rust bluing

Can someone describe the rust bluing process and why the Germans used it? Thanks Ed.

[Dok]

article, complete with pictures, in the FAQ which is located in the General Information section of this site.

[RET]

There is a book, Firearm Blueing and Browning by R. H. Angier, that is (or was) available from Amazon.com that covers rust blueing in detail, but the general process is as decribed in the General Information/Frequently Asked Questions, with an additional step: the rusted parts are boiled (usually in plain distilled water), or subjected to live steam (the steam cabinet described is not at boiling temperature, but is warm and damp to promote rust formation) before they are carded. This converts the soft red rust into the harder black oxide.


All of the processes described by Angier pretty much follow the above pattern, but the formulas for the blueing chemicals vary greatly.


Bob

[BILL]

Is there any documentation/speculation as to the actual formula used for the earlier DWM Lugers? I have read the book by Angier and while there are references to certain firearms with relation to formula, there is no mention of DWM. I wonder if there is any actual documenation of their detailed process. I know that Colt held this data to be one of their top secrets. (BTW, years ago I used a browning formula from this book and followed it to the 'T' with excellent results).

[Hugh]

An undocumented authority stated that they were hung on racks under the men's urinal for several days, but I have been unable to get Ted to test this theory!

[BILL]

Well, so much for Colt's top secret formula..all kidding aside, there is a metal finish that Colt used in the early days to get the flame-blue cylinders, so I have read. They sprinkled bone-charcoal onto them, tied them tightly in rawhide and set them into the hot coals of a fire. When the fire died down they poured urine on them and let them cool. It doesn't sound too scientific does it? I wonder how many they had to buff back down and start over? Having said all that..any ideas on how metal was 'japanned'? I have several pistols, none Japanese, that have what is referred to as 'japanned' small parts. Any ideas?

[Hugh]

Bill, somewhere in the deep, dark past I think I reas that "japanned" means "tin plated". But I stand to be corrected.

[BILL]

Nawwwwwwwww..really? I am thinking of that color you see on the hands of old pocket watches, markers found on old scientific gauges, old music box springs..it is a nice dark royal kind of blue. From what I am thinking it has to be a heat treatment of some kind. I think I first encountered it when I took old alarm clocks apart as a child. But..'japanned' and tin plating do ring a bell in my mind. It could be the old 'school's out' bell, who knows?

[Hugh]

The blue you are talking about is the "fire blue", or "Colt Blue", or "S&W Blue" discussed in an earlier thread!

[BILL]

Again, Hugh, you are correct. Having just jumped to a page on 'jappaning' (an old process that used a shellac and pigment to coat metals but in modern times has been done with heat treatment). This is apparently what we in the firearms arena call it fire blued (if you were an old tool collector you would call it 'japanned'). Thanks for the good input.