Thanks Jeff. What is interesting to me is that I have gun blued things before and the solution typically and very quickly changed the finish to a very dark "gun barrel" color. Your example basically looks natural with no darkening color?? Process? ............
I rarely dip anything in the gun bluing - only if its a large part and then I've had issues getting a consistent look everything.
On things like spindles I'll use a acid brush to work from one end to the other getting the finish dark like heat treated. On large pieces that have been recently stripped or even blasted and or wire brushed I return those to new metal look using steel wool daubed in gun bluing and rubbed (starting from one end) it into the surface to slightly darken (working the bends a little more to brighten them) from one end to the other. If I get a spot that gets to dark (using too much liquid on the steel wool) I can wire brush that area and try again until I'm happy
Used the same technique on the main section of drive line (before the the heat stripe)
In the picture you can see the slightly darkened area (I'm working bottom to top on the lower A arm) in front of the steel wool.
Yes I see the pitting on the arm
Se we do have rust
Now a couple of things I found. Pour a little gun bluing into a small container and refill as needed. Once the fluid comes in contact with the steel wool DON'T pour in back in with the unused liquid - its done. It is a subtle but noticeable change.
Some how, chemically, the fluid reacts with the steel wool, darkening it first, and this reduces the fluids ability to darken the piece your working on as it normally does if dipped, applied with a brush or a rag.
If I'm need to darken a couple of screws or a small piece I drop an oz of the liquid in a small paint cup, Dixie cup or similar cup and slosh the fluid around with the part for about 10 seconds - once the fluid has cover the surface of the piece completely. Remove it, flush and wipe it then treat it with heat and oil for a 2 minute plating process
Without having to dip front or rear springs I'm normally able to do everything I need on a car using only two of the small bottles of the repair fluid. I didn't buy from another company a 32 oz bottle last time since locally its difficult to buy the stuff any more- once the meth heads figured out how to use the stuff in their cooking recipes
Just what has worked for me.