There are so many variables involved including the person doing the bluing.
The type of steel being blued has a lot to say with how well the completed finish stands up to handling and wear.
The older & softer steel bbls and parts blue much better as far as durability goes.
Some modern alloys seem to resist most classic rustblues but blue nicely w/a hot salt process.
Not that you can't get them to rust, then boil & change to blue and card them, ect. They just don't stand up as well as one would expect. They wear very quickly at the edges and high spots when handled.
Not what you'd expect from rust blue properly done.
Sometimes the cold rust process has to be abandon and the quick rust process used. I've used a combination of both on some bbls to get what I want.
Each piece can be so different from the next.
When removing a blued finish by filing or abrasives,,the hot blue will file and polish off with no noticable loading of the file or abrasive paper.
A rust blue finish will load a file right up with a dense red powder (rust) as you try and draw file the tubes out.
It's easier and less time consuming to remove the rust blue with a chemical first,,then do the draw file work.
Even the chemical like common Naval Jelly will take quite few minutes to start to work through a decent but old rust blue finish.
Placed onto a hot blue finish, the blue will begin disappearing in a matter of a few seconds as you brush it on.
In the end I guess that little exersize proves little other than it takes less effort to cut through the hot blue than the rust blue.
Neither is bullet proof and both will eventually wear. They both need attention to keep the surface from rusting.
As with most everything in this business,,there is never only one way to do things to get the desired results.
..and it's the results that count.
