionally
refinished by one of the monument manufacturers. A professional job is the best
way to ensure that the monument is restored to its original condition.
In the paint on the background is peeling, you can repaint it. Several of the
companies which manufacture bronze monuments sell kits to repaint the
background. I have used the kits in the past and it is tricky to get good results.
DO NOT use some spray paint you get from the hardware store. This is not the
paint used on these bronzes and it will not work or last. Once again, you have the
option of a professional refinishing.