Crucibles for caseharding

[Jim Filipski]

Hi Folks,
 Thought I would ask about what type of crucibles everyone is using for casehardening. I hope we get a few good ideas passed around
Thanks
Jim

[Acer Saccharum]

I use a piece of 3" steel water pipe, end welded up with 1/4" plate. Open end is machine flat, and then another disk is machined with a rim to fit flat. Helps a lot to have a lathe and a welder.

Sometimes for small jobs I use a tuna can with the cut out lid for packing. Use once and toss.

[Dave B]

I have not done any my self but several of the guys out our way are using steel containers of well casing or square tubing welded up on one end and 4-6" across. The whole container is dropped into the quench by some. one uses a cross pin that when pulled the lid drops away dropping just the lid and the contents of the container. The first method results in a large spray from the steam. Make sure your not to close to your neighbors house when you do it.

[J.D.]

I have a 3" id, heavy wall pipe welded on one end, as others have described.

I am having a 3 1/2 X 3" X 8 " long box made of 1/4 " plate for hardening lockplates.

A pair of long handle tongs with long bits is being made to fit the box.

The sides of the box are designed for 2 pieces of 3/8" angle iron to be welded near the top and bottom, of each side,  to prevent the tongs from slipping off of the box.

I found a pair on looooonnnngg, about 28 " handle, pick up tongs at a junk shop for 9 bucks. I can't make 'em for that, and grabbed 'em as soon as I saw the price.

The bits are pretty long; long enough to grip the 3" dia crucible securely , with a little modification.

My limited experience in pack hardening suggests that long reigns on the tongs used to remove the crucible from the fire is a real good thing...or real heavy welding gloves...and in some situations, both.

God bless,
J.D.

[jerrywh]

 Even a tin can will work for one time. just set a flat plate on top. but keep it covered. you don't want the top to come off when it is in the fire or oven. I case hardened frizzens in baby food cans for years in a wood stove.

[Swampwalker]

I've thought of, but havn't yet tried, used (empty) camp propane bottles.  Cut the top off, use a flat metal plate for the lid.  Essentially free, and should be good for a few heats.

[Jim Filipski]

Most times I use a tin can container ( crimped closed) of various sizes (disposable) for lack of a permanent crucible. I find that by the time the parts are ready for quench...using two long handle tongs, I can position the container right above the water bath and break it open & instantly drop in to the quench
Jim

[Acer Saccharum]

I'm adding 'Tongs' to my list of things to shop for. Good idea.

Acer

[44-henry]

I posted this in the last thread on casehardening, but it would probably fit better here.

Here's a couple photos of the crucible that I have been using for the last couple years at the university where I teach.



Here are a couple shots of the crucible in use.





Heres the setup we were using, but I've recently gone to a sturdier tank with an air line and also the larger kiln sold by Brownells.



If you want to watch the video clip I did of one of my students going over the process it will probably explain how we use the crucible. We get good results using this method and you don't have to drop the whole crucible into the water to do it (something I try to avoid). With this method the bottom of the crucible is only about 1/4" (often less) above the surface of the water at the time of the quench and it is very quick and consistent (I have 30-40 students each semester who do the same process with repeatable results).

Here is the link to the video.

[J.D.]

I've thought of, but havn't yet tried, used (empty) camp propane bottles.  Cut the top off, use a flat metal plate for the lid.  Essentially free, and should be good for a few heats.

Great minds think alike. 

I have used propane bottles, cut off at the seam, several times. The base seems to burn through pretty quickly, but the bottom of the bottle holds up pretty well.

I tried to extend the life of the propane crucible by cutting the top half of the bottle to slip over the bottom half, for a double thickness. The sleeve had to be cut lengthwise to fit. The sleeve does seem to prolong the life of the crucible when slid down to cover the bottom.

That said, I just made a new crucible from scrounged 3 1/2 " heavy wall pipe and 3/8 plate. I think the longer lasting crucible is the way to go if you plan to do very much pack hardening. IMHO, it's about the only way to get a good, deep case. I sometimes get colors too. 

God bless,
J.D.

[jerrywh]

Be very careful if you drop the whole container into the water upside down. Steam inside the cotainer will blow it out of the water. I had one blow about 8 feet in the air once. I never drop the box or container in the water any more. I just case hardened the last two days. small parts. Two sideplate screws with gold damascene on them and a pistol set trigger and plate. They are now being normalized . When they come out of the oven I will get some photos.  The heads of the screws will be temper blued to show off the gold.
 PS. I have had steam blow small parts back out onto the floor also when dropping the container into the water. It isn't fun hunting for a tumbler fly in the grass.
  JUST OUT

[J.D.]

Dang Jerry, that is outright gorgeous. Ya gotta love the contrast between the gold and blue.

[Robby]

WOW!!