How To Correctly Buff and Polish Brass
First, let's talk about what brass is. Brass is made up of one-thirds of zinc and two- thirds of copper, making it a metal that has a gold color to it. Since it is made up of two-thirds of copper, brass can turn into a green hue after being exposed to different weather after a period of time. Along with turning a different color than its original state, brass can also darken or become lifeless. After reading this article, I can assure that you will be able to turn the lifeless brass into a shiny and new surface while also maintaining its life for longer.
The number one thing to do when starting this buffing and polishing process is to make sure you are cleaning the brass efficiently beforehand. Brass can collect dirt, oil, and grime overtime : it is important to remove the debris first in order to get the best possible end results. To clean the brass, you can use a variety of items. If you need something fast, warm water and soap will do. However, there are many products on the market that are made specifically for these jobs. A metal polish or an All Purpose Cleaner will be your best friend in these instances due to the fact that they contain certain ingredients and chemicals that soap don't -- which will strip the unwanted debris perfectly. These items will work especially well if the brass you are working on is very old and starting to flake or peel. Make sure to let the cleaner soak into the surface for about a minute before wiping it off with a clean microfiber towel.
After cleaning the surface thoroughly, we can begin to sand the brass. A necessary thing to do before you start sanding is to see how damaged the brass is. You will need a lower grit of sandpaper (more rough) for more damaged pieces in order to strip the tough material. A higher grit of sandpaper is best for brass that is not as damaged and does not need much material to be stripped because higher grits are a lot finer. It is recommended to start with a 320 grit sandpaper if the surface has some damage, and make your way up to an 800 to 1500 grit. Also, wet sanding can be very helpful when sanding brass because it maintains a smooth surface and helps keep sanding debris and dust from getting out of hand. It is important to stay away from having a heavy hand while sanding -- it will cause scratches which is not the goal. If the surface you are working on is larger, a power tool can be much more efficient and easier for you in the long run.
The next thing that will get you a beautiful finish on your brass is buffing. Airway buffing wheels will get the scratches that you couldn't get out in the previous sanding step. Along with the buffing wheel, a buffing compound is going to be needed for this process as well. Buffing compounds will ensure a nice shine and great finish on the brass. A compound with little abrasives or even no abrasives is best to use to avoid scratching the surface this far into the process.
A black buffing compound is best for buffing and cutting unwanted scratches or material from the surface due to it being somewhat wet and slightly sticky. After you use the black buffing compound, remove the remaining product that is just sitting on the surface with a microfiber towel. You would then want to go in with a brown tripoli compound with a looser buffing wheel -- such as the yellow or white one -- making sure to wipe it after with a microfiber towel. At this point, your brass will look shiny, however, following up with a green compound will give a mirror-like finish (continue with the yellow or white buffing wheel).
You may be wondering how to actually use a buffing compound bar. The correct way to use it, is by spinning the airway buffing wheel against it without putting a lot of pressure on it. The reason you do not need a lot of pressure is because as the buffing wheel spins, it will create heat causing the compound bar to transfer onto it. Brass is somewhat easier to buff because you can use different compounds (depending on the outcome you are looking for) to make it new again, whereas other metals require certain compounds.
Once you get the compound bar product onto the buffing wheel, you can start to actually buff the surface you are working on. At this step, you will want to use light pressure and a downward motion -- remember to switch to a new buffing wheel if you start to use a different compound bar to avoid unnecessary scratches. Once you have finished with the buffing stage and you have wiped the surface with a microfiber towel, it is time to properly protect the brass.
If the brass you are working on will come in contact with a lot of individuals and their hands, it may be smart to add oil -- such as mineral oil -- to protect its life for longer. A spray lacquer can be used if you are refinishing a previously lacquered brass, which will give it a great shine