Fire Blued Lock

[jonboyb]

Just picked up a new toy and I knew it had a fire blued lock.....but this thing is otherworldly compared to anything I've ever seen. These pictures don't do it justice but this thing is BLUE and unbelievably consistent color across the whole plate, but definitely some rainbow to the **** and pan. The rear of the plate of course wasnt as well polished and definitely has more color variation. I've fire blued parts before, but how in the world do you get this kind of consistency? Mirror polished first, very consistent forge temps, etc? This is an old small Siler built by Herman Stone from Locks&Stuff years ago, maybe he did it? Anyways, it's an acquired taste but impressive none the less. Definitely more skill, patience, and knowledge than me for sure

 

[NorthFork]

That dear sir is stunning, a work of art. Beautiful!

 

[jonboyb]

I assure you my attempts look NOTHING like this

 

[dave_person]

Hi,
That is simply temper blued and overly polished. Look at the screw holes how they are dished out. A polishing wheel was used excessively and it shows.

dave

 

[oldwood]

I would say , no offence meant , but Dave is right about the over polishing. Corners should be square looking , screw holes should be square sided. As far as the procedure on how to accomplish a fire blue , there are a couple ways that work. The only fire blued lock I have ever seen was done by **** Getz , back in the 1980's. He said he simply put the polished parts , w/o the springs and hardened parts , into a 400 deg. oven until it looked right...........oldwood

 

[ohio ramrod]

I don't have any pictures , but I have had good results getting "rainbow" blued parts by heating with a propane torch and spraying with WD40.(not for springs)

 

[andy52]

Has the look of the old Colt royal blue which was a fire-bluing process.

 

[fjrdoc]

I would imagine that lock plate was done using a nitre salt process. I think that would be the only way to get a consistent blue color over a large part like that. Nitre salts are melted and if the temp is maintained around 600-650 degress it's kept in solution until it reaches the color that you want.

 

[dave_person]

Hi,
Using nitre salts is not necessary to obtain an even blue.

You just need to heat the part evenly either in an oven for some time or it can also be done by placing the part on a heavy steel plate and heating from below. The oven is best.
dave

 

[GREENSWLDE]

If the parts are covered in a pile of Charcoal ash all the air will be excluded. Makes for a much more even blue. Marble wash stand top is ideal for the table, heated from under with a gas ring. Further you will need a dish of dry powdered lime,a bunch of Tow and Asbestos Fingers.Take out often.When colour starts to show Clean all over hard with lime on a bunch of Tow. REPEAT until you have a Blue so deep you can't see the bottom. Start with a Mirror finish and you will end up with a finish to compete with the Best London Charcoal Blue. I'm only an old amature but was taught by the best in the old B'ham trade {Who did a lot of the London Work}, by a chap called Billy W------- in the 50's thru 60's. Does any one remember him. His firm still works in B'rum under the Staint Ledger header.. Very OLD DOG..

 

[Rifleman1776]

Dave, I'm running out of "Wows!" when looking at yer stuff. Did you know John Braxton? He made Jaegers and had a great fire blueing on his locks.

 

[fjrdoc]

Dave, am I right about the temp range running around 600-650. I've done fire bluing on smaller parts but haven't had success getting a consistent blue on larger parts. I don't believe that my oven would get up to the proper temp needed.

 

[dave_person]

Hi fjrdoc,
A polished piece of steel should turn indigo blue at about 590 degrees F. The blue will deepen somewhat the longer you hold the temperature there. In charcoal bluing the temp is usually higher. I had good results charcoal bluing first at 900 degrees and then again at 800 degrees F heat soaking for 3 hours, then letting cool and rubbing the parts with rottenstone and linseed oil. Degreasing, and then doing a second heating and rubbing cycle. However, I learned from one of the best barrel and hardware finishers in the world that he preferred much lower heat, around 650-700 degrees but still soaking the part for several hours at least.

dave

 

[fjrdoc]

Thanks for your info Dave. I'm always anxious to learn anything that I can in regards tom metal finishing.

 

[dave_person]

Hi,
Thank you Frank. I get there because I dive in and try things and learn. I am afraid of nothing and I am not intimidated by any task or skill. I simply figure out how it was done, consult with folks who are knowledgeable and then just do it. I accept failure and learn from it. But learning is the key. Perhaps, more importantly, I work at it. I do my home work, I practice, and I put in the hours.

dave

 

[GREENSWLDE]

Hi,
Thank you Frank. I get there because I dive in and try things and learn. I am afraid of nothing and I am not intimidated by any task or skill. I simply figure out how it was done, consult with folks who are knowledgeable and then just do it. I accept failure and learn from it. But learning is the key. Perhaps, more importantly, I work at it. I do my home work, I practice, and I put in the hours.

dave

Your temp' are rather high for members this side as we were forced into Code Napoelian by Brussels.
Press the conversion button on your i-phone calculatoror or find what used to be called a slide rule. It will be usefull when the internet finally Blows-Up.. O.D.

 

[dave_person]

Hi Greenswlde,
Just subtract 32 and multiple the remainder by 5/9. Easy and it is not even based on 10.

dave

 

[Ozark Mtn Muzzleloader]

I would imagine that lock plate was done using a nitre salt process. I think that would be the only way to get a consistent blue color over a large part like that. Nitre salts are melted and if the temp is maintained around 600-650 degress it's kept in solution until it reaches the color that you want.

I’d bet you are absolutely correct.

 

[dave_person]

I’d bet you are absolutely correct.

Hi MM,
See any unevenness here?

No nitre salts used, just even heat, long heat soak, and repeated cycles of heating and rubbing back with lime or rottenstone.

dave

 

[GREENSWLDE]

Nice Blue David. Do you use a pile of charcoal ash on a hot plate. I,like you use Dry Lime powder.. O.D.