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+--- Thread: Case Hardening with a Charcoal Furnace (/thread-3117.html)
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RE: Case Hardening with a Charcoal Furnace - Pete O - 03-14-2016
Really enjoyed that video Tom, I can see another use for my oil-fired furnace.
Back when I was 20-something I made an attempt at case-hardening with a similar compound, using an oxy-acetylene torch for heat. Ended up with an empty oxy set and a ruined part.
RE: Case Hardening with a Charcoal Furnace - TomG - 03-14-2016
Thanks Pete.
The secret is to keep oxygen away from the part. These were close to being ruined due to the rupture of the foil. Looking back, I noticed some white smoke coming out of the furnace toward the end and that must have been when the leak started.
Tom
RE: Case Hardening with a Charcoal Furnace - Mayhem - 03-14-2016
Do you think it was the direct air blast that did it? Looking at your video it seemed that the bottom gave way.
The stuff I see on eBay is listed as 0.02mm thick which is about 0.0008". I can't see that holding up to heating up a pie in the oven, let alone heat treating a part...
RE: Case Hardening with a Charcoal Furnace - TomG - 03-14-2016
Maybe. Perhaps it should be double wrapped or set on a plate. Of course there is always the option of putting the parts in a steel box.
Tom
RE: Case Hardening with a Charcoal Furnace - EdK - 03-14-2016
(03-14-2016, 09:53 AM)TomG Wrote: Perhaps it should be double wrapped
That's what I was thinking also.
Ed
RE: Case Hardening with a Charcoal Furnace - awemawson - 03-14-2016
Back in the day, parts would be packed into an iron box with the carbon compounds and a few shavings of wood. The box lid was reasonably tight fitting and retained with a twist of iron wire - the shavings burnt up and exhausted the oxygen from within the box. Knock out was a case of lifting the box from the Furness, knocking the contents out and dunking them.
I too have used the stainless foil and as Tom said, it's razor sharp - mine must be a bit thicker than the stuff Tom was using as it doesn't burn through, but it's the very devil to get the parts out while still hot enough to quench.
I reckon a box is the way forwards.
RE: Case Hardening with a Charcoal Furnace - Old Minger - 03-14-2016
Great video Tom, thanks for the time and effort.
John
RE: Case Hardening with a Charcoal Furnace - DaveH - 03-14-2016
Very nice video Tom
daveH