Firebricks, differences from one to the next ?

[KsWoodsMan]

I'm considering building a wood fired heater for the shop. I intend to discuss the design during and after construction. Right now, sourcing firebricks are my main concern on this.

Are there many differences in firebrick used for insulating inside a wood stove? Are there any that are better than others , temperature wise ? If so , is the a good source for these that's going to be reasonably priced ?

What I have found so far has been good for 1800 degrees to 2200 degrees. They seem to be physically similar. They all seem to have same color , weight and texture. I know for ceramics the temp they are good for depends on the initial firing temp.

 

[dingeryote]

Good question and I'm all ears too!!!

It's time to re-do mine, and there is no reason not to know a little more about the humble little bricks.
Got a couple dozen Vogelzang bricks that are definately not the same as Quadrafire OEM...so ther is a difference.

Heck, if anyone has tricks or tips on cutting the things it would be cool as well.
(No names, but somebody here definately flunked "Stonemasonry 101")


Stay safe!
Dingeryote

 

[KsWoodsMan]

Dingeryote, as far as cutting them I worked around a guy scoring/cutting them on the table saw. He turned a carbide tipped blade around and ran it backwards. Awful noises and dusty but it got the job done.

 

[Steve NW WI]

CrappieKeith has posted in some other threads about the different grades of firebrick, but I can't find it right now. Hopefully he will be along in the morning with some answers for you.

I've had limited success (read good enough for me, but not perfect) with scoring with a sawzall and then breaking with a chisel. I've lost a couple bricks before getting a good one, seems like you need a 1/4 or so of the brick thickness score to be reliable. Next time I might see what the chop saw will do to brick.

 

[dingeryote]

LOL!!!!

Carbide blade run backwards to score....gotta try that.
Tile saw does ok, but is SLOOOOOOWW.

From there is the part I'm muffing up.LOL!!!

Might try the carbide saw blade backwards and score both sides deeper.
Vogelzang sells 'em by the half dozen for a reason.:hmm3grin2orange:


Stay safe!
Dingeryote

 

[deerlakejens]

I cut a lot of pavers with a diamond blade cooled down with a low volume water hose. The dust with an abrasive blade is overpowering. A tile saw with a diamond blade would also do a very clean job. I can't believe it would be too hard to find a tile shop who would cut a few bricks for cheap.

 

[HILLBILLYREDNEC]

The thicker the brick the better insulation value. The other way to score a brick is masonry wheel on a circular saw and a shop vac.

 

[Guido Salvage]

The thicker the brick the better insulation value.

Not always true. For example a common brick (4" solid") has almost double the R value of a face brick (4" with holes). Material density plays a crucial role in determining the insulating value of a material as the R value is a measurement of of the resistance to heat flow across a material. To illustrate this point, a solid 4" common brick has a higher R value than a solid 4" cinder block.

The other way to score a brick is masonry wheel on a circular saw and a shop vac.

Again not accurate. A wheel is typically a term used to describe an attachment for a grinder or a cutoff tool whereas a blade is used on a saw. For that reason most wheels are a smaller diameter than a saw blade and also may have a larger arbor opening than would be used on a circular saw. Specialized blades are available for cutting a variety of materials including industrial diamond blades for masonry products.

Not sure how a shop vac is used to "score a brick", but the standard means of cutting bricks is with a wet saw. If you have ever done any masonry work you know the amount of dust that is created. Running a low volume of water over the blade and material being cut reduces the dust and helps to cool the blade.

The dust is the reason the most used target (chop) saws have such poor compression and trashed P&Cs.

Truth o Meter says....

 

[dingeryote]

I cut a lot of pavers with a diamond blade cooled down with a low volume water hose. The dust with an abrasive blade is overpowering. A tile saw with a diamond blade would also do a very clean job. I can't believe it would be too hard to find a tile shop who would cut a few bricks for cheap.

Thanks,

Got a tile saw, and probably havn't been scoring deep enough before going to flint knapping on the brick.LOL!

Stay safe!
Dingeryote

 

[Justsaws]

I'm considering building a wood fired heater for the shop. I intend to discuss the design during and after construction. Right now, sourcing firebricks are my main concern on this.

Are there many differences in firebrick used for insulating inside a wood stove? Are there any that are better than others , temperature wise ? If so , is the a good source for these that's going to be reasonably priced ?

What I have found so far has been good for 1800 degrees to 2200 degrees. They seem to be physically similar. They all seem to have same color , weight and texture. I know for ceramics the temp they are good for depends on the initial firing temp.

There are lots of different types of firebrick. See if you can source a local refractory supply house and take a look at them, for low temp/hard type bricks used in fireplaces and such any building supply that supplies typical red brick and concrete blocks should be able to get them. Get the manufacturers spec sheets.

Buying small lots, less than a pallet, tends to result in "retail +" pricing.

Vulcan Refractories is the only brand that I remember offhand. Thermo???? got a lot of my money years ago. If you want to save space in the design you might be better of to face the burn area in a hard brick/panel and use soft or sheeting behind.

I am set to clean that area of the barn today and will see if any of the stickers are still readable.

Beware of the dust in refractory materials, it is not the same as tile and red brick.

 

[Coldfront]

There is some good info on this website Brick Oven Design | Choose the Right Brick Oven Brick

And here is another one
http://www.traditionaloven.com/articles/84/firebricks-heavy-dense-fire-clay-bricks

 

[s219]

If you have an angle grinder, just get a masonry wheel (they make cutter and grinder wheels for masonry). With a cutter wheel, you can score or cut pretty much anything nice and accurately. I use it whenever I have to do any sort of precision cuts in cinder blocks. For soft stuff like that, I cut all the way through. For harder stuff, I'd score then hit with a chisel.

 

[CrappieKeith]

There are 3 duties in brick on the market.
Light ,medium and heavy. I do know heavy duty bricks are rated at like 3200 degrees and are the most dense of all the fire brick out there. Pizza ovens for example use the heavy duty like we use.

We have 2 sizes in the full 2" thick brick...9x6x2 & 12x6x2 inchers.

 

[Coldfront]

I read on one of those links there are also insulating fire brick, that you may want to use on the back side to insulate the heat going towards a close wall.

 

[Fyrebug]

As Keith mentioned there are a few different grade. Stay away from the 'pumice' brick. You can tell them apart since they are light in weight, typically grey and lumpy surface. They are cheap but dont last very long.

Better to go with 'refractory' bricks. They come in a few standard sizes. Once you have the inside dimension of your chamber let us know and we'll provide you with sources where you can get some.

 

[KsWoodsMan]

Thanks guys there was some useful information presented earlier.

I should have been a little more clear. I will be using them for insulating the primary combustion chamber of the appliance. Thermal mass in the firebrick isn't what I'm going after. Some very crude initial tests have shown the temperatures generated will disintegrate cinderblocks. I'm thinking the temps easily reached 1400+ to do this. Since it is natural draft, I'm not expecting internal temps over 3000 and only in spots. So, I have my doubts about lesser bricks standing up to my trial by fire method of testng.

i hadn't thought about the different kinds of dusts coming off refractory material. But the warning is well heeded. It looks like the cutting will be done with a chisel or wet saw. The last thing I want to breath is pearlite. IIRC, pearlite has a higher than expected content of asbestos.

One thought that came to me was the use of refractory cement and casting the insulation to fit the inside of the burn chamber. Curing the casting could be done with forced air and a couple Casting it as opposed to using approx 35 bricks to line it. This will probably save me a considerable amount of time. As planned, each of the 4.5"x9" bricks will require shaving 12.5° off each of the long edges. The burn chamber will be round and stand upright with a height of approx 22".

I'm open to suggestions for other possibilities than firebrick. Thanks again.

 

[ray benson]

The thicker the brick the better insulation value. The other way to score a brick is masonry wheel on a circular saw and a shop vac.

I have used a skil 77 worm drive saw with a 7" Masonry/Tile cutting abrasive blade - scoring both sides of the brick and breaking it along the score. Have to do it outside as it's pretty dusty.

 

[HILLBILLYREDNEC]

Ks a poured liner would need reinforcement wire. The poured would be a good option for getting enough thickness in the critical areas. Got some pictures of the rough unit? Cement block with a poured in place face would work as well.

 

[PA Plumber]

I've got a PE Summit that has some cracked brick...

Maybe it was mentioned, does one need to switch out all the brick after so long? Or, just replace cracked ones?

 

[KsWoodsMan]

Ks a poured liner would need reinforcement wire. The poured would be a good option for getting enough thickness in the critical areas. Got some pictures of the rough unit? Cement block with a poured in place face would work as well.

Reinforcement wire shouldn't be a problem. I don't expect that to complicate the assembly, much.

Follow this link to Mother Earth News for what it started out as.

For me, the oil burner just didn't turn out as hoped. It sure makes heat and didn't take much to get to burn 'clean'. A barometric damper should have been designed with it too. But that's a different story for a different thread on another forum. I got to wondering what was in the coke I kept cleaning off the burn pot. I decided not to continue using it because of this.

As this progresses and time allows, I'll get something posted on here with fairly detailed pictures of assembly and use as well as theory of operation.