I decided to give this a try,however had a hard time tracking down the chemical .
A new company took over the DuPont products. Now called AXALTA # 5718S steel and galvanized conversion coating Step B. $32.50 a quart around here
Thanks Dave, I just was wondering if one of the largest companies still in the US had thrown in the towel. Fred Looked it up they sold off the car paint division to overseas company though DuPont still exists. car paint was their largest market. FM
In my First Edition of Machinery's Handbook, on p. 1,219, the formula and procedure is given for producing a "gray color" on steel along with some intermediate colors depending upon how long the process is continued. Some of these chemicals shouldn't be difficult to obtain, and for ferric chloride, one of them, guys who do circuit boards probably have some on hand. If you can't Google the above mentioned text or page, I can write out the whole thing in a future post. It might be cheaper going this way, but I haven't priced out anything. It could be that for the cost of a few chemicals, assuming there's no minimum, you might be able to do a number of batches. Looks like I have another future project to get involved with. I have o personal experience with the process, so I can't otherwise advise. Maybe this new chemical is cheaper & faster?