Brass Maintenance Beginners Introduction of Maintenance Agents (Materials)
Brass is an alloy of copper (Cu) and zinc (Zn). The base material is originally a platinum gold color, but the copper component changes color when it comes into contact with moisture and oxygen, gradually turning into an antique gold color.
Personally, I think that both the new platinum gold color and the aged antique gold color are attractive, but there are many cases where the color does not change as desired due to the delicate nature of copper alloys, so we recommend using brass materials. I would like to write about maintenance.
There are many maintenance agents (materials) for brass and copper products, but since they are functionally similar, we will introduce some easy-to-use maintenance agents (materials) recommended for different finishing applications.
[I want to leave the texture as it is and return it to the base color]
Acid Cleaner HALT
Manufacturer: Orb Tech Co., Ltd.
https://www.orbtech.co.jp/halt halt/
A cleaner that has recently become a common sight at home centers, etc., with the catchphrase used by the US Navy. Since it is based on phosphoric acid, it is less prone to dezincification (a state in which copper components come to the surface) compared to other acidic cleaning agents. . There is also a spray type and it is very easy to use as a feeling of use.
Brass and copper alloys instantly remove oxide films and dirt, so wash with water as soon as you can apply evenly. If brass and copper alloys are exposed to chemicals containing acids or alkalis, they will change in a short time, so it is important not to leave them for a long time.
[I want to polish beautifully / I want to give gloss]
picard liquid
Manufacturer: Nippon Abrasive Industry Co., Ltd.
https://www.pikal.co.jp/archives/330
The most popular emulsifying liquid metal polish in Japan. It is a simple action of physically polishing by applying a liquid abrasive to a waste cloth. Since it does not cause chemical changes to metals such as brass and copper alloys, the finish is stable. In addition, there are sizes from 180g, which can be purchased relatively cheaply and can be used for a long time, so it is a product with high cost performance.
By changing the cloth to a brushed towel, it can be used on uneven surfaces. Since it is viscous, liquid tends to remain on the surface if it has a large surface. It is easy to remain on small parts such as engravings. It is also possible to adjust the amount of abrasive by diluting it with water beforehand to moderately reduce the glossiness of the finish and make it easier to wipe off. We recommend wearing rubber gloves (nitrile rubber if you have them) as your hands will get dirty.
[I want to remove dark and deep discoloration, dirt, and scratches]
Recobrite Hand Pad (Nylon Scrubber)
Manufacturer: Riken Corundum Co., Ltd., etc.
https://www.rikencorundum.co.jp/product/detail/29
For discoloration and dirt that cannot be removed with the above cleaners and abrasives, the most recommended method is to physically scrape off with a nylon scrubbing brush. There is also a method of removing it with strong acid, but many of these chemicals are similar to so-called powerful drugs and generally cannot be used without specialized drainage equipment, and of course they are difficult to obtain, so they are excluded. On the other hand, so-called nylon scrubbing brushes like the one above are readily available and easy to use because they are manual. It has the image of a fibrous file, and there are as many types of sandpaper as there are types. Fortunately, brass and copper alloys are not very hard, so it is easy to physically scrape them off.
*Please note that the plating will peel off if it is plated rather than bare.
Recobrite hand pads and 3M Scotchbrite are typical, but both are mainly for corporate demand, so they often have a large capacity (many sheets). It is more convenient to procure it there because you may be able to buy it from one piece including similar products at Monotaro and home centers. Abrasive material is generally aluminum oxide, and its hardness is high enough to polish glass.
In addition, most DIARGE staff use a number between #150 and #1500.
If there is discoloration or dirt, polish with #400 to #800, and lightly finish with #1500.
For shallow and fine scratches, use #400, and for deep and large scratches, gradually increase the number from #150 or #240.
File marks do not disappear completely, so flat plates (especially those with large surfaces) should be polished in one direction. In either case, if you polish it lightly with a picard, the file marks will not be noticeable and the platinum gold color will settle. If the file is left strong, it will look whitish depending on the amount of reflection. As an application, it is also possible to create a texture similar to barrel finish or vibration finish by randomly finishing the file.
It is possible to maintain most brass and copper alloys with any of the above maintenance agents (materials) or in combination.
I would like to write a separate article about the maintenance of DIARGE items.