cast iron cracks in cold climates?

[jamesk7]

I was planning on buying the jotul F602CB - the guy at the dealer says that cast itron stoves can crack in cold climates and should be started with a small fire to warm up - is this true - winters here can get to well below zero.

 

[begreen]

It's recommended to do a few break in fires with a new cast iron stove, each fire being a little hotter than the last. No big deal and after that only necessary at the beginning of the season if the stove is in regular use throughout the winter.

 

[begreen]

I just caught your other post about the flue. I can see the dealer's concerns if this stove is just going to be used occasionally and started up from very cold and expected to go full blast. It's a tough little stove from Norway, so it is no stranger to the application you have. But a basic steel stove might be a better bet here if you have concerns.

 

[Skier76]

We've got a Castine at our weekend place in VT. We turn the heat down during the week while we're back in the flatlands of CT. I start a fire when we get up there on Friday evenings in the winter. I'd say the lower level(where the stove is located) is usually around 45-50 degrees. I haven't (knock on wood) had any issues with the stove cracking or anything. Now, the "*" is my chimney set up. It's less than ideal. So it does take some time for the fire to get going. Not hours, but on the other hand, I'm not ripping at 600F and turning the air control down within 15 minutes of lighting.

 

[jamesk7]

I just caught your other post about the flue. I can see the dealer's concerns if this stove is just going to be used occasionally and started up from very cold and expected to go full blast. It's a tough little stove from Norway, so it is no stranger to the application you have. But a basic steel stove might be a better bet here if you have concerns.

That is true - norway would have a very similar climate - 6 months of frozen solid - do you have any recomendations on small steel stoves - I notice they get big fast - and with 200 sg ft I don't want a sauna. (I notice Drolet sells a little stove called the Pyropak, but 15"clearances vs. the Jotuls 9")

Thanks for your help.

 

[Jags]

Auto brakes and engine manifold seem to hold up quite well going from very cold to very hot - quickly. Both are/were made from cast. And that engine manifold will gain temp at a much higher rate than starting a fire in a cold stove.

 

[begreen]

For steel, maybe take a look at this guy: http://overstockstoves.com/50tvl17—epa-certified-noncatalytic-wood-stove—1250171200.html

The Pyropak can have the rear clearance reduced to 5" with an approved, permanent wall shield. Also look at the Napoleon 1100. The square footage requirement is going to be hard to match and a bit irrelevant if you are trying to quickly heat up the place from 0 °F. It will take a while for the mass of the building and furniture to warm up. In warmer weather, just build a smaller fire and let it go out.

 

[spirilis]

ya I wouldn't worry about choosing cast iron over steel based on climate. Jotul makes nice stoves anyhow.

 

[Slow1]

Hmmm... Stove at full bore will have internal temps > 1200*f , surface > 600*f right? If I start my stove when the room is 20*f vs 60*f that is a 40*f difference - so how much difference does that really make here?

I can appreciate the argument of not wanting to heat a given metal too fast, but to make an argument that "xyz is not well suited for a colder climate.." seems odd to me. The metal won't go through a phase change in the temperature ranges you are talking so it is simple expansion rate you are concerned about.

So my point here is if the room you are heating is going to start off really cold so you want it hot quicker and thus are more likely to overfire the stove then you have a problem as that is going to be hard on the stove. Perhaps THAT is the question really - is a cast stove going to be less forgiving of overfiring than a steel stove and/or can you get the steel stove up to higher temps so you can heat that cold room faster? I suspect the answer may be yes based on what I have read here.

I don't think it is a question of the "cast stoves can crack in cold climates" - they can crack in any climate actually. It is a question of will it crack under the use you will be using it - i.e. do you plan to drive it really hard for some reason?

 

[jamesk7]

So if its a matter of starting with a small fire and building it up from there I don't see that as a problem - this discussion has made me aware of it however - my expereince is mainly with old farm cookstoves with rusted out fireeboxes and some single wall pipe through the ceiling - so the thought behind heating with stoves is new to me besides stoke er up and keep er stoked until uyou are finally warm.

Thanks guys - all really helpful posts!

 

[begreen]

I'm not sure if the concern is about the rapid temperature increase or about moisture needing to be baked out of the cast iron after the stove has sat idle for a long period. The 602 can take getting up from cold to 700 easily. We did this daily, winter after winter with our old fellow. And truth be told there were a few times when it went up to 900 on the stove top if you weren't staying on top of it. This stove likes to crank.

But so far, no cracks except for in the back which I replaced. But that was more from the upper baffle being warped allowing the flamepath to go straight out the back and lack of inner burn plate in the back. I think they have added this to the 602CB by way of an air manifold, but would need someone to confirm.

 

[firefighterjake]

I wouldn't worry too much . . . there seem to be a lot of cast iron smoke dragons out there still in use in many a Maine cabin or camp. I would do break in fires for the first few fires . . . and if the stove had sat idle for some time I might not want to load it with a full load of small cedar or pine and touch it off (I would do the normal top down fire to slowly bring it up to temp) . . . but I most definitely wouldn't worry about a cast iron stove cracking in two from the cold.

 

[roddy]

ive got a 602,live in eastern ontario where it can be as cold as anywhere else,no problem with the stove.maybe,though,a top down fire would ease concerns of cold cast cracking,if it is even really a concern
rod

 

[Lucy]

We have an Olso at our cottage 100 kms north of Winnipeg, it is the same temperature inside as outside when we go every second weekend in the winter. If its 30 below outside its 30 below inside, maybe a couple of degrees warmer if it has been a sunny day. Start the stove off slowly and its good to go, no problems with cracking of cast iron or the enamel on the stove. p.s. for those who are wondering and need a reference the cottage is about 350 kms north of Fargo, N.D.

 

[cycloxer]

Unless you fill the stove with an accelerant, you couldn't heat it up fast enough to crack the cast iron.

 

[raiderfan]

So i guess this brings me to my question, right along the line of the OP's : what maintenance can be expected with a cast iron stove? We can already gather it won't crack from starting from cold to hot, too quickly, but do they require any special/major maintenance (other than the obvious of not to overfire the stove) that a steel stove would not?

 

[Jags]

So i guess this brings me to my question, right along the line of the OP's : what maintenance can be expected with a cast iron stove? We can already gather it won't crack from starting from cold to hot, too quickly, but do they require any special/major maintenance (other than the obvious of not to overfire the stove) that a steel stove would not?

You may have to repack the joints with stove cement every 10 years, Gaskets (as with any stove), and possibly baffle or burn tubes (or a cat), but that is not unique to cast. I suspect my stove will outlive me (and I hope I have another good 40 to go).

 

[Battenkiller]

Hmmm... Stove at full bore will have internal temps > 1200*f , surface > 600*f right? If I start my stove when the room is 20*f vs 60*f that is a 40*f difference - so how much difference does that really make here?

My sentiments exactly.


I have always gotten my stoves up to temp as fast as I can. Never had a crack in over 20 years burning. I think I may have warped a steel stove once, a long time ago. I accidentally got the thing redder than Santa Claus.

There is always the quality of the castings to consider as well. Cast iron can vary greatly, both in porosity, composition of the alloy, and in the stresses locked inside it. Several small break-in fires when you first get the stove will help to relieve some of these stresses.

My old stove was a Jotul clone made in Taiwan. I must have gotten a good one because I abused the crap out of mine for 18 years and it never cracked. Not only did I not know for several years that I was supposed to keep the bottom filled with ashes, I routinely shoved ice and snow covered wood into a raging hot box with no ill effect. Others have claimed nightmares with the same make stove. Quality control in Taiwan ain't what it is in Norway.

My VC stove is made of castings from the Randolph, VT foundry. It has a reputation for producing superior castings. Woodstock Stove Co. will be getting it's cast parts from this foundry in the future. They are pretty discriminating folks at Woodstock.

Extremely rapid thermal expansion is bad for cast iron, but it's pretty hard to get it too hot too fast by starting a fire in a stove. Rapid contraction from getting it too cold too fast is a lot easier to accomplish. Place an ice-covered log on a 750º stove top to dry it off and you are asking for trouble. I've seen stuff like that, but in these days of $3000 stoves, folks seem to take better care of them.

 

[webbie]

I think a car engine and manifolds are the ultimate test - cast iron (in many cases) and heat from way below freezing to almost red hot hundreds of times....without cracking.

I think the dealer is either not well educated or is trying to sell you something else.

Sure, if your entire intention it to burn cut off kiln dry 2x4's and particle board (NOPLEASE DON'T) a steel stove is more likely to hold up to it. But given regular wood, a good cast iron stove should last for many decades.

 

[Battenkiller]

I think a car engine and manifolds are the ultimate test - cast iron (in many cases) and heat from way below freezing to almost red hot hundreds of times....without cracking.

Oh, but they do crack, all the time. I've had three Toyotas that developed cracks in the exhaust manifolds. Exhaust manifold temps are usually in the 500-800ºF range (about the mid to extreme range of a wood stove), and engine blocks are either water-cooled or have cooling fins to keep the temps a lot lower than that.

 

[Jags]

Disk brake rotors can go from sub zero to almost red hot in a hard/emergency type stop - within seconds. Failure (actual cracking) of the rotors are very rare compared to the frequency that this happens.

 

[renewablejohn]

I think the dealer might be referring to moisture in the cast iron which leads to rust which allows more moisture in till eventually the cast breaks . It happened to us with a cast iron Efel Toledo stove but only after 15 years we needed to replace the front box panel and eventually after 20 years the remaining cast corners cracked allowing you to see the internal flames but more important allowing the noxious stove gas out. We tried fixing with stove cement but eventually decided that after 20 years of service it was really time for a new stove so we replaced it with a cast iron Dunsley Yorkshire stove and have never regretted it.

 

[Backwoods Savage]

I'll jump on the bandwagon here also. Perhaps if the stove was kept in an outbuilding that was maybe 20 degrees below zero or colder and you lit a roaring fire immediately you might possibly have a concern (because in that outbuilding there would probably be a moisture problem). However, a stove kept in the house and starting a hot fire I doubt you would ever have a problem. We've heated with wood for many, many moons (check my signature line) and have never experienced this. During our time heating with wood we have burned cast stoves, steel stoves and now a soapstone stove. We do not expect to ever have that problem even with the soapstone. btw, this soapstone is the best stove we've ever owned! We burn half the amount of wood we used to and stay much warmer in the home.