Seeking Assistance for Roy Dunlap's 1950 Gunsmithing Recipe

  • Thread starter Thread starter wingnut
  • Start date Start date
  • Tags Tags
    Assistance
Click For Summary

Discussion Overview

The discussion revolves around the formulation and application of Roy Dunlap's 1950 Gunsmithing recipe for 'Old American Rust Blue', focusing on the concentrations of nitric and hydrochloric acids required for the process. Participants explore the historical context, practical applications, and alternative methods for bluing firearms.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested
  • Experimental/applied

Main Points Raised

  • One participant seeks clarification on the acid concentrations mentioned in Dunlap's book, noting the availability of nitric acid in various concentrations and hydrochloric acid at 28%.
  • Another participant suggests that for good yields, concentrated nitric acid (around 60%) should be used, while stating that 28% hydrochloric acid is likely sufficient.
  • A specific blueing formula is shared, detailing the amounts of nitric acid, hydrochloric acid, iron, and distilled water needed for the process.
  • Alternative methods for bluing are mentioned, with one participant referencing a version of the recipe that dilutes the acids significantly with water.
  • Concerns about safety and the practicality of using the discussed methods are raised, with suggestions to explore other options that may be safer and more cost-effective.
  • Some participants express curiosity about the purpose of the process, with one mistakenly suggesting it might be for making explosives.
  • A participant shares their experience with a commercial rust blue product and expresses interest in switching to Dunlap's formula for cost-effectiveness.
  • Recommendations for additional resources, such as "The Modern Gunsmith" by James Howe, are provided for further understanding of the process and its nuances.
  • A participant humorously clarifies their background as a former bomb technician, emphasizing they no longer engage in bomb-making activities.
  • Another participant offers a contact for a cold blue formula that is noted to be inexpensive and easy to use.

Areas of Agreement / Disagreement

Participants express a mix of agreement on the general interest in the recipe and its applications, but there are competing views on the ideal concentrations of acids and the safety and practicality of the methods discussed. The discussion remains unresolved regarding the best approach to take.

Contextual Notes

Participants note the historical context of the recipe and the potential variations in acid concentrations, as well as the importance of safety precautions when handling chemicals. There are references to alternative methods and resources that may provide additional insights.

Who May Find This Useful

Individuals interested in gunsmithing, historical firearms restoration, or chemical processes related to metal treatment may find this discussion relevant.

wingnut
Messages
5
Reaction score
0
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
 
Chemistry news on Phys.org
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.
 
Last edited:
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.
 
Last edited by a moderator:
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...
 
Last edited:
  • #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: