Is Soapstone really all that?

[MarkTaylor]

Have a basic Drolet woodstove. Would like to throw a slab of stone on top of the stove to slow down the heat transfer into the room (ie, faking the behavior of the VT bun baker or a masonry stove.
Would a 2" slap of limestone on top of the stove be worth my time? Soapstone has to be imported around here but limestone is abundant. Their specific heat capacities seem about the same order of magnitude...
https://solitaire.onl/ 9apps.ooo/

 

[MAD MARK]

I have a slab on mine. Use it mostly to cook on so not to scratch surface top.

 

[MAD MARK]

And as far as I know it hasnt slowed any heat transfer down, but that is with open sides and convection deck.

 

[electrathon]

There are two directions for the heat from the fire to go, into the room and up the chimney. If it is not going into the room, you are redirecting it up the chimney. The stone can only absorb the fires heat at a slow rate, what is not absorbed goes up and out. If you are having trouble with the heat overheating the room at start up of the fire cycle and you want less heat, it is likely a good idea. If you are wanting room heat, do not add an insulating layer to the top.

 

[Highbeam]

As another stone stove owner (previous stove) I found the material to be more harm than good. It looks nice for sure.

 

[Grizzerbear]

Limestone as far as i know tends to be pretty brittle crap. I would think it would crack easily from heat and end up being a mess. If it is manufactured/store bought maybe it is of better quality but i dont think i would mess with it still yet.

 

[Mech e]

That would raise the top surface steel temperature quite a bit. Not sure that is a good idea.

 

[begreen]

That would raise the top surface steel temperature quite a bit. Not sure that is a good idea.

How so?

 

[Mech e]

When the top of the stove reaches thermal equilibrium, it is relying on radiation and natural convection to dissipate heat. By placing a piece of stone over the top of the stove the heat transfer changes to conduction into the stone. The stone is a poor thermal conductor (about 25% of steel) and also thicker than the steel. In addition, the thermal connection between the stone and the steel is poor, allowing for many air gaps between the two surfaces. Air is an excellent thermal insulator. So between the air gap and the stone, a "blanket" has essentially been put on the top of the stove. To dissipate the same amount of thermal energy from the top of the stove, higher temperatures will be required to push the energy through the air gap and the stone. Hope I have explained that clearly.

 

[firefighterjake]

Have a basic Drolet woodstove. Would like to throw a slab of stone on top of the stove to slow down the heat transfer into the room (ie, faking the behavior of the VT bun baker or a masonry stove.
Would a 2" slap of limestone on top of the stove be worth my time? Soapstone has to be imported around here but limestone is abundant. Their specific heat capacities seem about the same order of magnitude...

I think it was back in 2009 I did this with soapstone. Bought a slab from a counter place and put it on the stove.

It's still on top of the stove . . . I have some feet (slate or granite -- I forget which stone) which raises the soapstone a half inch or so to allow air to circulate from the cast iron stove top underneath.

Truthfully . . . I think it pretties up the stove a bit, but I've noticed no change in heat retention or the stove operation. My conclusion is to get the benefit of a thermal "battery" as you would find in a soapstone stove or Russian fireplace for example one really needs a decent amount of material . . . and a relatively small, thin piece of stone just won't cut it.

 

[jetsam]

Soapstone has nowhere near the thermal conductivity of steel. People and companies talk about it like it's a great conductor of heat, but this just means they can't be arsed to look it up / think about it / test it themselves. Even the (probably inflated) claims of soapstone's thermal conductivity from companies that make soapstone stoves put it at a fraction of the conductivity of steel.

Can you heat a house with a soapstone stove? Sure. You can also heat a house with a steel stove that you've wrapped in fiberglass insulation.

There was a very strong case for masonry stoves with small fireboxes back in the day before EPA stoves forced everyone to have a secondary burn (and they remain nice heaters to this day). You burn a hot fire in the small firebox, which forced you to burn as hot as possible, which increased your fuel efficiency in the absence of a reburn system. Some of the heat from that small fire made it through the masonry, and the high thermal capacity of the stone meant that it would keep emitting a little heat long after the fire had gone out. In the era of stoves with very poor air controls, this made a whole lot of sense.

Today? More expensive, doesn't work as well.

 

[webby3650]

I mentioned on another forum that soapstone was a great insulator, poor conductor. Also how I felt doing this is not only preventing heat from leaving the stove, but could possibly overheat the steel/secondary combustion components. It sure got all the soapstone nuts over there in an uproar!

 

[CentralVAWoodHeat]

I mentioned on another forum that soapstone was a great insulator, poor conductor. Also how I felt doing this is not only preventing heat from leaving the stove, but could possibly overheat the steel/secondary combustion components. It sure got all the soapstone nuts over there in an uproar!

I also posted about doing this a while back on my Castine. The soapstone insulated the stove and increased the stove temps on the sides of the stove since it insulated heat escaping from the top.

We live very close to an open soapstone mine so a lot of things in our home, including our hearth are built of soapstone. It has its applications but I can say, under heat, it cracks very easily.

 

[begreen]

This is why l like cast-iron jacketed stoves. Good heat retention without any of the drawbacks or worries.

 

[Badams1989]

I just installed a Hearthstone Phoenix as a replacement for a 1970’s Salvo Citation wood/ coal combo. I’m still getting quite a bit heat out of this stove long after my other stove would be cold, Ice cold. Here come the nay sayers “ it takes longer to heat the stone so the results are the same. “ ok fine.. I’m not waking up twice a night to stock the new stove though, I know I’ll be getting heat well into the morning. Soapstone works very well for me.


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[webby3650]

I just installed a Hearthstone Phoenix as a replacement for a 1970’s Salvo Citation wood/ coal combo. I’m still getting quite a bit heat out of this stove long after my other stove would be cold, Ice cold. Here come the nay sayers “ it takes longer to heat the stone so the results are the same. “ ok fine.. I’m not waking up twice a night to stock the new stove though, I know I’ll be getting heat well into the morning. Soapstone works very well for me.


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I’m glad it’s working out for you. The Phoenix is only half soapstone, only the top and the sides are stone. There’s a lot of cast iron there to make good heat.

Pretty much everyone here makes it through the night easily without reloading with a modern stove.

 

[Badams1989]

I’m glad it’s working out for you. The Phoenix is only half soapstone, only the top and the sides are stone. There’s a lot of cast iron there to make good heat.

Pretty much everyone here makes it through the night easily without reloading with a modern stove.

Using a stove that was 40+ years old was becoming exhausting . It was my fathers old stove so I think that played a big part in why I kept using it. I’m using it to heat my garage now.


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