Seeking Assistance for Roy Dunlap's 1950 Gunsmithing Recipe

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The discussion revolves around the formulation and application of 'Old American Rust Blue' for gunsmithing, as detailed in Roy Dunlap's 1950 book. The original formula includes nitric and hydrochloric acids, but lacks specific concentration details. Participants suggest using concentrated nitric acid (around 60%) and hydrochloric acid (28% or 31%) for effective results. They discuss safety precautions, emphasizing the need for proper ventilation due to the hazardous nature of the acids. A specific blueing formula is shared, along with alternative methods that are safer and more cost-effective. There is also mention of a transition from hot blue processes to rust blue processes, with recommendations for further reading, including James Howe's "The Modern Gunsmith." Overall, the conversation highlights the complexities of acid concentrations and safety in the context of firearms restoration.
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I'm new here and not a Chemist. Last learnin' on subject was in HS. Maybe someone can assist. Thanks

I have researched Roy Dunlap's 1950 Gunsmithing book and found a solution called 'Old American Rust Blue', and I am contemplating mixing up a batch. Formula calls for Nitric and Hydrochloric acids, but do not mention concentration. Nitric Acid is available thru this source in 70-60-and 40%. Hydrochloric Acid is 28%. Is anyone aware of what concentrations would have been referred to in the old books?
Thanks again
 
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If you're looking for good yields you'd probably have to use the concentrated stuff. Don't go crazy or anything though, 60% HNO3 should be good. I'm sure the HCl isn't of much importance here so 28% should be fine, although most common HCl (muriatic acid) goes as 31%. I've never heard of this stuff before, care to mention a few details?

Edit: Should also add that if you needed a higher concentration (ie. something didn't work right) you can always concentrate it by boiling some water off. Might not work with the HNO3 though, I think it forms an azeotrope (lower boiling mixture) at 68% or something. And if you plan on doing this, DO IT OUTSIDE, or in a well ventilated area, especially if you do it with the HCl. THat stuff is wretchedly wretched when it comes to stink.
 
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thundervck, thanks for the heads up.

Blueing formula is:
Nitric Acid- 4oz.
Hydrochloric Acid- 3oz.
Iron(clean nails) 1/2#
Water(distilled) 1qt.

Acids mixed together in crock pot (outside) and nails added. After nails dissolved, ad water and put into colored/glass stoppered bottles.
 
Dave Wolfe's version of the recipe cuts the acids at one volume each to ten volumes of water. This is a restoration project? There are much cheaper, safer, cleaner, easier methods of bluing these days.

http://www.real-guns.com/Commentary/comar51.htm

http://www.andyscustomshop.com/winchester_services/index.php

http://www.finishing.com/0800-0999/982.html

--- and, it really does look cheaper to have it done.
 
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Hmmm...
And what does this all do? Sounds interesting.

I'm not really sure if what I've told you is ideal. You should probably do some more searching on the subject to find people who have actually done this and see what they have to say...
 
Oh okay. It's to make guns look nice or something? I thought you were making an explosive.
 
bystander, you hit it on the head:
http://www.real-guns.com/Commentary/comar51.htm

I have been using Plinkingtons American Rust Blue and it works great/ but expensive ar $30.00 per 4oz. A gunsmith friend is interested in switching over from the hot blue process to the rust blue process. Doing commercial work with the 'pricy'4oz. bottles just may be made practical with one of the two fromulad in Dunlaps book.

The one noted, OR (commonly known as Neidner's formula):
Nitric Acid- 2 1/2oz.
Hydrochloric Acid- 2oz.
Nails- 1oz.
Distilled Water 30oz.

I am sure it is one of these. I would be more inclined to think the first due to more iron residue in the commercial product I have been using. By the way, done as stated it does a DYNAMITE job!
 
If you're going "commercial," it might pay to get your hands on The Modern Gunsmith, James Howe (see it off and on at gunshows --- must be 50-60 years out of print). Failing that, have the local library copy vol. II pp. 200-230 from an interlibrary loan --- just skimmed it again, and it's about as good a description of process and pitfalls as I've seen --- probably want the glossary from the back of vol. II, as well, for his definitions of terms (give you some idea of what the "alchemists" meant when they said "nitric acid" and "hydrochloric acid" as far as suppliers, concentrations, acceptable trace metals, ta-da, ta-da, ta-da). It's conceivable you could get it through Border's or one of the on-line out-of-print specialists.

Sounds like fun.
 
Thanks Bystander, I'll look for it...

thundervck,
"GAWD, NO!" I 'Was' a bomb tech., went to Redstone (class B-2-89), am now retired, and DO NO LONGER MAKE BOMBS ...period!

thanks all...
 
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  • #10
Wingnut,
Send an e-mail to Irvcindy@hotmail.com. Irv has a GREAT cold blue formula that is cheap, and easy to use. He's also a big fan of Donlap.
-Mike
 
  • #11
Rust Blueing Acids

Thanks for the heads-up Michael, 'roger that':smile:
 

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