[Ron Wood]

The absolutely important thing to remember is ADD THE ACID TO THE WATER...SLOWLY!!...NEVER ADD THE WATER TO THE ACID!!! If you pour the water into the acid it will flash boil and explode. More than one student has learned this the hard way in the laboratory and got severe acid burns.

As I recall you mix the acids together and add the nails. After the nails have dissolved, add the mixture slowly to the water. You need to use a crock or glass vessel. After it is mixed thoroughly, put the final mixture in a dark glass bottle, sunlight weakens the bluing solution. Oh by the way, it is probably best to do this all outside...that stuff stinks.

Hope I got that all right...I take no responsibility for any foolish attempt to make this stuff, it can be hazardous.

Using the solution to rust blue a gun is another whole process that involves swabbing the solution on very well cleaned metal, rusting it in a steam box, boiling the gun/part and carding off the rust, repeating several times until the desired depth of blue is achieved. I'll let someone else do the honors of writing that up.