charcoal pack case hardening

[Phil Coffins]

MD, I only go as high as 1400* and lower my temp till it’s stable at 1350* before quench. No rest is given other then the few seconds it takes to pull the crucible, turn and dump in the water.
I like your colors and I’m glad you opened this subject. I don’t type well so my responses will be short.

 

[rkcohen]

ok - where is your tutorial? this is facinating to be able to execute small parts!

 

[Phil Coffins]

Tutorial? I ain’t got no tutorials, you don’t need no stinking tutorials!
Add a bucket of water and here’s the basic gear used for one nose cap shown above.
IMG_0572 by Oliver Sudden, on Flickr

 

[longcruise]

Tutorial? I ain’t got no tutorials, you don’t need no stinking tutorials!
Add a bucket of water and here’s the basic gear used for one nose cap shown above.
IMG_0572 by Oliver Sudden, on Flickr

Phil, how do you track the temperatures in the fire?

An old topic but very interesting.

 

[Phil Coffins]

I just watched it, the crucible got to a dull red in the evening light and in about an hour after finishing a cocktail I quenched the contents. On such a simple piece as the cast nose cap you would have to try to mess it up. Like many thing we do in life doing it and paying attention to the results allows some success. My first parts ever were just mild steel home made tools before any important things. If a fellow wanted to learn how, the most important thing to do is start! If the sole prepose is to get a color cased part it’s better to have it done by someone that has done it. Most of the information is in this thread and a few others.

 

[Col. Batguano]

How expensive would it be to get set up to do this sort of thing? Starting from square 1.

 

[Phil Coffins]

In about 2004 I bought the furnace from Brownell’s for $1300 and the charcoal from them was about fifty dollars a bucket. I got one of bone and four of wood. Tongs from a fireplace set and crucible’s home made from pipe and tubing. Prices have gone up since then so it’s not a thing I can speak to. As a hobbyist I was able to repay the cost in a few years by doing other peoples needs while doing my hobby jobs. In the ensuing years besides serving my needs (wants) the process has made money but more importantly it allowed me to do the work I wanted.

 

[Tom A Hawk]

Phil, What do you use for the crucible?

 

[Col. Batguano]

Then add in the cost of the proper dunk tank and basket. From what I've seen of the process its very messy. Lots of amps going to an oven that can get that hot, so maybe re-wiring the electric panel too.

The videos on You tube show a pretty big oven that's set up outside. I like the idea of recapturing those BTU's as a thermal byproduct (at least partially) to heat the house, but the mess from the dunk and then dumping the barrel would seem to override that advantage.

Do you aerate the barrel right before or during the dunk part? The Midway video shows that as a part of the process.

How much would you charge someone to do their parts? I expect if you were asked to do all the metal prep that might take 20-30 hours just for the prep part on and old somewhat pitted part. Start with new stuff and the prep part goes down considerably.

The "earn while you learn" part is an attractive concept. That's what lawyers do. Clients pay for their lawyers' education.

 

[Phil Coffins]

Phil, What do you use for the crucible?

Steel pipe and tubing.

Col. the quench tank is a 55 gallon blue plastic barrel that I got for free and I retrieve the parts with a magnet wrapped with cloth on a length of wire. A fish tank bubbler stirs the water and after the job the water is pumped out by a small water fountain pump into the lawn to water the grass. The oven is inside the garage close to the door and the quench out side. Running 220 from the panel to the oven is simple. The char coal can be air dried and used again. The charge for a set of parts that where polished generally came to $200 unless the same person had more then one set then it was less then that per set. These days I only do my parts and occasionally a piece or two for friends.

 

[Col. Batguano]

Thanks Phil. That's a great help.

 

[Tom A Hawk]

Lacking an oven, can this be done effectively in a charcoal forge?

 

[James Kibler]

If your goal is surface hardening over colors, a dull red color isn’t sufficient. In this case I would suggest using a furnace. We target 1525-1550F.

 

[rusticbob]

If your goal is surface hardening over colors, a dull red color isn’t sufficient. In this case I would suggest using a furnace. We target 1525-1550F.

This is the man who should now

 

[IanH]

If your goal is surface hardening over colors, a dull red color isn’t sufficient. In this case I would suggest using a furnace. We target 1525-1550F.

Agreed.

But for color only on non-critical parts, or very critical parts on which you don't want maximum surface hardness but do want maximum color, 1400 is plenty and much less likely to warp things.