Chemical Strawing acid
 

A thread titled "more on strawing" contained a recipe for a chemical strawing solution that required Selenic acid. Can anyone tell me where to obtain Selenic acid in small quantities suitable for home strawing?

If you are strawing Luger parts you need nothing more than heat.

The color is a heat temper, you should not need chemicals.

a recipe for a chemical strawing solution that required Selenic acid. Sounds crazy. Maybe they used the acid to clean the part before strawing? I always use alcohol to final clean before firing up the plumbers torch.
Re read that thread or tell us where it is (link) maybe all will be revealed...

It's really not as crazy as it sounds, like I mentioned in the other thread, selenic acid is one of the components in cold blue. I haven't tried this, but I have seen an engraved pistol where the engraver used diluted cold blue to make the engraving look like gold. I have also read a description for how to simulate case hardening by dabbing cold blue and water on the parts, this will supposedly produce an mottled pattern in different colors. I wouldn't be surprised if the selenic acid actually can produce something like a straw color, but as already said: Heating is much easier. It doesn't involve any hard-to-get chemicals at all, just a good cleaning and some judicious work with a propane torch.

Still a Rube Goldberg way to go about over complicating a simple and correct process! Nasty chemicals..clean pure fire..YEAH!

That's a good way to describe it! :D

The link to the strawing formula is: http://forum.lugerforum.com/showthread.php?t=20598

I am interested in trying the chemical strawing on a 1916 DWM shooter, matching numbers but heavily polished and reblued, including the originally strawed parts. I think a surface chemical treatment reduces the risk of harming these old parts, especially the ejector, with heating by a novice. Also, I believe the chemical coloring is more durable.

No on both. If you heat it to the correct color, you have heated to the same temperature the factory used. In other words: The temper won't be affected. The chemical bluing will be of the same quality as a very thin cold blue, ie. not very durable at all.

If you heat it to the correct color, you have heated to the same temperature the factory used. In other words: The temper won't be affected.

The temps required for straw are very low actually..550 or so. Can be done in a toaster oven. Did I mention chemicals are nasty? Don't go to the dark side! See the LIGHT!

Hey Guys, In the conversation it sounds like straw colors are applied for decorative purposes. I thought the colors were a by-product of tempering a hard piece of steel, such as a spring. Molten salts (potassium nitrate) are still used in spring making instead of an oven.

John

John,

You are correct: The color is not there for cosmetic reasons, it's a result of the heat treatment. Looks pretty darn good though.

BTW: Haven't heard from you in a while... Got anything exciting going on in the shop?

Yeah, those heat colors are pretty: peacock blue on a polished gun is real eye candy.
A lot of same "same ol, same ol' " projects over the winter, but there is a C96 carbine on the drawing board that should be challenging. I'll email ya.
John

Originally, case colors were produced by heating with bones...animal NOT human. Cyanide, a more recent approach, gives a much more garish coloring, rather than the soft, pleasing semi-muted colors of old Colts, Winchesters, etc.

This was a topic in 2008 http://luger.gunboards.com/showthrea...sh-Restoration Eric