Possible to "Mimic" Color Case Hardening?

GunXpatriot · June 30, 2013, 10:02 PM

So I'm looking to restore an old J. Stevens Little Scout Model 14-1/2. I'll be re-bluing the barrel, which is completely stripped of all bluing. I'll also be completely refinishing the stock, which is in fair shape. Now the reason I'm doing all this, is because I more or less got screwed when i bought the thing. I figure I'll turn it into a beautiful wall-hanger and I'll get a little experience performing these tasks.

Now initially, I didn't know exactly what had been applied to the receiver, as it was completely stripped of all color. I assumed it was also blued, but after a brief Google image search, I've found it was actually color case hardened. Watching Larry Potterfield's video, I think it's a little out of my reach.

So, what I'm looking for is a way to "mimic" color case hardening. Does anyone know how I would go about doing this? I'm sure it's possible somehow. Would this be a common thing to try and do?

Also, The only other thing I really worry about is the crown. It has some rust on it and is all chewed up. Actually, the reason I got screwed with this rifle... I took a few guns to a gunsmith yesterday. Another man actually brought this same rifle in to have him take a look at, make sure everything is on the up-and-up. Although his rifle is in much better shape than mine, it turns out it was showing heavy wear on the chamber, with obvious over-pressure. The gunsmith said that with a lot of use, this was not uncommon at the time, mostly because steel was not up to our modern standards, so this is much more rare on guns made the past several decades, but does rarely happen.

Now mine is a different story. Looking inside the chamber, it looks like there are literally 2x 2mm deep gouges in the bottom of the chamber. The right side of the chamber also looks all scratched and chewed up. How that even happens, I have no idea. He'd been jokingly saying that he lets his brother test fire all the guns so he doesn't have to. He said he probably wouldn't even want his brother firing this one. Would it blow up? Maybe not, but there would be over-pressure, as well as the fact that the casing would probably expand into those "gouges", which would make them extremely difficult to remove. So forget firing the thing. :P

So, instead of wasting the other guy's time and money, he decided he wouldn't take on the project, as fixing this would cost more money than the rifle is worth, even in it's great condition (besides the chamber obviously). So, he'll make it a wall-hanger. Now mine, on the other hand, looks almost like complete crap. He said that I should try working on it myself. Since these tasks didn't require machining, it would be good practice. Sounds cool.

So where would you guys suggest I start with this project? Of course my main concern is the color case hardened look, but where should I start? Blue first? Re-finish stock first? finish receiver first? Thanks a lot guys.

Dixie Gunsmithing · June 30, 2013, 11:41 PM

Actually, I sent in the solution to this years ago, to Brownell's, and it is in Gunsmith Kinks 3. You can do it with cold blue, or the kind Brownell's has, as I accidentally stumbled upon it while cold bluing a part. What you do, is completely wet the part with isopropyl alcohol, making it puddle on the steel, and then, using a steel punch or screwdriver, you dip it in the cold blue, then onto the part within the puddle of alcohol. Something between the drop of cold blue, and the alcohol, makes it mimic case hardened color, and you use the punch to sort of make the patterns by moving it around. However, you should apply some clear polyurethane over it, once done. Take a look at Brownell's Gunsmith Kinks 3 for further details.

James K · July 1, 2013, 10:12 PM

The color of case hardening (but not the hardness, unless it is already there) can be easily mimicked with cold blue, simply by daubing it on. But another way is to use a propane torch and spot touch the metal with heat, just enough to leave a color but not enough to affect any hardening that is in the part. The part must be highly polished for the coloring to work. Different colors, ranging from blue to yellow to red can produced by using different temperatures. The color is not very durable, but then neither is true case coloring; manufacturers use a shellac or transparent varnish on the part to extend the life of the color.

Note: Because of the possibility of using too much heat, the above coloring should be used only when strength of the part is not a major factor. It is OK, to color the receiver of an old .22 single shot, but maybe not OK to heat color the receiver of a .300 Win Mag.

Jim

dahermit · July 3, 2013, 12:44 PM

Quote:

another way is to use a propane torch and spot touch the metal with heat, just enough to leave a color but not enough to affect any hardening that is in the part.

It would make me uneasy to apply heat to the receiver of any gun because the steel begins to loose hardness at temperature a lot lower than people think (see below) However, in the case of the original poster, it seems he just wants a somewhat attractive wall hanger. Nevertheless, it may be wise to render the gun permanently disabled to assure some future attempt to fire it. Personally, I would not disable a gun unless I was sure that the gun could never be fixed and become a shooter again and this one, unless I missed something, could be re-barreled and brought back to life. Seems to me that re-barreling, re-finishing and ending up with a shooter would bring more satisfaction that putting time and effort into a dedicated (permanently), wall-hanger.

Heat colors (Fahrenheit) of 0.95 plain carbon steel, from Machining Fundamentals, The Goodheart-Willcox Co., Inc., 1973, : Lt. Straw = 380 degrees, Straw = 420 degrees, Dark Straw = 460 degrees, Purple = 500 degrees, Purple-Blue = 540 degrees, Dark-Grey = 580 degrees.
From: http://en.wikipedia.org/wiki/Heat_treating
"...Tempering consists of heating steel below the lower critical temperature, (often from 400 to 1105 ˚F or 205 to 595 ˚C, depending on the desired results..."

Dixie Gunsmithing · July 3, 2013, 06:19 PM

There are several things you have to look at before adding heat to any steel. First, if it was quenched and tempered, how high was it heated to originally, to a blue for spring, or in the brown or yellow for extremely hard? If it were drawn for a spring, then you can reheat the metal to a yellow or brown and not hurt it, as long as you don't get it to blue and past, and that is because it has already been heated to those points beforehand.

However, in case hardening, there was a specific reason for this. They used a cheaper and softer low carbon steel to make the part, that is not hardenable, and they used case hardening to give the part a tough skin. The inside of a case hardened part is as soft as the steel was when it was machined. The outside has had carbon added to it, by the case hardening process. Here, the part is heated up extremely hot, for an alloted time, while packed in a source of carbon, generally in bone charcoal in our case, and then quenched right out of the oven. If not done correctly, though, a part can warp, and ruin the geometry.

If you flame color a steel, and it is a low carbon steel, or a hardenable steel, it can set up stresses within the steel, especially steel with enough carbon, and cause it to crack under working stress. It acts like the HAZ (heat affected zone) in welding, where a joint can crack on either side of the weld, over the heat generating a stress. The only way to stop it is to normalize it in an oven. I'm not one to teach that flame coloring is okay, and I think it should never be done on a large part like a frame or barrel. Screw heads are okay in some situations.

James K · July 4, 2013, 01:44 PM

Good information, and my response should have taken that into account.

One point, though, is that case hardening was not used to harden cheap or low quality steel, it was used to surface harden iron. In the days before and for a good while after the Civil War era, most gun frames and larger parts were not made of steel but of wrought iron, which could not be hardened. The hardening was primarily to prevent wear from the working of the internal parts, not to prevent wear from outside sources. The color was a by-product and not necessary to achieve hardness - it was cosmetic.

After steel was widely adopted in the gun industry, surface hardening was still used, but color case hardening was reduced or eliminated except where it was retained (as by Colt) for cosmetic reasons.

Jim

Dixie Gunsmithing · July 11, 2013, 12:42 PM

It took a while, but as I had the need to get out Gunsmith Kinks III, to read something else, I looked up my old contribution on this, and since I am the actual author, I thought I would share it with you. I did add what Bob tacked onto the end. (I'm getting old, as I took a peek at the publication date, and this was sent in around 8-9 years before it!)

Quote, page 155:

"S&W-type case hardened hammer/trigger colors

"Here's how to return case color to Smith & Wesson hammers and triggers. First, polish bright with a loose 240 wheel. Then, take a swab of Birchwood Casey's Gun Cleaner-Degreaser, and thoroughly wet the part with it. Without wiping it off, and with it still wet, take a pin punch and dip it into some of your Dicropan T-4, and with a drop on the end of your punch, put it on the part that is wet with the Cleaner-Degreaser. Wait a few seconds until the mottled color is about right, then wipe off with a clean rag. Then, oil. I'll bet you can't tell it apart from the factory case color! Really looks good. (Comment from Bob B.: - I tried this, and it truly works, not only on S&W, but on other pieces of steel. However, I ended up doing it beside a water faucet with the water running, and the minute I got the color I wanted, I dunked the part under the faucet of running water, and rinsed thoroughly, without touching. I patted it dry very carefully and let set until the next day, and then used a very mild mineral oil. Darned if it doesn't look beautiful! This may not be very durable, so would suggest spraying with a dull lacquer before oiling to add to its wear life.) - Matney's Gunshop, Elkhorn City, Kentucky"

June 30, 2013, 10:02 PM	#1
GunXpatriot Senior Member Join Date: November 28, 2011 Location: New York Posts: 393	Possible to "Mimic" Color Case Hardening? So I'm looking to restore an old J. Stevens Little Scout Model 14-1/2. I'll be re-bluing the barrel, which is completely stripped of all bluing. I'll also be completely refinishing the stock, which is in fair shape. Now the reason I'm doing all this, is because I more or less got screwed when i bought the thing. I figure I'll turn it into a beautiful wall-hanger and I'll get a little experience performing these tasks. Now initially, I didn't know exactly what had been applied to the receiver, as it was completely stripped of all color. I assumed it was also blued, but after a brief Google image search, I've found it was actually color case hardened. Watching Larry Potterfield's video, I think it's a little out of my reach. So, what I'm looking for is a way to "mimic" color case hardening. Does anyone know how I would go about doing this? I'm sure it's possible somehow. Would this be a common thing to try and do? Also, The only other thing I really worry about is the crown. It has some rust on it and is all chewed up. Actually, the reason I got screwed with this rifle... I took a few guns to a gunsmith yesterday. Another man actually brought this same rifle in to have him take a look at, make sure everything is on the up-and-up. Although his rifle is in much better shape than mine, it turns out it was showing heavy wear on the chamber, with obvious over-pressure. The gunsmith said that with a lot of use, this was not uncommon at the time, mostly because steel was not up to our modern standards, so this is much more rare on guns made the past several decades, but does rarely happen. Now mine is a different story. Looking inside the chamber, it looks like there are literally 2x 2mm deep gouges in the bottom of the chamber. The right side of the chamber also looks all scratched and chewed up. How that even happens, I have no idea. He'd been jokingly saying that he lets his brother test fire all the guns so he doesn't have to. He said he probably wouldn't even want his brother firing this one. Would it blow up? Maybe not, but there would be over-pressure, as well as the fact that the casing would probably expand into those "gouges", which would make them extremely difficult to remove. So forget firing the thing. :P So, instead of wasting the other guy's time and money, he decided he wouldn't take on the project, as fixing this would cost more money than the rifle is worth, even in it's great condition (besides the chamber obviously). So, he'll make it a wall-hanger. Now mine, on the other hand, looks almost like complete crap. He said that I should try working on it myself. Since these tasks didn't require machining, it would be good practice. Sounds cool. So where would you guys suggest I start with this project? Of course my main concern is the color case hardened look, but where should I start? Blue first? Re-finish stock first? finish receiver first? Thanks a lot guys. Last edited by GunXpatriot; June 30, 2013 at 10:13 PM.

June 30, 2013, 11:41 PM	#2
Dixie Gunsmithing Moderator Emeritus Join Date: April 27, 2013 Location: Ohio Posts: 1,923	Actually, I sent in the solution to this years ago, to Brownell's, and it is in Gunsmith Kinks 3. You can do it with cold blue, or the kind Brownell's has, as I accidentally stumbled upon it while cold bluing a part. What you do, is completely wet the part with isopropyl alcohol, making it puddle on the steel, and then, using a steel punch or screwdriver, you dip it in the cold blue, then onto the part within the puddle of alcohol. Something between the drop of cold blue, and the alcohol, makes it mimic case hardened color, and you use the punch to sort of make the patterns by moving it around. However, you should apply some clear polyurethane over it, once done. Take a look at Brownell's Gunsmith Kinks 3 for further details.

July 1, 2013, 10:12 PM	#3
James K Member In Memoriam Join Date: March 17, 1999 Posts: 24,383	The color of case hardening (but not the hardness, unless it is already there) can be easily mimicked with cold blue, simply by daubing it on. But another way is to use a propane torch and spot touch the metal with heat, just enough to leave a color but not enough to affect any hardening that is in the part. The part must be highly polished for the coloring to work. Different colors, ranging from blue to yellow to red can produced by using different temperatures. The color is not very durable, but then neither is true case coloring; manufacturers use a shellac or transparent varnish on the part to extend the life of the color. Note: Because of the possibility of using too much heat, the above coloring should be used only when strength of the part is not a major factor. It is OK, to color the receiver of an old .22 single shot, but maybe not OK to heat color the receiver of a .300 Win Mag. Jim

July 3, 2013, 06:19 PM	#5
Dixie Gunsmithing Moderator Emeritus Join Date: April 27, 2013 Location: Ohio Posts: 1,923	There are several things you have to look at before adding heat to any steel. First, if it was quenched and tempered, how high was it heated to originally, to a blue for spring, or in the brown or yellow for extremely hard? If it were drawn for a spring, then you can reheat the metal to a yellow or brown and not hurt it, as long as you don't get it to blue and past, and that is because it has already been heated to those points beforehand. However, in case hardening, there was a specific reason for this. They used a cheaper and softer low carbon steel to make the part, that is not hardenable, and they used case hardening to give the part a tough skin. The inside of a case hardened part is as soft as the steel was when it was machined. The outside has had carbon added to it, by the case hardening process. Here, the part is heated up extremely hot, for an alloted time, while packed in a source of carbon, generally in bone charcoal in our case, and then quenched right out of the oven. If not done correctly, though, a part can warp, and ruin the geometry. If you flame color a steel, and it is a low carbon steel, or a hardenable steel, it can set up stresses within the steel, especially steel with enough carbon, and cause it to crack under working stress. It acts like the HAZ (heat affected zone) in welding, where a joint can crack on either side of the weld, over the heat generating a stress. The only way to stop it is to normalize it in an oven. I'm not one to teach that flame coloring is okay, and I think it should never be done on a large part like a frame or barrel. Screw heads are okay in some situations.

July 4, 2013, 01:44 PM	#6
James K Member In Memoriam Join Date: March 17, 1999 Posts: 24,383	Good information, and my response should have taken that into account. One point, though, is that case hardening was not used to harden cheap or low quality steel, it was used to surface harden iron. In the days before and for a good while after the Civil War era, most gun frames and larger parts were not made of steel but of wrought iron, which could not be hardened. The hardening was primarily to prevent wear from the working of the internal parts, not to prevent wear from outside sources. The color was a by-product and not necessary to achieve hardness - it was cosmetic. After steel was widely adopted in the gun industry, surface hardening was still used, but color case hardening was reduced or eliminated except where it was retained (as by Colt) for cosmetic reasons. Jim

July 11, 2013, 12:42 PM	#7
Dixie Gunsmithing Moderator Emeritus Join Date: April 27, 2013 Location: Ohio Posts: 1,923	It took a while, but as I had the need to get out Gunsmith Kinks III, to read something else, I looked up my old contribution on this, and since I am the actual author, I thought I would share it with you. I did add what Bob tacked onto the end. (I'm getting old, as I took a peek at the publication date, and this was sent in around 8-9 years before it!) Quote, page 155: "S&W-type case hardened hammer/trigger colors "Here's how to return case color to Smith & Wesson hammers and triggers. First, polish bright with a loose 240 wheel. Then, take a swab of Birchwood Casey's Gun Cleaner-Degreaser, and thoroughly wet the part with it. Without wiping it off, and with it still wet, take a pin punch and dip it into some of your Dicropan T-4, and with a drop on the end of your punch, put it on the part that is wet with the Cleaner-Degreaser. Wait a few seconds until the mottled color is about right, then wipe off with a clean rag. Then, oil. I'll bet you can't tell it apart from the factory case color! Really looks good. (Comment from Bob B.: - I tried this, and it truly works, not only on S&W, but on other pieces of steel. However, I ended up doing it beside a water faucet with the water running, and the minute I got the color I wanted, I dunked the part under the faucet of running water, and rinsed thoroughly, without touching. I patted it dry very carefully and let set until the next day, and then used a very mild mineral oil. Darned if it doesn't look beautiful! This may not be very durable, so would suggest spraying with a dull lacquer before oiling to add to its wear life.) - Matney's Gunshop, Elkhorn City, Kentucky"