Strawed parts

[BILL]

What kind of strawing process was used by DWM on the early models (1900-1906)? I have been looking at some parts from a 1906 commercial and the areas of the strawed parts that don't get exposed (i.e. inside the back of the trigger) are a very distinct brownish color. Comparing this to a WWI trigger, same location, totally different color. Was there a chemical process involved or just a heat treatment? I also noticed some difference from both of these when I look at a 1923 commercial. I see several distinct colors which leads me to surmise that there must have been different processes other than just the temperature of heat treating. Any documented strawing procedures?

There is a basic discription of the process used in "Luger Variations" by H.E.Jones.


"After being polished and cleaned with alcohol, the parts were inserted into a preheated oven (440 deg F) for 15 minutes, removed, air cooled and oiled"


Perhaps the variations that you see, are due to both different polishing techniques, or temperatures or both.


FGR

Would it be possible that exposure to UV light from the sun and other sources over the years would cause the variations? TomN

[Thor]

Ralph Shattuck has told me personally that strawing light tends to fade strawing as abrasion through handling will remove it also. The result is a tarnish silver color of the aged white steel. Thor

[BILL]

I knew it looked like something I have seen somewhere before and it does look like tarnished silver. I don't know how to describe the color of tarnished silver but that is very close to what it looks like. This is not where any light or fingertips could have ever been, though. Thanks. What color *is* tarnished silver, anyway?

Straw color is achieved by heating the metal. Have been doing this for about 30 years. Straw starts at about 440 more heat makes it darker. Keep heating--gets purple--then bright blue--more heat gets gray then bright. Brightness of straw gets better the more the steel is polished. Note that front and sides of triggers still show some file or mill marks but are polished fairly bright otherwise. Back of trigger was not polished so color is darker and less pronounced. Colors and degree of polish vary from 1900 to 1937. Straw wears off with use more than blue.

[Rick K]

Tarnished silver trumpets are dark gray.

[Thor]

Bill Chase never had a tarnished trumpet! Right Rick? But lots of SUPER Cees!! DUWEETTTTTTTT!! PoorThor

[Rick K]

You got that right man!

[Rick K]

What's this "poor Thor" stuff? Get your axe out, oil up the valves and get your lip back! I'll bet you've come closer to a super ceee than I have!

[Jesse]

Hey Art,


Thanks for the info!!!! I have been up all night strawing old gun parts

[Big Norm]

Art,


I have a lot of questions about strawing. I read about it in Walthers 'The Luger Book'and have been talking it up for a few years. I had some guys tell me that they have used a process that they called dunking in molten lead. Have you heard about that process?


I have heard that some guys have just put the part on a metal strip in a vice and used a torch until they got the proper color and then dunked it in transmission fluid to stop the heating process.


Other guys use an acid to remove the patena and some other guys use wet/dry sandpaper to remove patena. I have thought about the acid process and figured that it would prevent what I call a 'rolling of the wrists' particularly on the locking bolt. The rolling of the wrists causes the amateurish rounding of the edges on parts. In reality this is the removing of too much metal and makes the strawed parts look terrible.


I have thought about it for a while and I figured that any oven just keeps the temerature within a range of say 350 to 450 degrees. When the temperature drops to the lower range the oven heats up to the higher range. So how do you keep the temperature fairly constant at 400 degrees? Do you dip the strawed parts in something to stop the ambient temperature from over coloring the strawed parts.


I have some mint lugers and I have noticed that the strawed parts have a light varnish like coating on them. Did the Germans dunk the parts into some coolant after strawing to stop the cooking process? is this light varnish coating and result of the hot metal over heating the coolant and attaching itself to the metal?


My thoughts on the first part of this thread is that the color differences in hidden areas of the strawed parts might be the result of these parts being hung on something while being cooked. This was mass production. What ever they were hung on could have a different temperature and therefore would give a different color.

Big Norm

You know, I think it's time we add the strawing process and variations to the frequent question list...


Ted is really one of the resident experts in the field, but he is understandably hesitant to explain his procedure.


I suspect the varnish look that we sometimes see on the parts is simply old oxidized oil.


I believe that I read somewhere that the original parts were air cooled and dunked into sperm oil, the modern equivalent is transmission oil.


Oven heating can work. I have heard of people putting a pan of (clean) sand or shot into an oven with a thermometer to measure the temp. When the is correct for their application, the cleaned and buffed part is "cooked" on/in the shot until the color is reached. One old text I have suggests a stove top heavy iron plate. And Brownelles sells a product, a salt bath, that is specifically for strawing and bluing small parts (along with instructions) called Nitre-Blue. It can be used on a stove top or hot plate.


Obviously the more control you have over the bath temperature, the higher the repeatability will be, so I suspect that it would be very hard to get consistent results with a torch.


But while strawing of a metal is temperature dependent, it is also dependent upon the metal, it's alloys, carbon content, hardness, previous work history, and probably a few dozen other parameters that I am unaware of, so practice seems essential.


There were some excellent posts a while back on strawing and different processes.


hope this helps some...

FGR

[Johnny Peppers]

While not the same thing, the old time shotgun makers lacquered the casehardening on their shotguns to bring out the brilliant colors of the casehardening. As there is no evidence to indicate that strawing was used for any purpose other than a beautiful contrasting color to the blue of the Luger, the parts could have been originally lacquered to enhance the straw color. As on the shotguns the lacquer would not have lasted long with use.

Art has hit your nail on the head. I do similar work. Failure to keep oil or grease on the metal surfaces will cause "fading" over time. Due to simple oxidation.......oxygen in the air. That is why many Mauser lugers may appear somewhat pale, when they actually started out quite dark.

[ViggoG]

Johnny Peppers and John Larr

I think that you both have it right on the nose.

It would be very easy to dip parts in a very thin lacquer

and shake dry it drys so fast that way and wouls protect

the straw color for some time, Also Its well to note that

Museums use Pure Carnuba Wax to protect many of their best

Antiquities .

I for one preserve my guns with pure Simonize wax ( with no

cleaners or self polishing addatives ). Works well for me

even on rainy days the water just rolls off and it works on

the Wood and plastic stocks as well .

2 cts +++


ViggoG

The American Gunsmithing Institute (AGI) has a very informative step-by-step vidio course on Rust & Nitre Blueing and including 'Strawing Luger Parts'. It is three hours long and the reference number is course #310. 1-800-797-0867.This will help anyone who is interested in these processes.Have fun, Gene Shuey

Gene,


I looks like this video is ~$60.00... have you seen it?

FGR