Hot and Cold

[greenergrass]

Do to my work I can't burn 24/7. But I do burn everyday while I'm Home. I was wandering if it is ok to get a stove hot and then cold over and over everyday. On the weekends I do burn all day and night.

 

[MountainStoveGuy]

that would be normal operation, its abnormal that some of us burn 24/7

 

[wg_bent]

What kind of stove do you have?

From my operation, even 24/7 as it's been for weeks not, the stove does not stay at a constant temp. Depending on the stage of the fire and amount of attention the stove gets during the day, it cycles some anyway. Stoves like the big CAT VC stoves will burn longer with more constant temps, and so will soapstone stoves, just due to the heat retention properties, so maybe you might look at bigger longer burning stoves if you need to be running 24/7.

 

[Rhone]

If your stove is steel, the constant heating and cooling makes it stronger. It's called tempering, like Samurai swords are repeatedly heated and cooled to make them stronger.

That's how I'm using mine even if I'm home. When I light a fire if it's 25F+ outside I'll raise the temp of my house anywhere from 10-14F at the minimum load, minimum air setting I can set (big insert in a small house). So, I pretty much light a fire on an as needed basis, maintaining it 24/7 I'll overheat the house. When it's 0F or less outside that's when I can just about have a fire going 24/7, loading it up every 8 hours.

 

[Andre B.]

If your stove is steel, the constant heating and cooling makes it stronger. It's called tempering, like Samurai swords are repeatedly heated and cooled to make them stronger.

I have been going to start a thread on this but it fits here so.

When my stove, steel, was new it would do a lot of pinging and popping when heating up and cooling down. It has been in use for almost 3 months and just the other day I noticed that it no longer makes those noises. So I guess it is all stress relieved, I think at least some of the manufactures run the weldments thru a stress relieve heat treatment but many repeated cycles does a much better job.

 

[babalu87]

You think a stove goes through extremes.

Look at an engine , especially in a COLD climate.

The cast iron in those things took/take beatings for years and years.

 

[Martin Strand III]

If your stove is steel, the constant heating and cooling makes it stronger. It's called tempering, like Samurai swords are repeatedly heated and cooled to make them stronger.

That's how I'm using mine even if I'm home. When I light a fire if it's 25F+ outside I'll raise the temp of my house anywhere from 10-14F at the minimum load, minimum air setting I can set (big insert in a small house). So, I pretty much light a fire on an as needed basis, maintaining it 24/7 I'll overheat the house. When it's 0F or less outside that's when I can just about have a fire going 24/7, loading it up every 8 hours.

May I make a correction?

"Tempering" metal is heating it to some critical temperature, usually red hot, followed by rapid cooling to fix it in a hardened state.

"Annealing" metal is likewise heating it to a critical temperature followed by slow cooling thus giving the metal a soft layered crystalline structure which improves its machinability and cold working properties.

Either of these terms may not be directly applicable to wood burning metal stoves. Probably, some of each occurs. Regardless, the cyclic heating/cooling of wood fired metal stoves is called "thermal cycling" which has a destructive affect on the stove and, eventually, makes it and/or its components wear out.

So, by firing your metal stove, you are, sadly but surely, contributing to its eventual demise (not helping it get "stronger").

Aye,
Marty

Grandma used to say, "The devil is in the details."

 

[Rhone]

My old steel stove that used to have metal pipes where water ran through the firebox were constantly heated & cooled by the fire. The pipes lasted about 2 years in that environment and then had to be replaced. I always figured it was because of all the heating & cooling, but to take them off I used a breaker bar with a 6 foot pole attachment to break the bolts off, even then they didn't go without a heck of a fight. After the second replacement of those pipes, I had a plumber repipe the system to bypass them so I wouldn't have to remove them anymore. I always figured it was from the constant heating/cooling that made them so damn tough. Marty S knows a more about that kind of stuff than I, so Annealing it is. Learn something new everyday.

Don't worry too much about the metal and heating/cooling taking the life away. That steel stove I mentioned above was used in my old house every winter and it's 30 years old now, still being used as the main source of heat, and has probably another decade or more. That was when the stoves were built with pretty thin steel I think (around 1975 is when I got it). Not to say, that maybe todays steel is thinner. I know todays have thicker tops at a minimum. If it does lower the life expectancy it doesn't seem to lower it much. That steel stove used constantly is still going strong, I've seen 40 year+ old cast iron ones still going strong as well.

 

[Andre B.]

May I make a correction?

"Tempering" metal is heating it to some critical temperature, usually red hot, followed by rapid cooling to fix it in a hardened state.

"Annealing" metal is likewise heating it to a critical temperature followed by slow cooling thus giving the metal a soft layered crystalline structure which improves its machinability and cold working properties.

Either of these terms may not be directly applicable to wood burning metal stoves. Probably, some of each occurs. Regardless, the cyclic heating/cooling of wood fired metal stoves is called "thermal cycling" which has a destructive affect on the stove and, eventually, makes it and/or its components wear out.

So, by firing your metal stove, you are, sadly but surely, contributing to its eventual demise (not helping it get "stronger").

Aye,
Marty

Grandma used to say, "The devil is in the details."

May I correct your correction?

All of these are known as heat treating processes.

Hardening: is a heat treating process to make the metal fully hard, you cannot normally, accurately take metal up to a certain hardness its all or nothing and the metal is often very brittle at this point.

Tempering: is taking fully hardened metal down to the hardness you want, making it hard enough to do the job while not so brittle it breaks.

Annealing: is tempering to the point the metal is as soft as it can get.

Stress reliving: is controlled heating and cooling for the purpose of relieving stresses put into the metal from casting, welding, forming, etc.. This makes the metal more predictable and less likely to fail in use. I would say tougher rather then stronger but both words work.

Continued "thermal cycling" can be destructive but it is exponential with the temperature, normal low temp cycling can go on for a very long time with little effect while higher temperatures have an effect much sooner. Also the speed with which the temperature changes and how evenly the part is heated have a big impact.

 

[Martin Strand III]

May I make a correction?

"Tempering" metal is heating it to some critical temperature, usually red hot, followed by rapid cooling to fix it in a hardened state.

"Annealing" metal is likewise heating it to a critical temperature followed by slow cooling thus giving the metal a soft layered crystalline structure which improves its machinability and cold working properties.

Either of these terms may not be directly applicable to wood burning metal stoves. Probably, some of each occurs. Regardless, the cyclic heating/cooling of wood fired metal stoves is called "thermal cycling" which has a destructive affect on the stove and, eventually, makes it and/or its components wear out.

So, by firing your metal stove, you are, sadly but surely, contributing to its eventual demise (not helping it get "stronger").

Aye,
Marty

Grandma used to say, "The devil is in the details."

May I correct your correction?

All of these are known as heat treating processes.

Hardening: is a heat treating process to make the metal fully hard, you cannot normally, accurately take metal up to a certain hardness its all or nothing and the metal is often very brittle at this point.

Tempering: is taking fully hardened metal down to the hardness you want, making it hard enough to do the job while not so brittle it breaks.

Annealing: is tempering to the point the metal is as soft as it can get.

Stress reliving: is controlled heating and cooling for the purpose of relieving stresses put into the metal from casting, welding, forming, etc.. This makes the metal more predictable and less likely to fail in use. I would say tougher rather then stronger but both words work.

Continued "thermal cycling" can be destructive but it is exponential with the temperature, normal low temp cycling can go on for a very long time with little effect while higher temperatures have an effect much sooner. Also the speed with which the temperature changes and how evenly the part is heated have a big impact.

Thank you. But, don't stop now you have my attention...

So, which of these heating "treatments" apply to a wood/coal/pellet/corn/dung burning metal stove and to what extent?

Eah,
marty

 

[Andre B.]

Thank you. But, don't stop now you have my attention...

So, which of these heating "treatments" apply to a wood/coal/pellet/corn/dung burning metal stove and to what extent?

Eah,
marty

Not sure which direction this is headed. :gulp:

 

[Homefire]

Do to my work I can't burn 24/7. But I do burn everyday while I'm Home. I was wandering if it is ok to get a stove hot and then cold over and over everyday. On the weekends I do burn all day and night.

My God man ,
You mean your intentionally lighting fires in your
wood stove?

 

[Martin Strand III]

Thank you. But, don't stop now you have my attention...

So, which of these heating "treatments" apply to a wood/coal/pellet/corn/dung burning metal stove and to what extent?

Eah,
marty

Not sure which direction this is headed. :gulp:

Buck up my friend. Just looking for applicable information to put in my learning pouch.

Have you an applicable contribution or were you merely spewing out some quasi relative rat facts?

Eah,
Marty

 

[Andre B.]

Have you an applicable contribution or were you merely spewing out some quasi relative rat facts?

Eah,
Marty

That's where I though it was headed.

Tempering does not make the steel harder, quite the opposite in fact.
http://www.efunda.com/processes/heat_treat/introduction/heat_treatments.cfm

 

[Roospike]

Some good reading for thos looking into the subject. Little extreme for woodstoves but you;ll get the idea.


Heat Treatment of Tool Steels
(broken link removed to http://www.crucibleservice.com/eselector/general/generalpart2.htm)

Hardening and Tempering
http://www.anvilfire.com/FAQs/heat_faq_index.htm

Heat Treatment
http://www.navaching.com/forge/heattreat.htm

Heat treatment of tool steels By Ed Tarney,
(broken link removed to http://www.manufacturingcenter.com/tooling/archives/0500/0500tn.asp)

Heat Treating
http://www.dfoggknives.com/hardening.htm

 

[Marty]

Do to my work I can't burn 24/7. But I do burn everyday while I'm Home. I was wandering if it is ok to get a stove hot and then cold over and over everyday. On the weekends I do burn all day and night.

My God man ,
You mean your intentionally lighting fires in your
wood stove?

ROFLMAO

 

[Martin Strand III]

Have you an applicable contribution or were you merely spewing out some quasi relative rat facts?

Eah,
Marty

That's where I though it was headed.

Tempering does not make the steel harder, quite the opposite in fact.
http://www.efunda.com/processes/heat_treat/introduction/heat_treatments.cfm

OK. You have the rat facts and I admit, coming from a bikini waxing background, this 'hardened' talk is not my field...

But, as I asked (politely), how do these processes relate to a wood stove?

Eah ?,
Marty