Propane to replace electric heat treat?

[thunderskunk]

We heat treat parts in electric ovens with omron controls and such. Is propane fired heat treat ovens with PLC temperature control common for industrial purposes? Google seems to think I’m trying to become a blacksmith and that my parts fit inside a match box. I’m not seeing much on auction sites either, which is usually a good sign that it’s not so popular.

 

[Ries]

Depends. Some alloys will react poorly to the atmosphere from propane. A lot of my friends who actually are blacksmiths, who are treating specific alloys for precise amounts of time at precise temps, use inert gas filled electrics. Or there are some bigger, more expensive tunnel ovens that use gas but are oxygen free. My guess is its simpler and easier for you to stick to electric, but really depends on application. sadly, my friend who really knew this stuff inside and out just died suddenly so I cant ask him.

 

[rons]

Watching Forged in Fire episodes. The forge room uses gas fired kilns for knife making.
When they go outside to use coal forges it is like the old days.
Japanese sword masters heat their metal in a coal-like forge. They sprinkle secret stuff in there to get a five body sword.

In my opinion, heat is heat.

 

[john.k]

More likely natural gas from a gas main........propane in tanks is expensive............lots of lower heat ovens Ive seen are nat gas fired .....this would include shrink wrap lines ,powder coat ovens , paint baking ovens.........a common replacement in older oil fired furnaces ,as the gas flame can go into the same space as the oil flame.

 

[???]

We had a gas fired oven in the toolroom that used big bottles stored outside. We used to put all the tool steel in a cast iron box filled with charcoal. The charcoal would ensure that no oxygen got to the steel, same idea as wrapping in foil or paper etc. We only really used this for rush repair jobs on stamping dies, everything else was sent out for hardening.

 

[boslab]

There are industrial LNG furnaces for heat treatment obviously, they are a bit harder to modulate, in that you need a gas valve to do the modulation ( like a Honeywell off a combi boiler I guess)
Electric ovens are far easier to control imho
Mark

 

[Ries]

again- there are a bunch of different kinds of heat treating.
"heat" is not heat.
otherwise, there would not be entire industries that manufacture atmospheric furnaces, vacuum furnaces, or other controlled atmosphere devices and procedures. Most of which cost serious money.

Some materials, to achieve some outcomes, can be done in a backyard barbecue, or with a plumbers torch. Others need more precise procedures to get desired results.
What are you heat treating? what alloys, what is the required result? are you worried about scale, or hardness, or warping?

Heat treating is an art, which includes science, but sure doesnt end there.

And "forged in fire" is largely bozos who are pretty clueless, although at least 3 buddies of mine have won, including my friend who recently died, and, by and large, they won by shooting fish in a barrel, competing against guys who believed that metal is metal and heat is heat.
The guys I know who really know about heat treating usually have 3 or 4 different ways of doing it, and years of experimenting with alloys that are actually available, and have failed a lot of times first.
This is not button pushing.

 

[thunderskunk]

We had a gas fired oven in the toolroom that used big bottles stored outside. We used to put all the tool steel in a cast iron box filled with charcoal. The charcoal would ensure that no oxygen got to the steel, same idea as wrapping in foil or paper etc. We only really used this for rush repair jobs on stamping dies, everything else was sent out for hardening.

We wrap a few different parts in tin foil as well. Never heard of the charcoal, that’s interesting.

More likely natural gas from a gas main........propane in tanks is expensive............lots of lower heat ovens Ive seen are nat gas fired .....this would include shrink wrap lines ,powder coat ovens , paint baking ovens.........a common replacement in older oil fired furnaces ,as the gas flame can go into the same space as the oil flame.

No gas main up here, haha. The reason I’m looking is because we’re out in the middle of nowhere. I’m looking at tuning a Tsugami TMA8 on a 220v phase perfect converter, which pretty much maxes out my 200A service. Electric furnaces would not help my case.

We do A6, S7, 1045/1044, 1060, a few others. We’re not usually worried about scale; we have a shot peen process after the fact.

 

[rons]

again- there are a bunch of different kinds of heat treating.
"heat" is not heat.
otherwise, there would not be entire industries that manufacture atmospheric furnaces, vacuum furnaces, or other controlled atmosphere devices and procedures. Most of which cost serious money.

Some materials, to achieve some outcomes, can be done in a backyard barbecue, or with a plumbers torch. Others need more precise procedures to get desired results.
What are you heat treating? what alloys, what is the required result? are you worried about scale, or hardness, or warping?

Heat treating is an art, which includes science, but sure doesnt end there.

And "forged in fire" is largely bozos who are pretty clueless, although at least 3 buddies of mine have won, including my friend who recently died, and, by and large, they won by shooting fish in a barrel, competing against guys who believed that metal is metal and heat is heat.
The guys I know who really know about heat treating usually have 3 or 4 different ways of doing it, and years of experimenting with alloys that are actually available, and have failed a lot of times first.
This is not button pushing.

I'm glad I didn't pay for view with forged in fire.
Learned a few things but working under their time clock would make most look like bozos.

 

[Archer120x]

We wrap a few different parts in tin foil as well. Never heard of the charcoal, that’s interesting.

No gas main up here, haha. The reason I’m looking is because we’re out in the middle of nowhere. I’m looking at tuning a Tsugami TMA8 on a 220v phase perfect converter, which pretty much maxes out my 200A service. Electric furnaces would not help my case.

We do A6, S7, 1045/1044, 1060, a few others. We’re not usually worried about scale; we have a shot peen process after the fact.

How do you like the Tsugami TMA8?

 

[john.k]

Why would you run an oven off a phase converter ?..............a simple re-connection of the resistance elements for whatever voltage you have available.

 

[thunderskunk]

Why would you run an oven off a phase converter ?..............a simple re-connection of the resistance elements for whatever voltage you have available.

No sorry, I just meant the amperage of the machine/efficiency loss from phase converter maxes out my available power. We have a few varieties of electric furnace across the main shop, but we have two 400A service entrances. The place I’m trying to stick a furnace is up a mountain in essentially a forest district.

 

[4GSR]

I picked up a small used electric oven a while back. The inside dimension of the oven is about 8 x 8 x 12". It's old! Guessing 50's for sure. Says it uses 3400 watts on 220V single phase, produces 1800°F heat. If my math is correct, that is pulling 14 amps on 240 volts I have available. Now how long will it take to heat up a chunk of iron? IDK. Not planning on doing any serious heat treatment, I got it mainly for annealing some of this high heat-treated iron I have laying around to make it a little easier to cut on.

 

[john.k]

I got few electric 1200C ovens in the back yard .....I scrapped the controll cabinets last year .......cant scrap the ovens ,cause the yard wont pay for firebricks ............I couldnt sell electric furnaces 30 years ago when power was a fraction of the cost it is now .