regular and light weight firebrick differences

[Huntindog1]

I heard that there are some new wood smokers being designed that they replace firebricks with 3/4" plate steel as it has a higher density and higher mass.
Behind the 3/4" plate steel they are putting like 1" to 2" of Ceramic Koawool to cut the conduction down and provide the insulation needed to keep things hot. Would take longer to heat up like a soapstone.

 

[precaud]

Yup. Good example. Not unlike using cast iron liners with kaowool backing aka Jotul. Keeps this "hotter, longer" but the stove never gets as hot as a proper insulating firebrick would allow it to. High firebox mass is like having a speed governor on a motor.

 

[Huntindog1]

Precuad, I see your rationale as if we can some how store the heat to radiate later when the stove flames out then we have heated our house better.

My idea maybe flawed but I only was thinking about extracting more btu's from using a hotter firebox. Especially at my stoves lowest setting. As If I can run my stove at a lower setting I get a longer burn. Again like i hoped at that lower setting and higher firebox temps I was hoping of getting more heat from the extra amount of smoke gases being burnt.due to a higher firebox temp.

But there is many ways to skin a cat, I like Precauds idea of once your wood gets to the coal stage to completely shut down all air flow in the stove and the coals will radiate heat over a much longer time period as it said that 20% of your heat goes up the flue and is wasted , well if you have the ability to shut off your secondary air and all of your primary airs then there is no air flow at all flushing the 20% of the heat up the flue. I should also state that once your at the coal stage creosote is no longer an issue as all of that stuff has been burnt out of the wood.

 

[precaud]

I only was thinking about extracting more btu's from using a hotter firebox. Especially at my stoves lowest setting. As If I can run my stove at a lower setting I get a longer burn. Again like i hoped at that lower setting and higher firebox temps I was hoping of getting more heat from the extra amount of smoke gases being burnt.due to a higher firebox temp.

There's no doubt that firebox insulation allows for more stable burns at lower rates. An insulated chimney helps there too.

But there is many ways to skin a cat, I like Precauds idea of once your wood gets to the coal stage to completely shut down all air flow in the stove and the coals will radiate heat over a much longer time period as it said that 20% of your heat goes up the flue and is wasted , well if you have the ability to shut off your secondary air and all of your primary airs then there is no air flow at all flushing the 20% of the heat up the flue. I should also state that once your at the coal stage creosote is no longer an issue as all of that stuff has been burnt out of the wood.

I like the all-of-the-above strategy!

 

[raybonz]

Anyone tried these? Just noticed a couple cracked firebrick in the back of the stove this morning when the fire lit.. I don't know the density of these bricks but the price is right!

http://www.tractorsupply.com/united-states-stove-single-firebrick-9-in--3112783

Ray

 

[madison]

The ones I picked up at tractor supply, last yr, were at least 2 to three times heavier. I have not used them yet, but have flipped some of the ones that have deteriorated.... none have cracked, just severely eaten away.

 

[BrotherBart]

If the price is great you can bet that they are regular ceramic, not pumice, bricks.

 

[FyreBug]

The video is a sideline, not on topic. Lopi has a reputation of building tough stoves. Conventional firebrick is tougher. Lopi smartly is touting this as a feature, the same way SBI boasts the toughness of it's c-cast baffles. Good marketing but a bit off topic I think.

I think it's very much on point... If companies such as Lopi, SBI and others who have labs and the ability to measure material performances all day long do not see any performance advantages in using light weight bricks versus heavy duty bricks, it should tell you something... Especially in view of EPA tightening up their regulation for emissions and eventually efficiencies.

If any MFG could prove better efficiencies, burn time, clean burn etc... with different bricks, do you not think they would 1) publish and brag about it with some real numbers 2) make sure they would only use that material?

We test and sell fireboxes with either bricks. We reserve the heavy duty bricks for our furnaces and our upscale brands for all the reasons mentioned previously and so does some other MFG's.

 

[raybonz]

The ones I picked up at tractor supply, last yr, were at least 2 to three times heavier. I have not used them yet, but have flipped some of the ones that have deteriorated.... none have cracked, just severely eaten away.

I have a dumb question.. Do you have to remove the baffle to remove the bricks? The manual has no information about this..

Thanx,
Ray

 

[madison]

No

 

[velvetfoot]

My experience on the two quads I had led me to replace the pumice bricks with the heavier ones. Not sure what I have now on the Hampton, but hopefully they will hold up better. I believe I have an email somewhere from Quad, that said their bricks are good til half the thickness is worn away. Half! Geez.

 

[raybonz]

No

Care to share how to remove and replace the back firebrick? BTW your stove and hearth look great!

Thanx!

Ray

 

[precaud]

If any MFG could prove better efficiencies, burn time, clean burn etc... with different bricks, do you not think they would 1) publish and brag about it with some real numbers 2) make sure they would only use that material?

Actually, no I don't think they would. Not unless they could patent it and were prepared with the resources and legal staff to defend said patent world-wide. But choice of firebrick doesn't qualify. Better to just keep using it and not draw undue attention to it, like most manufacturers do...

 

[raybonz]

If the price is great you can bet that they are regular ceramic, not pumice, bricks.

Yes they are not pumice and much heavier and harder too.. I am going to use these in the back of the stove as that is where 2 broken bricks are located.. I'll save the one good one for a spare for the bottom or sides.. I see nothing conclusive for or against using either brick type but I do feel the pumice bricks would be better insulators and based on this I want them on the bottom of the firebox..

Ray

 

[madison]

Care to share how to remove and replace the back firebrick? BTW your stove and hearth look great!

Thanx!

Ray

Ray,

They slide and lift right out. Wait for stove to cool. Put on a pair of gloves. The cracked ones should be easy to remove, and will then allow the other vertical bricks to slide to either side to clear the retaining tabs.

And once you slide one of the bricks a bit to clear the retainer tab hanging off the baffle rails it will become obvious. Just note that all of the bricks are not the same size. Note all of this is for the T6, T5 may be slightly different, but the general design should be similar. Once you do it once, you will chuckle that you asked.

 

[Huntindog1]

If you want to keep using the insulative Pumice type bricks you can buy a product call ITC-100 that forge and brick oven operators already use.
This is a ceramic coating that increases the durability of the bricks. It is also said the ITC-100 reflects heat back into the box but thats a whole other can of worms. I used it for that purpose. I also coated my ceramic baffle boards to give them more durability.

http://digitalfire.com/4sight/education/refractory_coatings_offer_new_firing_possibilities_110.html

Here is a place to buy small quantities of ITC-100.

http://www.hightemptools.com/itcproducts.html

 

[Huntindog1]

Brick material and Thickness chart. You can look at this chart and see how the temps of the fire box are higher for Insulating firebrick and Alumina.

Higher the Alumina content the more heat radiation reflective it is. Reflecting the heat back into the fire box area. As the hot flue gases exit the stove heat is radiate out the front and top of the stove.

Mullite refractory: Mullite brick is about 72% alumina with 28% silica. These have
excellent volume stability and strength at high temperatures. They are highly suitable
for electric furnace roofs, blast furnaces and blast furnaces stoves, and the superstructure of glass tank furnaces.

 

[raybonz]

Ray,

They slide and lift right out. Wait for stove to cool. Put on a pair of gloves. The cracked ones should be easy to remove, and will then allow the other vertical bricks to slide to either side to clear the retaining tabs.

And once you slide one of the bricks a bit to clear the retainer tab hanging off the baffle rails it will become obvious. Just note that all of the bricks are not the same size. Note all of this is for the T6, T5 may be slightly different, but the general design should be similar. Once you do it once, you will chuckle that you asked.

Yup it was easy lol.. I did find that the TSC fire bricks are slightly wider and could not fit 2 side by side where I removed 2 side by side bricks so I moved the one good pumice brick beside a new ceramic fire brick. I will need to cut ~1/6" off the long side of one brick. Wish I still had the tile saw I borrowed when I did my hearth for this!

Ray

 

[raybonz]

Brick material and Thickness chart. You can look at this chart and see how the temps of the fire box are higher for Insulating firebrick and Alumina.

Higher the Alumina content the more heat radiation reflective it is. Reflecting the heat back into the fire box area. As the hot flue gases exit the stove heat is radiate out the front and top of the stove.

Mullite refractory: Mullite brick is about 72% alumina with 28% silica. These have
excellent volume stability and strength at high temperatures. They are highly suitable
for electric furnace roofs, blast furnaces and blast furnaces stoves, and the superstructure of glass tank furnaces.

Thanx for posting Hdog but for right now I will try it out as is. These new bricks are quick dense and heavy and much whiter so they may be better at reflecting heat. I will find out very soon and report what I see..

Ray

 

[raybonz]

Just fired up the stove 2 of the heavy firebricks and noticed nothing different..

Ray

 

[Greek2Me]

I thought I read someplace about a coating and it still working once it became dirty, Its called Super Therm.

Reflective Coating vs. Fiberglass vs. SUPERTHERM ®
Manufacturers in the past have marketed "reflective" coatings by making claims that they continuously repel heat, and have specific "R" values. The problem with such claims is that these coatings only reflect visual light or short wave radiation, and when they become dirty they stop working completely. Once these claims proved false, all similar coatings were put into the same category and deemed non-viable.
SUPERTHERM ® was designed and developed with the assistance of NASA, a fact that can be substantiated. The "ceramic compound" blends found to work the best, and are now used in SUPERTHERM ®, resulted from 18 years of testing and research. The difference between the technology of "reflective" coatings of the past and SUPERTHERM ® today, is outlined below.
SUPERTHERM ® has the ability to block all the different radiation waves. SUPERTHERM ® not only blocks these waves when first applied, but continues to block them after the coating becomes dirty, which happens to all coatings. The ceramics used in SUPERTHERM ® were chosen from over 3,200 compounds, which were studied and tested in order to prove that they would block the different radiation waves the most effectively, producing the following results:
1. SUPERTHERM ® blocks 99% of UV heat
2. SUPERTHERM ® blocks 92% of Visual Light (short wave) heat
3. SUPERTHERM ® blocks 99% of Infrared (long wave) heat
This results in an average of over 96% of heat load blocked!

_______________________________________________________________________________________________

Before you invest ANY money in this product, you should check out this article. It made my decision easy!

http://www.greenbuildingadvisor.com...lating-paint-salesman-tripped-his-own-product

Maranatha

Greek2Me

 

[begreen]

3 yr old thread. Closing.