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Color Hardening Questions
- Thread starter 4575wcf
- Start date
- Replies 26
- Views 4,390
john.k
Diamond
- Joined
- Dec 21, 2012
- Location
- Brisbane Qld Australia
I d be a bit careful of whats actually going on.........most of the gun restorers do a "sub critical" colour.......bright colours ,but any actual hard case is softened by the process..........the beauty of sub critical is that there can be no shrinkage of parts ,which is a big risk with guns with long tangs ,which tend to shrink in actual high temperature colour case ,and no longer fit the wood.
Okay I think I am following here. I am not familiar with "masking" and I am not familiar with "sub critical". I assume the first is a way to protect pre-colored parts to allow the soft ones to color the same, I assume sub critical is to harden at a lower temperature? Sorry, I am a long term machinist but very new to case coloring. Shrinkage would be no issue, I am building the wood and repairing or building nearly everything else as well.
john.k
Diamond
- Joined
- Dec 21, 2012
- Location
- Brisbane Qld Australia
I just saying the restorers use sub critical colouring,because colour is whats wanted,and distortion cant be tolerated......if you want hardness ,then the best modern process is vacuum carburising.....but this leaves an even grey colour ,and somewhat shiny if the part was originally polished.......Incidentally ,for the hobby builder ,chrome moly steels dont satisfactorily carburize,which is why you dont see a 4110,or 4115 listed.
I did a bit more research. It seems good colors without much hardening can be gotten around 1350 degrees. Very dark colors can be gotten at about 1500 degrees, and no colors at all at 1600 degrees. I think the suggested temperature of about 1450 is going to be the best compromise. I will be using a forge, so some means of controlling temperature must be thought up. For now I am just prepping parts, my first hardening try is still quite a ways off.
eKretz
Diamond; Mod Squad
- Joined
- Mar 27, 2005
- Location
- Northwest Indiana, USA
"Sub-critical" just means they are staying below the critical, or transition, temperature normally used for hardening that steel alloy.
And 4*** series steels don't need to be case hardened, they have plenty of carbon. If you need a hard shell, you'd flame or induction harden those. For a very thin hardened layer you can actually do induction hardening underwater so you get an instant quench as you travel down the part like with flame hardening lathe ways. Not a simple process though...
And 4*** series steels don't need to be case hardened, they have plenty of carbon. If you need a hard shell, you'd flame or induction harden those. For a very thin hardened layer you can actually do induction hardening underwater so you get an instant quench as you travel down the part like with flame hardening lathe ways. Not a simple process though...
partsproduction
Titanium
- Joined
- Aug 22, 2011
- Location
- Oregon coast
I watched a video of Uberti CCH and the parts looked like quenching went in with the dullest visible red. Their colors seem good to me but it seems to me the best effect would be both a hard surface and good color.
pat_j0nes
Aluminum
- Joined
- Sep 9, 2018
- Location
- Colorado, US of A
Are you intending to stock the gun after you have it case colored? Inletting the stock can damage the finish of the metal. You're in and out of the wood a million times, tapping the action with mallets to transfer the inletting black. Not to mention you're shaping the outside of the stock and you'll have files and other abrasives near the metal finish.
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Pat Jones
Firestone CO
Hey All
Thanks for the responses and keeping this thread alive a bit longer. I am building a field grade double on a stripped and rusty LC Smith FWT frame that I bought some months ago. I am finding and using rougher parts, since part of the fun for me is identifying and cleaning up useful goodies in parts lots. My goal is to not use parts that are so nice that they could be used to restore a fine original. They aren't making any more of these guns. I know six times more now about LC Smiths than I did six months ago, but I still have much to learn. I will assemble, troubleshoot, do the woodwork, finish the wood, case color, and rust blue in order. You can find my build on the Shotgun Forum in the High End Specialty Shotgun Forum. I am having a ball, and doing the write up to keep myself on task. So far I haven't attracted any similar builders to bounce plans and ideas off of.
Thanks for the responses and keeping this thread alive a bit longer. I am building a field grade double on a stripped and rusty LC Smith FWT frame that I bought some months ago. I am finding and using rougher parts, since part of the fun for me is identifying and cleaning up useful goodies in parts lots. My goal is to not use parts that are so nice that they could be used to restore a fine original. They aren't making any more of these guns. I know six times more now about LC Smiths than I did six months ago, but I still have much to learn. I will assemble, troubleshoot, do the woodwork, finish the wood, case color, and rust blue in order. You can find my build on the Shotgun Forum in the High End Specialty Shotgun Forum. I am having a ball, and doing the write up to keep myself on task. So far I haven't attracted any similar builders to bounce plans and ideas off of.
john.k
Diamond
- Joined
- Dec 21, 2012
- Location
- Brisbane Qld Australia
Strange things in the gun world.....stuff like high end doubles was gold a few years ago ,milsurps were common as dirt and priced accordingly........now everyone piling into milsurps ,prices have gone insanely stratospheric,and left the "best gun" collectors floundering........even old Winnies and Colts ,the longtime haven of the aged millionaire collector ,seem to have fallen by the wayside ,to some extent...........Strangely (or not) the biggest price jumps are seen in WW2 guns with Swastikas imprinted thereupon.....(Nazi proofs and marks)
MetalCarnage
Stainless
- Joined
- Apr 24, 2011
- Location
- Nebraska
I think a lot of the present interest in the surplus guns with nazi proof marks is the 75th anniversary of the end of WWII. Lot's of old war movies on TV, documentaries, etc.
JMHO
-Ron
muckalee
Cast Iron
- Joined
- Jul 17, 2011
- Location
- Americus, Georgia
Here is a bit about temper color.
Temper color forms when a steel is tempered or cooled in air or a mildly oxidizing atmosphere. The color ranges from straw to blue depending on the thickness of the oxide skin. The temper color versus temperature for carbon steels held at a certain temperature range for ten minutes or less is as follows.
Color Temperature
very faint straw 400*F
faint straw gold 440
straw gold 475
bronze 515
purple 540
blue with purple tinge 640
deep blue-gray 700
300 series Stainless
very light straw 700
light straw 800
straw 900
dark straw 1000
bronze 1100
peacock 1200
blue 1300
light blue 1400
Temper color forms when a steel is tempered or cooled in air or a mildly oxidizing atmosphere. The color ranges from straw to blue depending on the thickness of the oxide skin. The temper color versus temperature for carbon steels held at a certain temperature range for ten minutes or less is as follows.
Color Temperature
very faint straw 400*F
faint straw gold 440
straw gold 475
bronze 515
purple 540
blue with purple tinge 640
deep blue-gray 700
300 series Stainless
very light straw 700
light straw 800
straw 900
dark straw 1000
bronze 1100
peacock 1200
blue 1300
light blue 1400
eKretz
Diamond; Mod Squad
- Joined
- Mar 27, 2005
- Location
- Northwest Indiana, USA
If it was made of stainless maybe. I would much rather use a temperature controller...
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