Aluminum is unique among other metals in a sense that in addition to its naturally forming thin barrier oxide, anodizing This aluminum is in good shape, I’ll use 400 grit in case the surface is mildly uneven. Top Specs for Coatings on Metal Top Specs for Coatings on … Two of the most popular are silver and aluminum. The simplest optical coatings are thin layers of metals, such as aluminium, which are deposited on glass substrates to make mirror surfaces, a process known as silvering. The first tin-coated glass mirrors were produced by applying a tin-mercury amalgam to the glass and heating the piece to evaporate the mercury. Though each plating process has its differences, both aluminum and silver coating can offer unique benefits that improve the functionality of optical mirrors. Tin. The multi-layer film also provides the improved … Most expensive is gold, which gives excellent (98%-99%) reflectivity throughout the infrared, but limited reflectivity at wavelengths shorter than 550 nm, resulting in the typical gold colour. Durability and reflectivity are the most important characteristics in the choice of the coating. We’re making your quote process easier and faster with our series of Tips on how to request a quote. From gold and zinc to copper and platinum, many metals can be used to coat mirrors. Aluminum Coating Properties and Treatments Anodizing is a common electrochemical process used to grow an oxide film on the aluminum metal surface for enhanced protection. A large plastic tub that’s about 25% larger diameter than the mirror. Available Types from AccuCoat: Aluminum mirror coating (Al), Gold coatings (Au), Silver coatings (Ag)Chrome coating (Cr), Dark Chrome coating, Copper coating (Cu), as well as Inconel, Nickel (Ni), Titanium (Ti), and All Dielectric coating. Gold The metal used determines the reflection characteristics of the mirror; aluminium is the cheapest and most common coating, and yields a reflectivity of around 88%-92% over the visible spectrum. In an Enhanced Aluminum coating, a multi-layer film of dielectrics on top of aluminum is used to increase the reflectance in the visible or ultraviolet regions. An important part of the manufacturing process is the quality control of mirrors. This process gives the mirror the ability to focus as well as reflect light. Cooling the strip; Top coating on one or both sides; Second curing ; Cooling down to room temperature; Rewinding of the coated coil . Watch The Video > This coating is ideal for applications requiring increased reflectance from 400 – 650nm while the UV and DUV Enhanced Aluminum coatings yield increased reflectance from 120 – 400nm range. Metal plating is the most common form of mirror coating. Pre-soak the sandpaper, wet the piece down, and then continue to sand. The kind of coating to be used is specified by the mirror design. The following steps take place on a modern coating line: Stitching the strip to the previous coil; Cleaning the strip; Power brushing; Pre-treating with chemicals; Drying the strip; Applying primer on one or both sides; Curing (often only 15 to 60 seconds!) Baking powder to neutralize the used ferric chloride. Some mirror makers evaporate a layer of quartz or beryllia on the mirror; others expose it to pure oxygen or air in an oven so that it will form a tough, clear layer of aluminum oxide. Ferric chloride for stripping an old aluminum coating. More expensive is silver, which has a reflectivity of 95%-99% even into the far infrared, but suffers from decreasing reflectivity (<90%) in the blue and ultraviolet spectral regions. If it’s a flat piece, use a rubber backer, for contoured areas, a foam pad can be used as a backer instead which is what I used for polishing my wheels.