IonBond DLC
IonBond DLC (stands for Diamond Like Carbon) is a hard black finish that is fairly new to the firearms market. It is a is a physical vapor deposition coating that has a 3-6 micron build up per surface (that's less than .005"). DLC can be applied to carbon steel, stainless steel, aluminum, over polished surfaces as well as matte surfaces. When bone-dry it is a dark charcoal color. With a little oil on it, it's black. It's hardness runs 70+ on the Rockwell "C" scale. I think it's the best all around option for a black firearms finish. It appears to be the equal to hard chrome in the durability and rust resistance departments. Black-T might be a better choice if rust resistance is the main criteria, like working in a salt water environment with no care given to wiping down every day or so, but in a less hostile climate or one with more care given, rust is a non-issue. There are a couple of peculiarites with DLC. It requires that the part be able to conduct an electrical charge, creating a problem in coating anodized aluminum. Anodizing is an insulator. If the aluminum is bare, it can be successfully coated with DLC. Type III hard coat anodizing might be a better choice for your aluminum frame than DLC in this respect: DLC (and hard chrome, too) is a little like an unpeeled hard-boiled egg. The exterior is fairly hard and tough, but because of the relative softness of the interior, that coating (or shell) is also a little bit brittle. Should an aluminum-framed pistol coated in such a manner be dropped and dented, the coating's adhesion with the substrate may be compromised. I don't consider that to be a huge deal. I understand that I've already made a compromise by selecting an aluminum frame to start with. I understand that aluminum is easier to dent than steel and I accept the risk. Anodizing penetrates the surface of the aluminum as well as building up the exterior. I'd recommend finishing your Lightweight Commander, for example, with Type III anodizing on the aluminum parts and DLC on the steel ones, getting the best of both worlds.
Another unique feature to know about DLC is that the shape of the part can have an impact on how the PVD process coats the part. For example, the shape of beavertail grip safeties can sometimes cause a faint, narrow "stripe" to be seen on the back side of the safety, where your hand goes. It changes appearance somewhat, due to light and the presence of oil. It is an anomaly that the IonBond people are trying to solve, but still shows up from time to time. I mention this because some guys after learning about DLC, get the idea that DLC is the modern day replacement for bluing and is superior is all regards. Well, it's not.
Bluing is a process where the parts are submerged in the salt bath and all surfaces are equally coated. The process for applying IonBond DLC requires that each part be tied to a wire that is hung from a fixturing tree after which a vacuum is drawn in the chamber and the atomized molecules are transferred through the vacuum to the negatively charged part being finished. It’s possible for a tiny speck of gray dust to land on a part at just the wrong time and a tiny white spot can occur. It’s something that IonBond works hard to avoid, but has been known to happen. If it does, the only thing that can be done is to abrasive blast the part until the finish is entirely stripped (which leaves the metal in a rough matte texture), then sand any polished surfaces back to whatever level they are supposed to be and send it back to IonBond to be recoated. IonBond will recoat the part at no charge. Were this a blued part, it could just be dipped a second time in many cases with no additional prep work. I will charge for any prep work involving sanding and any additional roll mark restoration needed. For this reason, I really recommend only doing matte IonBond finishes.
While DLC comes close to matching the appearance of bluing, it's not quite the equal in it's ability to have a consistent, uniform color, regardless of the shape of the part or the direction of the light. It also doesn't reflect light the same as bluing. It always looks a little hazy, just because it doesn’t reflect light the same way. If you're selecting a finish for your family heirloom, presentation grade pistol, where appearance is the chief concern, bluing is still the King. If you want a best of breed, black finish that excels in many areas and when durability is really important, DLC is the good stuff
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