Polishing

Polishing is a smoothing finishing process for different materials. The smoothing effect is usually achieved by two mechanisms. For a roughness peaks of the surface structure are plastically deformed and partly plastic and so paved (also press polishing, Burnishing engl. ). Secondly, depending on the nature of the polish a micro to small material removal ( smoothing ), as well as the filling of depressions. The reaching surface is often due to the glossy smoothness.

According to DIN 8589, however, polishing is not an independent manufacturing process, but is only used in conjunction with other procedures such as buffing, Polierhonen or electrolytic polishing.

Abrasives and polishes

In the conventional polishing the removal and smoothing of the surface with very fine polishing agents such as Polierrotkuchen, polishing slate, chalk, stannic oxide or cerium oxide, which are usually bound in a paste or liquid, sometimes called polishing is done. The agents are in a polish carrier, such as a cloth, felt, rubber, pitch or leather wheel for rotating process or cloth for vibrant works, bound or applied to the surface.

Manual polishing means objects or surfaces with a soft cloth or a soft brush after cleaning, often with the aid of chemical additives to rub off, so that they shine. This applies, for example, wood floors, furniture or leather shoes with shoe polish.

Metal

Editing is done in most metal machine with rotating polishing wheels made ​​of fabric, felt or leather. On the disk, the so-called polishing agent carrier, the actual polishing agent is applied either as a suspension or as a so-called solid paste. The polishing agent is composed of different greases, oils and the actual polishing agent. This may be, for example, alumina, aluminum oxide, chromium trioxide or the like.

Electrolytic polishing

The electrolytic polishing allows metal parts (eg, stainless steel, brass, aluminum alloys, and others) to clean, deburr and bring shine. In this case, the metal is immersed in chemical baths (electrolytes ) and a DC exposed.

Wood

The wood is initially cut and then coated with a lacquer. After painting take place a plurality of intermediate sections and a further application of coating to obtain a closing of the pores and a smooth surface. At the end of this process, the actual polishing is carried out by means of a rapidly rotating buffing wheel or on the belt sanding machine with the help of a rapidly across the surface moving Schwabbelbandes.

If shellac used for polishing, one also speaks of a French polish that is applied with a bale. As the abrasive horsetail or pumice is used here like that fills the pores in addition. Since dealing with shellac is not easy and very labor intensive, it is used only in the restoration of old furniture and very high quality musical instruments.

Another traditional method is the oil polish. However, it was used only briefly in furniture manufacturing. Because of this and also due to improper restoration concepts almost no objects are preserved. Here, linseed oil is applied as a coating in multiple layers and with various abrasive materials, thus achieving a smooth surface.

Stone

For polishing of flat stone surfaces to use wood frame or wood panels which are covered with leather or felt and weighted with lead weights. While the slab to be machined is secured in a gypsum bed, the set on the grinding stone frame is moved back and forth, whereby between the workpiece and the grinding surface of quartz sand is washed, until the stone has a smooth surface. Then maybe another cut with continually finer sand or emery.

More levels finer grinding done with the addition of stannic oxide geschlämmter or triples, one imported from Africa clayey sediment, as well as the finest rock flour and water. Matte finish is achieved by polishing with white wool, mirror-like shine last. Finest by dry stannic oxide Small works of art and decorative items are processed on lathes and grinding small tables.

Plastic

Plastics such as polymethyl methacrylate (Plexiglas ) are usually polished by various fine abrading and subsequent treatment with so-called polishing paste or different fine polishing waxes. The easiest and fastest way to polish small areas, such as cutting edges, is along strike with an acetylene flame. The flame should be as rich in oxygen burn to avoid soot formation. The heat melts the material surface and a smooth surface cools off again. The surface is polished. Disadvantage of this method are strong internal stresses in the material which can manifest themselves as fine cracks after some time. Is further promoted the cracking caused by cleaning agents containing alcohol.