Materials: Difference between revisions

[[File:Materials.jpg|thumb|Flashlights made of (from left to right): anodized aluminum, titaninum, and stainless steel]]Anodizing is a process of oxidizing the the surface of aluminum (usually, for flashlights) to provide a surface that is more resistant to wear and corrosion, while also providing a better surface for coloring. Better flashlights feature Type III anodizing (also called hard anodizing, "HA," or kind of redundantly, "HA III") which provides a thicker, less porous coat of aluminum oxide that is more deeply embedded in the base aluminum than Type II anodizing (there is no such thing as HA II, all hard anodizing is Type III). The anodizing is done by using the aluminum as a positive electrode (anode) in a bath of sulfuric acid. As oxygen forms on the anode, a coating of hard aluminum oxide is formed on the surface. Aluminum oxide is very tough material, in fact it is the grit that is on most sandpaper. This coating increases the thickness of the aluminum and is integral with the aluminum itself and therefore is resistant to chipping or peeling. Coloring is added later (supposedly not many dyes can be used with HA III which is why flashlights are either natural or black, but HA III flashlights have been showing up in a lot of different colors lately). See [http://en.wikipedia.org/wiki/Anodizing Wikipedia Anodizing] for more information as well at this [http://www.candlepowerforums.com/vb/showthread.php?t=174901 CPF thread].