# Soapstone replacement for insert firebrick



## SolaGracia (Dec 29, 2009)

Does anyone know if is would be possible/advantageous to replace the factory firebrick in an insert with soapstone shaped as duplicates?

I would like to get longer periods of heat output once the fire dies down for overnight burns.

My insert is the Regency i3100l.


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## Backwoods Savage (Dec 29, 2009)

Welcome to the forum SolaGracia.

I'd stay with firebrick. The key to longer burns is in the wood that you burn.


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## Martin Strand III (Dec 29, 2009)

SolaGracia said:
			
		

> Does anyone know if is would be possible/advantageous to replace the factory firebrick in an insert with soapstone shaped as duplicates?
> 
> I would like to get longer periods of heat output once the fire dies down for overnight burns.
> 
> My insert is the Regency i3100l.



Of course you can replace firebox firebricks with soapstone duplicates.  But, why would you want to?

Here is why I would not do it:

1.  Soapstone is considerably more expensive.
2.  Soapstone is soft compared to firebrick and will get scarred up more easily.
3.  Soapstone has a rather high thermal conductivity compared to (fire)brick (soapstone being some 6 to 7 times more conductive;see below).  This factor alone means *you will LOSE heat faster from your firebox with soapstone* than firebrick.  From a materials standpoint, to retain heat in the stove, the firebox should be INSULATED, not conductive.  This is one of the reasons the Mfg put firebrick in the metal stove in the first place.

*MATERIAL*                   *THERMAL CONDUCTIVITY*
                                                           W/mK      (Btu-in/hr-ft-F)

Cast Iron                                75             (520)
*Soapstone*                          6 - 7         (42 - 48)
Granite                                   3              (20.8)
Face brick                             1.29              (9)
*Firebrick, Clay* (ASTMC62) 0.95             (6.6)

Aye,
Marty
Grandma used to say, "Most likely, you will not have to reinvent the wheel."


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## LLigetfa (Dec 29, 2009)

The reason for firebrick is to be an insulator.  The insulation helps maintain higher internal temperature for more complete combustion.  The reason for soapstone is to be a thermal mass.  This is to even out the highs and lows of the cyclical nature of wood burning.  I think the two are non-interchangeable.


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## Fsappo (Dec 29, 2009)

Hearthstone uses soapstone to line the inside of their fireplace insert.  It will keep the firebox warmer longer than a firebrick lined insert.  It has also proven to be much more durable.  It is softer, so it will scratch, but it's not a beauty contest inside of the stove.  It doesnt seem as brittle as firebrick and I have yet to have to replace one out of dozens of inserts sold.  I have a number of customers tell me that the heat retention is so good that the convection blower doesnt shut down between the time they let the stove burn out for cleaning the ashes and they rekindle the fire.  Also, coupled with the cast iron of the insert, it makes for a very even heat.  I'm sure a Hearthstone dealer could sell you the bricks.  A full set of Clydesdale bricks retails for $200.  Not sure if it's worth the cost to try it.  Money aside, it would be a fun thing to try.


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## Martin Strand III (Dec 29, 2009)

Franks said:
			
		

> Hearthstone uses soapstone to line the inside of their fireplace insert.  It will keep the firebox warmer longer than a firebrick lined insert.  (SNIP)



Gee.  This sounds like a sales pitch and is counterintuitive, considering the physical properties of the two materials.  

Any data to support your claim: "It will keep the firebox warmer longer than a firebrick lined insert."?  The Hearthstone website compares soapstone to cast iron and steel for heat retention ("HeatLife"), not fire brick.

Aye,
Marty


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## Fsappo (Dec 29, 2009)

Right, because I want to sell a box of stone to someone 600 miles away from me.  No Pook, no data, just 25 years of burning wood and customer feedback.  You can go test it at a lab, I'll use experience and common sense.  YOU can try this.  Heat a 4x9x1.5 inch firebrick and a piece of soapstone with a 2 torches for 15 minutes.  Come back 30 minutes later and see which one is warmer.


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## LLigetfa (Dec 29, 2009)

No need to throw stones and no point in getting into a pissing match.  I think if you spoke to the engineers at Hearthstone they'd tell you the soapstone stove was designed from the ground up with the characteristics of soapstone in mind.  If a stove is engineered for firebrick, chances are they are relying on the insulating and reflective properties of the firebrick.  That is why most non-cat EPA stoves will have firebrick on all 5 sides.


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## karri0n (Dec 29, 2009)

Franks said:
			
		

> Right, because I want to sell a box of stone to someone 600 miles away from me.  No Pook, no data, just 25 years of burning wood and customer feedback.  You can go test it at a lab, I'll use experience and common sense.  YOU can try this.  Heat a 4x9x1.5 inch firebrick and a piece of soapstone with a 2 torches for 15 minutes.  Come back 30 minutes later and see which one is warmer.




The soapstone will be warmer, because the firebrick will have done exactly what it's supposed to: reflect the heat.

Lining a steel or CI firebox with soapstone when it is engineered to be lined with firebrick will lower the temperature inside the firebox during the burn, and very well may prevent any secondary burn whatsoever. 

Franks,

I know you've only been on this site for a couple months, so you probably haven't seen Precaud's experiments using different types of refractory inside of fireboxes. The results by and large showed that the lighter the material, along with the higher of the refractory propertes of the material, are what contribute to better temps inside the firebox and greater efficiency of the stove. this is the same reason Quadrafire uses pumice brick as opposed to standard firebrick. Adding thermal mass to the inside of the firebox makes it take that much longer to reach optimum secondary combustion temp. If I recall correctly, the best material that he tested a far as refractory properties and real-world stove temps was Skamol refractory liners, with lightweight pumice bricks coming in at a close second place. Here is the thread:

https://www.hearth.com/econtent/index.php/forums/viewthread/34651/


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## Fsappo (Dec 29, 2009)

Karrion, thanks for the link there.  My only point was that the soapstone would stay hot longer.  Nothing to do with reflecting heat. The OP asked what the pros and cons are.  I never claimed the stove would heat better, just stay hot longer.  LLI, I just get defensive when I offer my opinion and someone accuses me of making a sales pitch.  Wasn't looking for a pissing match.

If you reread my post and find something that I actually wrote that was not factual, let me know what it is and why.


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## SolaGracia (Dec 29, 2009)

Thanks for all the great information.  I understand now the purpose of the firebrick is to insulate.  It makes sense that the Thermal Conductivity would need to be as small as possible for this.  It looks like maybe they tried to balance the coverage of the firebrick in the box?  There are a decent number of square inches not covered by any firebrick at all in my insert.  Presumably this is to provide some path for the heat to the outside?


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## yanksforever (Dec 29, 2009)

So much for all the jealous soapstone haters! ;-)


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## Martin Strand III (Dec 30, 2009)

yanksforever said:
			
		

> So much for all the jealous soapstone haters! ;-)



FYI:

Most of us are not engineers and have no clue of what goes into the R & D of designing and making a wood stove, or any other accessory heating device, burn the best it can.

The stance "I've done it and it works for me and some I know" or "put a torch on it and see which is hotter after a while" is simply retrogressive thinking and may explain why todays metal wood stoves and their fuel source are a dichotomy.

Aye,
Marty


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## Fsappo (Dec 30, 2009)

Most of us also lack reading and comprehension skills.  When a poster says "soapstone will keep a firebox warmer longer", some folks need to read more into it and offer a rebuttal as if the poster said "Soapstone will make any stove burn better and hotter and longer can someone please try to belittle my opinion and use an expanded vocabulary to do so"

You see, when people believe what they read with little or no hands on knowledge of an subject they need to be offered simple experiments to help them understand.  I claimed soapstone will stay hotter longer than firebrick which would keep the firebox warmer for a longer period of time, which it will.  If you couldnt comprehend that, the torch idea is the simplest way I can help you learn.  You need to get your hands a little dirty sometimes.


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## yanksforever (Dec 30, 2009)

Lets face it...Soapstone rules!


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## cycloxer (Dec 30, 2009)

Soapstone is not typically used as an insulator like firebrick. I would not do it. What would you gain? You need to add a lot of soapstone to gain any significant thermal mass.


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## Martin Strand III (Dec 30, 2009)

Franks said:
			
		

> Most of us also lack reading and comprehension skills.  When a poster says "soapstone will keep a firebox warmer longer", some folks need to read more into it and offer a rebuttal as if the poster said "Soapstone will make any stove burn better and hotter and longer can someone please try to belittle my opinion and use an expanded vocabulary to do so"
> 
> You see, when people believe what they read with little or no hands on knowledge of an subject they need to be offered simple experiments to help them understand.  I claimed soapstone will stay hotter longer than firebrick which would keep the firebox warmer for a longer period of time, which it will.  If you couldnt comprehend that, the torch idea is the simplest way I can help you learn.  You need to get your hands a little dirty sometimes.



No offense intended.  Just asked for some (objective) data to support your (subjective) statement. 

I am having difficulty relating a torch, 2 different masonry products and a thermometer to an engineered metal stove with different masonry firebox liners.  This "simple experiment" is missing something: metal.

Is it not logical that soapstone, with more than 6X the thermal conductivity of firebrick, will lose heat faster when placed against a metal, cast iron, which conducts heat some 10X faster than the soapstone than the same comparison using firebrick, which conducts heat some 6X slower than soapstone?

 Experience is a good teacher but it is not the entire story.

Aye,
Marty
PS:  You'd be surprised where my hands have been.


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## Fsappo (Dec 30, 2009)

May not gain much doing that, but it would still be fun to try.  I like to get my hands dirty and experiment.  If those stones werent so expensive I would do it with a model in our showroom.  I did once put about 50lbs of soapstone on top of a quad 3100.  Those stones would still give off heat when the sides of the stove were cool to the touch.  Just some fun stuff and an interesting question.  Here is another question.  If you "replaced" the bricks with soapstone in a steel stove, would to risk damaging the interior of the stove because the soapstone didnt reflect the heat back into the firebox?  If thats the case, you would need to add a layer of soapstone over the firebrick, cutting your firebox capacity down some.

Just some ideas, not looking to get slammed or accused again


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## Fsappo (Dec 30, 2009)

Marty S said:
			
		

> Marty
> PS:  You'd be surprised where my hands have been.



Now I just think your flirting with me.  
So I think I have a half dozen of those soapstone bricks someplace.  I can place them along one side of a steel stove in my showroom (inside of course) replacing the firebrick.  I'll burn a 4 log fire which should be on the decline after a few hours.  Then, I'll take a heat reading on both sides (outside) of the stove after the fire has been just about out for an hour or so.  If my theory is correct, the side with the soapstone should be radiating heat into the room longer than the firebrick side.  Am I missing something with this idea?


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## cycloxer (Dec 30, 2009)

Firebrick is intended to be used in high heat applications to protect the steel of the stove. Soapstone is intended to be used as a heat sink to retain heat for long periods of time. You don't really want to replace one w/ the other. I have seen soapstone inside of a steel stove. Hearthstone does this on their Craftsbury. They use 4 soapstone blocks in the firebox to increase the thermal mass of the stove, but this is a very small stove to begin with and that is how it was designed.

Oh, and I am an ME.


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## karri0n (Dec 30, 2009)

It's not a matter of damaging the stove; you just end up with lower temps because the heat isn't being reflected back into the heart of the fire, is being absorbed by the higher thermal mass, and is conducted outward by the higher conductivity of the stones. The increased thermal mass, heat conductivity, and lack of reflective radiation could very well prevent the stove from reaching secondary combustion temps. 


What I think would be a great experiment would be to add some refractory lining to a hearthstone stove, or replace the interior soapstone bricks with lightweight pumice firebrick. I'm quite certain this would raise temps and efficiency inside the stove, but it might make it a bit too hot for those fragile hearthstone panels.


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## Fsappo (Dec 30, 2009)

cycloxer said:
			
		

> Firebrick is intended to be used in high heat applications to protect the steel of the stove. Soapstone is intended to be used as a heat sink to retain heat for long periods of time. You don't really want to replace one w/ the other. I have seen soapstone inside of a steel stove. Hearthstone does this on their Craftsbury. They use 4 soapstone blocks in the firebox to increase the thermal mass of the stove, but this is a very small stove to begin with and that is how it was designed.
> 
> Oh, and I am an ME.



Isnt the Craftsbury cast iron?  I never sold one of those, but I assumed it was


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## Fsappo (Dec 30, 2009)

karri0n said:
			
		

> It's not a matter of damaging the stove; you just end up with lower temps because the heat isn't being reflected back into the heart of the fire, is being absorbed by the higher thermal mass, and is conducted outward by the higher conductivity of the stones. The increased thermal mass, heat conductivity, and lack of reflective radiation could very well prevent the stove from reaching secondary combustion temps.
> 
> 
> What I think would be a great experiment would be to add some refractory lining to a hearthstone stove, or replace the interior soapstone bricks with lightweight pumice firebrick. I'm quite certain this would raise temps and efficiency inside the stove, but it might make it a bit too hot for those fragile hearthstone panels.



In 25 years of selling Hearthstone I have yet to (knocking on wood) replace a damaged soapstone.  I know it has happened to others in the past to other folks.  I just never considered them to be "fragile"


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## karri0n (Dec 30, 2009)

I've seen several threads on here regarding cracked stones on hearthstone stoves. I'm not bashing them, as I know they make a good product, but I haven't seen anything about a cracked stone on a woodstock stove.


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## LLigetfa (Dec 30, 2009)

I don't think replacing firebrick with soapstone would result in any sort of nuclear meltdown of the stove per se, but it could change the required clearance to combustibles (CTC) enough to create a fire hazard.  If CTC is not an issue, it could still move the sweet spot of the stove to where it affects the EPA rating and efficiency.

That said, with my stove I time the removal of ashes with the outdoor temps and subsequent need for heat.  With fewer ashes in the stove, I get a lot more heat out of it.  I would not dare change out the firebrick for fear of changing the CTC as my stove is a zero clearance and as such has no possible additional margin of safety.  I run my blower when the stove is putting out max heat but in a power failure without the blower, it is pushing the CTC to the max.

Any major modification to a stove that affects the transfer of heat one way or the other could create a hazard.  If you kept more heat in by lining the top/sides with soapstone it could raise flue temps.  If you wick away heat by removing insulation, it can cause a CTC hazard.  I'm pretty sure both the stove manufacturer and your insurance company would take a dim view of such mods.


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## cycloxer (Dec 30, 2009)

Franks said:
			
		

> Isnt the Craftsbury cast iron?  I never sold one of those, but I assumed it was



Yeah it is a full cast iron stove. Inside the firebox there are 4 soapstone bricks (two on the floor and two on back wall) roughly 4"x6"x1" that they use to increase the thermal mass of the stove. Interesting concept.

I don't see any problem with modding a stove if there is something to gain, but I don't think there is in this case.


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## LLigetfa (Dec 30, 2009)

Here is a reason why NOT to mess with the CTC of a stove.  In the following example the install is not to code and one has to wonder why the place hasn't burned to the ground.  It looks like an insert designed to sit on a hearth, not on a thin veneer of slate and backer board.  It could well be the insulating property of the firebrick that is keeping the owner from being nominated for a Darwin award.

http://i628.photobucket.com/albums/uu5/bringitbig/9fd8c24d.jpg


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## Fsappo (Dec 30, 2009)

Huh, the front of that stove looks like an old Defiant.  I wonder what that critter is?


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## Martin Strand III (Dec 30, 2009)

"Soapstone is a unique refractory and masonry material.  Compared to a pound of concrete, a pound of soapstone can store approximately 20% more heat.  Its main distinctive thermal property is that it has about 4X the conductivity of concrete or about 6X the conductivity of soft clay brick.  Another way of saying this is that its R value is 1/4 that of concrete.  It is somewhat similar to metal in this respect.  This means that a soapstone heater of equivalent mass will heat up faster on the outside surface and reach a higher surface temperature, due to the high conductivity.  On the other hand, the higher rate of heat transfer to the room also means that *it cools down faster than other masonry materials.*  Understanding the thermal properties of soapstone..... we use soapstone heat transfer plates in castable refractory bakeoven floors to even out cool spots.  A nice feature of soapstone is that it can be carved quite easily."

----- Part of a presentation at All Fuels Expo 96 by Norbert Senf, Burlington Vermont, February 2, 1996

I'll put my marbles with Norbert on this soapstone thing.

Aye,
Marty


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## Fsappo (Dec 31, 2009)

Nope, never trust a guy named Norbert.  I rest my case.

So now, im stuck with the notion that if I heat up a red brick, a firebrick, a pumice brick and a soapstone brick all using the same amount of heat energy the soapstone will cool off quicker?   I'll try it, but it may have to wait until after the busy season for me to do it right.  As far as equal energy, I could just place s sterno can under each one.  That should do.  Wait for the cans to run out of gel, come back in an hour and shoot them with a heat gun?

So Bert here is saying a Soapstone stove will heat up and cool down faster than a steel stove?  This is worse than finding out Santa wasnt real..and that ruined my 23rd christmas


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## cycloxer (Dec 31, 2009)

*Question for Norbert:* Then why are companies like Woodstock and Hearthstone using soapstone as a heatsink in their stoves? I think he is only comparing soapstone to other masonry materials and not metals.


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## karri0n (Dec 31, 2009)

Franks said:
			
		

> So Bert here is saying a Soapstone stove will heat up and cool down faster than a steel stove?  This is worse than finding out Santa wasnt real..and that ruined my 23rd christmas



No, he's saying it will heat up and cool down faster than a brick or concrete masonry heater.

You also need to take into account the mass and the conductivity of these items. A pumice brick of equal mass to a soapstone brick will be much larger, and its relative lack of thermal conductivity means it will be pretty unlikey to heat up much at all in your "can of sterno" experiment. It's likely the top of that huge piece of pumice will stay cool the whole time. The heat from the flame will be refracting and going around the pumice stone rather than into it. An oven is a much more controllable heat source for the experiment. To establish a good baseline, You would need to measure the temp of each one before heating, directly after heating, and ten minutes later. By an hour it's most likely that they will all have cooled to room temp.  Even this experiment could be a bit touchy in regards to the pumice due to its porosity. For frame of reference in regards to the pumice, picture trying to test how long a piece of fiberglass insulation holds heat. It's just not easy to heat up in the first place, and as soon as air touches it, it goes back down. The low mass, light color, high refractory value, and lack of conductivity of pumice are what make it so suitable as a firebox insulator.


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## Fsappo (Dec 31, 2009)

I guess I'm just not smart enough to debate this.  I will revert to my ole "The Mansfield in my showroom stays hotter longer than the steel stoves" Theory.  I will though try the idea of lining one side of a steel stove with soapstone instead of firebrick and compare skin temps.  Any holes in that type of experiment?


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## karri0n (Dec 31, 2009)

Franks said:
			
		

> I guess I'm just not smart enough to debate this.  I will revert to my ole "The Mansfield in my showroom stays hotter longer than the steel stoves" Theory.  I will though try the idea of lining one side of a steel stove with soapstone instead of firebrick and compare skin temps.  Any holes in that type of experiment?



Sure, try it.

I'd also like to see how different the temp of the stove is during the burn. I don't know if only doing the one side will affect the overall characteristics too much,but it would be cool to see. I think you should do one burn with the firebox fully line with firebrick, one with it fully lined with soapstone, and one with the one-side thing.


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## Fsappo (Dec 31, 2009)

If I do 2 burns, I guess I'll have to weigh the wood each time to make sure we're using the same input.  I just dont have enough soapstone in stock to fully line a stove.  I'll keep pestering myself about it.


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## Martin Strand III (Dec 31, 2009)

Yu'all:

In order to compare apples to apples, the masonry samples need to be the same MASS and roughly the same shape.  Size will differ; soapstone being DENSER will be smaller than fire brick, clay brick, natural rock, etc.  No need to worry about the physics.

For a heat source, consider putting the samples in an oven on the regular oven metal rack at a constant temperature (say 400* F), apart but on the same shelf, for several hours to make sure all is heated thoroughly.  After 2 hours, open the oven door, record the temperature of the samples (ideally without touching them) then and then hourly leaving the door oven open, no obvious drafts, etc..  Record results and report back.  Voila!  Oh, yes.  No cheating to favor your thesis.

Aye,
Marty


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## Martin Strand III (Dec 31, 2009)

cycloxer said:
			
		

> *Question for Norbert:* Then why are companies like Woodstock and Hearthstone using soapstone as a heatsink in their stoves? I think he is only comparing soapstone to other masonry materials and not metals.



Norbert told me  ;-) adding masonry to a metal stove improves (1) combustion efficiency in the firebox (insulating, reflecting heat back into the firebox to get a higher burn temperature) and (2) moderates (lowers) the heat transfer efficiency (metal stoves typically have lower combustion efficiency and high heat transfer efficiency) of the stove.

Aye,
Marty
PS:  The ''ideal"  :bug: wood burning stove/heater has high combustion efficiency along with moderate heat transfer efficiency.


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## Fsappo (Dec 31, 2009)

So do I determine the mass by weight?  a 5lb soapstone (firebrick sized is what I have) and find a chunk of typical firebrick that weighs the same?


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## Martin Strand III (Dec 31, 2009)

Franks said:
			
		

> So do I determine the mass by weight?  a 5lb soapstone (firebrick sized is what I have) and find a chunk of typical firebrick that weighs the same?



By jove, I think you've got it!

Aye,
Marty
PS 1:  Which weighs more, a pound of sand or a pound of feathers?
PS 2:  In order for a test to be valid (by "the scientific method"), it must be reproducible, in every detail, by others who will get the same results.


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## Fsappo (Dec 31, 2009)

That should be easy enough using the oven idea.  I just need to go weigh my soapstone brick and find an firebrick the same weight and relative shape.  A pound of sand weighs more than a pound of feathers, silly..and a pound of gold even more.


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## Martin Strand III (Dec 31, 2009)

Franks said:
			
		

> (SNIP) A pound of sand weighs more than a pound of feathers, silly..and a pound of gold even more.



Using a pure radiant energy source, which will heat up faster (therefore cool down faster)  - the sand, feathers or gold?  And why?

Aye,
Marty


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## Fsappo (Dec 31, 2009)

The surface temp or the core temp when heating up?  The side facing the radiant heat source if it is surface temp?


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## Martin Strand III (Jan 1, 2010)

Franks said:
			
		

> The surface temp or the core temp when heating up?  The side facing the radiant heat source if it is surface temp?



Not to worry.  Take a surface temperature of each sample at reasonable time intervals.  Radiant heat physics (sic) will not penalize you for taking a surface temperature which will be representative of the entire sample after allowing enough time for sample equilibration; i.e., you'll be close for this experiment - you'll need better experiments to inhabit Mars, find alternate fuel sources, etc...

Aye,
Marty


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## Corriewf (Jan 8, 2010)

Any update with this experiment Franks? A buddy of mine was thinking about this as well.


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## Fsappo (Jan 8, 2010)

Not even close.  It is go time at the fireplace shop with the cold weather here.  I did stash a soapstone brick aside for it.  I just need to weigh it and find some other masonry type materials of the same weight.  I was going to try standard firebrick and pumice, just for kicks.  I could always stack brick together to get the same weight, but would the air space in between each brick cause any issues with heat transfer?


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## karri0n (Jan 8, 2010)

Considering the original question was simnply replacing the firebrick, as opposed to testhing thermal properties of the stone, I think using the same dimensions rather than the same weight for the in-stove test makes more sense. As far as the test of how the different materials hold temp, this is where you will need stones of the same *mass*


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## Martin Strand III (Jan 8, 2010)

Franks said:
			
		

> (SNIP) would the air space in between each brick cause any issues with heat transfer?



It does the same that air space between 2 panes of glass or air space between feathers of a duck: insulate; retards heat transfer.

Aye,
Marty


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## Fsappo (Jan 8, 2010)

Well, we already established duck feathers weigh the same as brick, so we're beyond that.  I was wondering if the air space, being so small (brick against brick) if it would insulate to the point of changing the goal of the test.


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## oconnor (Jan 8, 2010)

LLigetfa said:
			
		

> I don't think replacing firebrick with soapstone would result in any sort of nuclear meltdown of the stove per se, but it could change the required clearance to combustibles (CTC) enough to create a fire hazard.  If CTC is not an issue, it could still move the sweet spot of the stove to where it affects the EPA rating and efficiency.
> 
> That said, with my stove I time the removal of ashes with the outdoor temps and subsequent need for heat.  With fewer ashes in the stove, I get a lot more heat out of it.  I would not dare change out the firebrick for fear of changing the CTC as my stove is a zero clearance and as such has no possible additional margin of safety.  I run my blower when the stove is putting out max heat but in a power failure without the blower, it is pushing the CTC to the max.
> 
> Any major modification to a stove that affects the transfer of heat one way or the other could create a hazard.  If you kept more heat in by lining the top/sides with soapstone it could raise flue temps.  If you wick away heat by removing insulation, it can cause a CTC hazard.  I'm pretty sure both the stove manufacturer and your insurance company would take a dim view of such mods.



+1.  For example, in an insert stove, (like the OP has) you want the heat to reflect forward into the room vice radiate rearward into the masonary behind the stove.  Also, in a stove with small rear CTC, it would totally invalidate the clearances, as you would have more heat back there than before.  Could also take out the blower as a result of increased operating temps.

Experiment aside, these are the relevant points for the original post IMHO.


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## Martin Strand III (Jan 8, 2010)

Franks said:
			
		

> Well, we already established duck feathers weigh the same as brick, so we're beyond that.  I was wondering if the air space, being so small (brick against brick) if it would insulate to the point of changing the goal of the test.



For an "apples to apples" test - ideally, each specimen should be the same:
1.  1 piece each, same weight, no holes or 'spaces'
2.  2 pieces each, same weight, equal 'spaces' between

 :exclaim: Why not use 1/2 piece (or so) of your firebrick and whittle down a red brick (or other) to the same weight?

Aye,
Marty


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## Fsappo (Jan 8, 2010)

I dont wanna waste a soapstone brick nor do I have time right now to whittle!  I may take the advice though.  This may need to wait till the spring


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## Martin Strand III (Jan 8, 2010)

Franks said:
			
		

> I dont wanna waste a soapstone brick nor do I have time right now to whittle!  I may take the advice though.  This may need to wait till the spring



Why not apply for a Grant?  Or, rummage around a brick yard?

Aye,
Marty


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## Fsappo (Jan 8, 2010)

Because I work 60 hours a week, have a new baby at home and NFL Football to watch.  A man must prioritize.  The grant idea is an interesting one.  Imagine getting a grant to put bricks in an oven and shoot em with a heat gun?  Now that I think of it, scientists get grants to study stranger things.


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## Martin Strand III (Jan 8, 2010)

Franks said:
			
		

> Because I work 60 hours a week, have a new baby at home and NFL Football to watch.  A man must prioritize.  The grant idea is an interesting one.  Imagine getting a grant to put bricks in an oven and shoot em with a heat gun?  Now that I think of it, scientists get grants to study stranger things.



With over 1400 posts (on just this forum...), you have the time.

The scientific world is anxious for data.

Aye,
Marty


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## Fsappo (Jan 8, 2010)

Typing a 20 second blurb between customers is different than an experiment.  But I'll go see what I can come up with.


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## karri0n (Jan 8, 2010)

For a true experiment in the spirits of the original post, you need to use bricks of the same size, not the same mass. I'm also having trouble figuring how you're going to manage to fit the same *mass* of pumice into the stove without lowering the fuel capacity significantly.


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## Corriewf (Jan 8, 2010)

Franks said:
			
		

> Not even close.  It is go time at the fireplace shop with the cold weather here.  I did stash a soapstone brick aside for it.  I just need to weigh it and find some other masonry type materials of the same weight.  I was going to try standard firebrick and pumice, just for kicks.  I could always stack brick together to get the same weight, but would the air space in between each brick cause any issues with heat transfer?



I would stick with your original experiment because it is more practical. The density of soapstone is higher so you would need more firebrick to compare however you can't double the firebrick in a stove. Do the one for one deal and try soapstone on half a side and firebrick on the other. Just my thought, as my friend would be replacing 1 firebrick for 1 soapstone like the OP.


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## Corriewf (Jan 8, 2010)

Franks said:
			
		

> Because I work 60 hours a week, have a new baby at home and NFL Football to watch.  A man must prioritize.  The grant idea is an interesting one.  Imagine getting a grant to put bricks in an oven and shoot em with a heat gun?  Now that I think of it, scientists get grants to study stranger things.



You're the man Franks...You can watch that football next year. I am sure the Mrs will understand you not being there and that baby won't even remember you not being there. It's fine man.. You're the go to guy RIGHT now. This experiment could shake the very foundation of the wood stove world...


In all seriousness, if you found out that soapstone can replace firebrick and be more efficient, it would be a great discovery. Dealers would start selling a lot more soapstone to replace firebrick and you could even start offering upgrade packages to soapstone.


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## Fsappo (Jan 8, 2010)

Yeah, I'm wondering if I should scrap the oven idea, contact Hearthstone and see if they want to send me a box of soapstone bricks for me to mess with in my showroom.  I would love to completly line a steel stove with soapstone and see what happens.  Video tape the seconday combustion, etc.


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## SolaGracia (Jan 8, 2010)

I must, as the OP, demand at least a small royalty for the original idea!  I'd say 15% is reasonable---


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## Corriewf (Jan 8, 2010)

Franks said:
			
		

> Yeah, I'm wondering if I should scrap the oven idea, contact Hearthstone and see if they want to send me a box of soapstone bricks for me to mess with in my showroom.  I would love to completly line a steel stove with soapstone and see what happens.  Video tape the seconday combustion, etc.



Yeah, no point in doing the other test with equal mass. I can only fit one soapstone or one firebrick to line my vogelzang. You get good results and can prove it, I may order a box of soapstone from you myself. The problem with my steel stove is that it doesn't hold the temps very long. Maybe it may heat up slightly faster than iron, BUT I only get a few (maybe two) hours of good heat output. I would sacrifice a little longer heat up time and even a little on the temp if I could hold a steady temp for say double the time. 

You test it, you get good results, you get a steady supply of soapstone that you can cut to order, you will have orders out the ears.

Heck, I would even let you date my sister....If I had one.


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## Fsappo (Jan 9, 2010)

Pics!

I'm not looking to sell Soapstone because of this.  I just have some replacement bricks I got from Hearthstone for a Clydesdale.  I'm doing this to see if what I have been led to believe for 20+ years is accurate, and if so, what kind of a difference there is.

Now about this sister..it doesnt really need to be your real sister...or real at all


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## Martin Strand III (Jan 9, 2010)

Franks said:
			
		

> Typing a 20 second blurb between customers is different than an experiment.  But I'll go see what I can come up with.



Attaa...boy!  No sniveling.

Aye,
Marty


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## Martin Strand III (Jan 9, 2010)

Franks said:
			
		

> (SNIP) I'm doing this to see if what I have been led to believe for 20+ years is accurate, and if so, what kind of a difference there is.(SNIP)



FYI:  To be 'really' accurate, the Scientific Method requires starting with a "null hypothesis"; i.e., challenging what you think to be true in the form of a 'reverse' statement, such as:

Example:  Franks Null Hypothesis:  "Firebrick holds heat longer than soapstone."  

Now, design the experiment, if you can, to 'disprove' your null hypothesis...

Please let us know your Null Hypothesis before getting into this so far you invalidate the entire experiment by omitting this essential first step.  Adding it, or changing it, later just doesn't cut it...  There's just too much schlep out there already.

Oh.  One more thing:  there's a difference between "working 60 hours a week" and "being at work 60 hours a week".  Believe me.  I know.

Aye,
Marty
Grandma used to say, "By Golly, one day they'll put a man on the moon!"


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## Fsappo (Jan 9, 2010)

Your nerdiness almost has me talked out of doing this.  I think I may just keep telling folks soapstone holds heat longer than firebrick and let someone else with a larger vocabulary do the testing.  Your welcome to spend 6 days with me one week, Marty, and see what it consists of during the cold months.


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## Martin Strand III (Jan 9, 2010)

Franks said:
			
		

> Your nerdiness almost has me talked out of doing this.  I think I may just keep telling folks soapstone holds heat longer than firebrick and let someone else with a larger vocabulary do the testing.  Your welcome to spend 6 days with me one week, Marty, and see what it consists of during the cold months.



I wouldn't go into a project less than 100% enthused.  Maybe it's best for all if you do drop this apparent challenge which might be picked up by some one with more 'bling'.

Aye,
Marty
Grandma used to say: "Any job worth doing is worth doing well."


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## Fsappo (Jan 9, 2010)

Yeah, but I may revisit it when we slow down in the spring/early summer.  Excellent use of the term "bling" by the way


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## Corriewf (Jan 10, 2010)

Franks said:
			
		

> Pics!
> 
> I'm not looking to sell Soapstone because of this.  I just have some replacement bricks I got from Hearthstone for a Clydesdale.  I'm doing this to see if what I have been led to believe for 20+ years is accurate, and if so, what kind of a difference there is.
> 
> Now about this sister..it doesnt really need to be your real sister...or real at all



SURE! It might blow up and retain hot air for a while, but all yours. Show you what happened to a buddy of mine when he asked for pics of women's feet while I was on vacation. 

http://www.youtube.com/watch?v=G--7yJwYqYQ

@ Marty, if you have nothing else to do but act like an ass, find somewhere else to do it please. The OP and myself would really like if you would quit belittling Franks with discontent. Do your own experiment and write a thesis on it. We are talking about wood stoves and replacing one brick with one soapstone.


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## thinkxingu (Jan 10, 2010)

That was a terrible use of the word 'bling.'  Bling has always been used to describe or identify flashy jewelry, automobile paraphernalia, or personal 'accouterments', usually in connection to pop-culture, as a means of indicating status.  The etymology of the word indicates its origin to be connected to the perceived sound a diamond makes in the sun or otherwise bright light source.  Its development was somewhat facetious and implied the simplicity of attraction to 'shiny objects' but has come to represent something 'pretty' or 'desirable.'  It, however, is never used by people to indicate wealth or financial resources.  In fact, it is often contrary to that as many poor, urban youngsters will wear 'bling' in the form of fake diamond studs.

Regardless, I think it would be simple and effective enough to throw some firebricks and soapstone bricks in a stove, heat it to a given temp, and time how long it comes down to another given temp.  If in the end it's only a half hour or so, than it doesn't really matter anyway.  If we're talking an hour or more, perhaps there should be further inquiry.

S


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## SolaGracia (Jan 10, 2010)

The whole premise behind the original posting was that my steel insert is horrible at retaining heat.  It takes a long time to get to temp, and then when it gets there, it does not stay very long.  It is especially bad at retaining heat when the blower is on high.  I will have gone through about 1.5 cord of wood in just under a month here if the pace keeps up.  Considering I have no reserve, this is slightly distressing.  And overnight burns?  Forget it---I am lucky to get 3 hours of useful heat out of one load.  These companies that claim 8 or 10 hour burns on a single load should be sued for misrepresentation.

I am going to take some time to monitor the heating cycle and plot it out on a spreadsheet to post here to see if I am just crazy--and to try and figure out if it is really the insert, or the wood, or a combination of both + user error.


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## thinkxingu (Jan 10, 2010)

Sola, have you posted a thread about your situation?  Specifically, about the wood you're using, temps you're using it in, size of the room, load cycle, etc?  Our steel stove definitely heats up and cools down quickly, but we can get at least 6 hours of meaningful heat from it, and it's got a small firebox (1.5 cu. ft?).

S


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