Black oxide setup

Make up your solution at concentration so that the level is 6 inches down from the top of the tank. Fix a horizontal pipe down 4" from the top with holes drills to squirt water at a 45 degree angle against the side of the tank.

When the solution boils off water and goes up to , then the motorized valve will come on an automatically add water, as the temp drops to , then , all the time while still boiling, then the motorized valve will close. Your concentration will be automatically controlled. As you drag out solution the level will drop to 7" down, then 8" down. Then the operator carefully shovels in more salt, still boiling, and the water automatically comes on and raises the level to match the amount of salt he added.

Robert Probert offers what appears to be sound advice based on long experience. People have been killed by black oxide solutions in this way. So you must exercise great care that there is no possibility of introducing water down into the bulk of the solution. I have designed all kinds of metal finishing equipment, but I have not and will not design a black oxide tank because of concern over this possibility and always suggest that shops purchase black oxide tanks from specialized, experienced constructors.

Thanks for the information, Mr. Probert and thanks for the warning Mr. Mooney, I am aware about the possibility of solution eruption thanks to the many articles in finishing. I guess Mr. Probert has given a hint on how to do it correctly and somewhat safely. Unfortunately, I live in a place where equipment supplier that specializes in plating is rare, and none that I know of for black oxidizing equipment.

So I guess I just have to be a bit creative. The main advantage of having rinse tanks made of stainless steel is they will not rust like plain steel tanks which form small particles of rust in the rinse water that could stain your final black oxide finished parts. Why suffer from undependable equipment or homemade tanks when a complete factory-produced installation is available — at a reasonable price from the most trusted name in black oxide finishing today!

This system will pay for itself in increased business and ease of operation in no time! The system will have a heated soak cleaner tank, heated black oxide tank, and two water rinse tanks.

Tips and Resources. Select what type of metal you are blackening. Cast Iron Steel Stainless Steel. The hot black oxide is truly a better, more durable, higher-performing coating. The one area where I would preferentially use room temperature black would be on castings, forgings, and powdered metal.

The difference between the two products when it is all said and done is the Black Magic Infusion has a little bit higher surface tension so that when you use that product, you tend to drag out more solutions with the parts as they exit the black bath into the rinse.

So black magic infusion helps to alleviate that problem. There was a situation where I was blackening a gator clip, and I came out of the hot black oxide water, rinsed it, and as I came out of the rinse, the parts actually fractured and broke because of the hydrogen buildup in it. Generally speaking, the harder the alloy — say if it is a spring made out of piano wire, for instance, or those gator clip type parts — could be very prone to hydrogen embrittlement.