How to Clean Your Metal Sign

By Dan Matthews

Metal Sign Cleaning and Maintainance

Painted metal or tin signs are harder clean, and the paint is less forgiving than porcelain. So it's important to be careful when cleaning these signs.

WARNING: Do not use warm or hot water, this will sometimes discolor and dull a painted sign.

Here are my recommendations. Note that your results may vary.

How to Clean an Antique Metal Sign

The first thing to use is cold water and dish soap.

Gently cleaning with cold water and a mild dish soap usually will be enough to clean most signs. You can use a gentle (not agressive) car wax on a metal sign. Maguire's #4 car wax is what I use.

However, if your sign needs more cleaning, here's what I recommend:

This is important: always test the cleaning product on a small area at the corner of your sign before the center of the design. You can try Simple Green, Windex or Goop hand cleaner. But do not use the one with Pumice. And DO NOT use Mean Green -- it will take the paint off of metal. Do not use Fantastic or any very aggressive cleaner.

Once you've tested the cleaner on a small area, gently expand to clean the entire sign.

If your painted sign is starting to flake or the paint is coming off, you need to clear coat it.

Now, do not spray a lot of clear coat. Just apply a light spray coat once or twice. You can also use “Boiled Linseed Oil” not plain linseed oil. When doing this get a paint sponge or brush, applied in one direction. Only do one application at a time, and let it dry completely. It may take a few days to dry.

Displaying your Metal Sign

After cleaning, some people like to back their small signs mount them to keep them from flexing or put them in frames to protect the edges. Backing or framing will not hurt the value of the signs It keeps them from getting damage so it can preserve their value.

Larger signs usually are self-framed or have wood framed back to protect the sign.

To best preserve your painted tin signs, keep them in a climate-controlled building where the temperature and humidity are kept in a certain range. If you can't keep them in a climate-controlled building, you should know that the wide change in temperatures may cause the paint to peel from the sign. A room that is too humid will cause the sign to rust.

Repair and Restoration Tips

Should I hire a restorer or try to fix a metal sign myself?

Only restore a sign that has a high value or is extremely rare. You will never get your money back on a common sign. You are just better off to find one in good condition.

I always make the comparisons of should you restore a 1966 Ford Mustang Coupe or restore a 1966 Ford Shelby Mustang? You would get your investment back on the Mustang -- but never on the coupe.

When having a sign restored first find a reputable restorer. To me it is better to touch up a sign than to restore it, unless it is in treble condition.

What should I do about the nail holes in my metal sign?

Nail holes are common in antique metal signs. Smashing them will make them look better, but it could knock the paint off, which lowers the value.