Clean brass has a bright, golden brown appearance. The most similar metals in appearance are copper, which is brown or pink-brown, and bronze, which is a much darker brown. [1] X Research source Brass is slightly magnetic, but should only respond noticeably to a powerful magnet. If a small magnet sticks firmly to the surface, you probably have an object made from a different metal, then plated with a thin layer of brass.
Wear rubber gloves and work in a ventilated area to avoid inhaling fumes. Let small objects soak in the acetone. Use a paintbrush to brush the chemical onto large objects. Be sure to coat every corner of the object. Methyl alcohol, paint remover, or lacquer thinner will also do the job.
Check to make sure there is no remaining lacquer. Modern brass objects are often protected with tough lacquer that can take several attempts to remove entirely.
Wear gloves even when using these skin-safe cleaning products, since oils from your hand can get on the brass and prevent the antiquing effect from taking place evenly.
Be cautious when applying heat to a brass object that recently had its lacquer removed. If you missed a piece of lacquer, it could catch on fire or release fumes. Dry the brass in a well-ventilated area with no flammable objects nearby. You can now use any of the methods described below. If you’re unsure which to use, read the first step of each one to learn the benefits of each option.
Prepare the brass first as described above to ensure the antiquing succeeds. Wear rubber gloves for any method to prevent getting oil on the brass.
Mix a spoonful of table salt into the vinegar for a greener patina. Heating the brass with a hair dryer or oven to around 450ºF (230ºC) will produce more noticeable results, but you’ll need oven mitts or thick gardener gloves to handle it at this temperature.
Pour some vinegar into a plastic bucket with an airtight lid. Place wooden blocks or other objects into the bucket so a stable, flat surface is dry above the level of the vinegar. Place the brass on top of the objects. Seal the lid to trap the vinegar fumes and let them alter the brass for several hours or overnight.
Once it is dry, you have the option to preserve its color by coating with a brass lacquer or wax.
Always follow the instructions for Preparing Your Brass before beginning any antiquing method. This is not a good method to follow if you’re not certain that your piece is solid brass. See Using Vinegar or Salt Water instead.
Be especially careful if your product contains any of these hazardous chemicals: ammonium hydroxide, glacial acetic acid, nitric acid, or sulfuric acid.
Do not use container made from other materials, as the acids in the solution could corrode them. Do not fill the container too full. Leave room to fit the brass object without the container overflowing.
Air bubbles that remain on the brass will cause bright spots where the brass was not aged. Turn the brass object in your gloves so you get even exposure to the solution.
If you plan to brighten your object with highlighting (see below), let it get slightly darker than the color you want. Don’t worry that you’ll ruin your brass. If you pulled it out too early, simply put it back and shake again. If you pulled it out too late, scrub with a scotch-brite pad or lightly with steel wool to remove the color so you can try again.
If you are trying to create a black or almost black patina, you’ll have better results getting the patina to stay if you dip it in two or three stages, rinsing between each one.
Ammonia will eventually evaporate off the brass, so you’ll need to commit to repeating this process every time your brass returns to its old appearance. How long this takes depends on the exact qualities of your object. This process will not succeed if you do not follow the steps for Preparing Your Brass beforehand.
For tiny pieces of brass, you can use a glass bottle with airtight cap instead of a bucket. Tie it with a cord and suspend it over a small amount of ammonia, screwing the cap firmly to hold the cord in place and trap the ammonia fumes.
Open the lid slightly for a quick glance, then close it tightly to keep most of the ammonia fumes in.
The aging effect of ammonia is only temporary, so you probably don’t want to lacquer the brass since you would eventually need to remove the lacquer to re-antique the brass. You can use the same ammonia bath to treat other brass objects, but not indefinitely. Eventually the ammonia’s potency will be used up and you will need to replace it.
