Campfire color case

[JPK]

I would like to share an experiment that came out well. I used bone and wood charcoal and packed the part as normal then placed in the fire. I didn't time it or measure the temperature other then guessing. The water is tap water nothing added. The first photo is all the equipment used.

[d-a]

That looks great will have to try that one weekend when I get a cruicable

d-a

[rich pierce]

Did it get hard?  Niche colors!

[razor62]

That's amazing!!! Please provide any info with regard to the process that you used. Even your best guess as to time in the fire, ratio of bone to charcoal etc. If this is repeatable I would be thrilled! I've been wanting to try this for so long but all of the stories of failed attempts dissuaded me from making an attempt myself. I can't express how exited I am to hear that you've managed to pull it off so simply.
Absolutely gorgeous colors!!!

[Dew]

Wow! That looks good. I would also like any info that you would share. I thought you had to have a forge or an oven to do this.  I don't have a forge but I can make a camp fire. I have a Hawken I'm hoping to start on here before to long. Thanks

[Nordnecker]

Yeah, those colors look great. I tried that one time on an unimportant part. I figured I'd just put the part and some horn and leather in a "tin" can and toss 'em in the woodstove for a while and take it out and drop it in a bucket of water. Unfortunately my "tin" can must have been made of aluminum, because about 10 minutes after I put it it the stove it was not to be found. No matter. The next day, I dug the piece of metal out of the ashes. It was scaled solid black. All my filing and polishing was gone and it was annealed soft as lead.

[JPK]

The part is hard and I'm pleased to share details. The crucible is a steel tube with a 1/8" plate welded on for a bottom and another just sat on top. The mix is 1 to 4 bone to wood charcoal with the part placed in so it's surrounded on all sides by an inch or better and 1 1/2" from bottom. The top layer is an inch with the rest filled with used charcoal to fill the tube completely. Light tapping to settle the pack but not compressed at all. Time was around an hour and a half (W.A.G.) and we cooked chicken on the side. Just before dropping the part in the water I poured the water from one bucket to another and back just to stir it up, I feel this is important to the process.
 Now some guessing on my part based on what I understand about color case hardening. The carbon gasses released during the heating are absorbed into the surface of the iron if it reaches a high enough heat. These mixes of carbon are purer from charcoals and if I were to go threw the extra effort of using leather, horn, peach pits, and other suggestions I've had I would first put them in a container and heat them to make a charcoal out of them.  I would love to hear and see any ones results if you do try them, good or bad. Another tip if you want muted colors yet hardening quench in oil. A sample on 12L14 steel.

[razor62]

Thank You JPK!!!! I'm inspired!!!   

[Acer Saccharum]

Someone posted that longhunters re-cased their frizzens on the trail, maybe using clay crucibles, or a sheet iron container, packed with charcoal.

I assume one would have to 'coal up' leather or bone before use as a pack material.

[oldone]

Very nice Acer, Very nice. XI will be trying it

[D. Taylor Sapergia]

That looks very encouraging.  I know a guy in Chatham NY who tried this a few years ago, and got great results.

[bob in the woods]

I tried this process in my shop's wood stove once and it worked OK [ leather and bone packed container] but have been meaning to try using sugar on an up coming project. I read some where that sugar, being pure carbon, works well in case hardening . Anyone else tried it ?

[Acer Saccharum]

The place I send work to for industrial case hardening uses carbon monoxide gas to fill the furnace. I imagine that's what's happening inside the charcoal packed crucible. When you add leather, bone and peachpits, you are adding other chemicals to the gas inside the crucible. Potassium, calcium, cyanide? I am guessing now, because I ain't no chemist.


Here I yam, dumping parts and charcoal into the bucket. I put a wire screen 1" off the bottom of the bucket to keep hot bits from melting thru the bottom. For best colors, get the parts from crucible to bath with as little exposure to the air as possible.

[A.Merrill]

    I have never tried this but would like to give it a shot. What is something cheap I can use for a cubicle and where do you get the bone stuff.... Thanks.     Al

[CARROLLCO]

Could you use 4' or 6" pipe X 6 "- 8" tall,  threaded on one with an end cap on the threaded end and flat plate on the top? Sounds like this might work for small parts.

[Clark Badgett]

Could you use 4' or 6" pipe X 6 "- 8" tall,  threaded on one with an end cap on the threaded end and flat plate on the top? Sounds like this might work for small parts.

It would. The OP seems to have used a piece of box tube with welded end for his crusible.

[James Wilson Everett]

Guys,

I make my bone charcoal from a box of bone meal that you can buy at a garden center, it looks like bone that is ground to a coarse granular - like Fg powder.  I turn the bone meal and leather into charcoal just the same way as making char cloth.  Put it into a sealed metal container with a couple of small holes in the top, toss it into the coals of a campfire and wait until the smoke stops coming out, take it out of the campfire and wait until it cools before opening the container.  The mix I use for case hardening is 1/3 hardwood charcoal, 1/3 bone charcoal and 1/3 leather charcoal.  This mix does a good job of hardening, but I certainly never got those beautiful colors on my parts.  Thanks for posting, nice work, very interesting and outstanding colors, beautiful.

Jim

[Clark Badgett]

So would this method be a good way to harden and color the lockplate, hammer and frizzen?

[James Wilson Everett]

Guys,

Once I did the quenching as Acer shows in the picture of his post.  However, I was not wearing the protective gear that you see him wearing;  Yikes, that was a major bonehead move!  So, if you try quenching directly from the crucible, be absolutely sure to wear protective gear just like Acer.  I ended up with some steam scalds on my wrists (I did have short gloves on) and on my face.  No permanent damage, but a tough lesson that I will not forget.

Now I quench in a separate operation.  After the crucible has been hot for an hour or so, I remove it from the fire and let it cool.  Then I heat & quench the parts individually just like they were made from a hardenable steel like 1095.  It works OK.  I think than most of the steam flash I encountered was from the red hot charcoal, not from the metal.  Lesson learned.

Jim

[Curtis]

Good info to know, Jim!

[Kermit]

Okay, dummy here is missing something. If pure water is used, nothing added, why this?

"Just before dropping the part in the water I poured the water from one bucket to another and back just to stir it up, I feel this is important to the process."

 

[d-a]

Okay, dummy here is missing something. If pure water is used, nothing added, why this?

"Just before dropping the part in the water I poured the water from one bucket to another and back just to stir it up, I feel this is important to the process."

 

For agitation I would assume. Some guys use an air stone in there water to give more agitation and supposedly more colors.

d-a

[T*O*F]

Regarding colors:
If you heat a piece of polished metal it will go thru various colors as it gets hotter.  The paler colors are at the top of the heat range.

When you quench a piece of red hot metal, the reverse action occurs.  The thinner sections will cool faster and freeze at paler colors.  The thicker sections will cool slower and freeze at the darker (blue) colors.

How, if anything, do all these voodoo methods and formulas alter this physical process to achieve colors?

[d-a]

Regarding colors:
If you heat a piece of polished metal it will go thru various colors as it gets hotter.  The paler colors are at the top of the heat range.

When you quench a piece of red hot metal, the reverse action occurs.  The thinner sections will cool faster and freeze at paler colors.  The thicker sections will cool slower and freeze at the darker (blue) colors.

How, if anything, do all these voodoo methods and formulas alter this physical process to achieve colors?

Could you describe your method of color case hardening and possible picture of your results?

I'm researching this at the moment and taking notes so I can try and duplicate results. All of my current attempts have produced a hardened piece but lacked colors except a dull grey.

d-a

[Nordnecker]

Here's the deal: The reasonong behind case hardening is to harden the metal, not to make pretty colors. The colors are secondary. Think about the process. It's easier to forge "soft" steel or iron into a desired shape than it is to forge tool steel (hardenable by quenching). The soft steel or iron won't harden no matter how you quench or temper it, but it will harden on the outside by "case hardening".
On the other hand, let's say you've successfully forged a frizzen to shape out of tool steel. You want to file it and make it look good and get rid of all the black/scale from the forge. Well, I hope you didn't let it cool too fast because it'll be a bear to file. So, you didn't and now it's all filed pretty, but it's too soft. You stick it back in the forge and get it hot enough to quench, now it's full of hard scale again.
So forging the part out of softer material, then case hardening it is actually easier.
The colors peolple refer to are confusing in that when metal heats up in the forge, it goes from black to dull red to orange to yellow to white to sparks. These colors range from room temperature up to about 2100 degrees fnht. Tempering colors are totally different. To see tempering colors the metal must be polished. The colors go from light straw to dark straw to brown with purple spots to possum ear blue to dark blue to grey, and range from about 400 degrees to maybe 650 or 700. Grey is back to being pretty soft.
"Case" colors are different still and I have not messed around with the process enough to contribute anything of value to this discussion.