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Artichoke 11-23-2008 09:24 AM

Refractory brick in a bag?
Hi all,

I have been looking around for a source of refractory bricks and luckily there is a manufacturer less than an hour away. It seems as if it is a company that has been manufacturing these materials since 1905 Clayburn Industries (terrible website). The must know something. I called and they said they manufactured bricks with approximately 50% alumina content and that people have used these bricks for building wood ovens. The over the phone estimate was about $4 CDN/brick. With the trajectory on the economy this should be half that price in a week ;-).

Would you consider this a high duty brick (~50% alumina) ? Do you think this is in the correct range for a pizza oven? I still do not have my head around the concept of having an "over performing" high duty brick. The price seems high to me but I have yet to see the quality of the actual product and little experience to compare.

Now here is the bane of modern life, choice. The representative suggested an alternative of using their casting mix in bags that has a similar alumina content. I would build a form and cast a dome or segments of a dome to build the oven. The theory would be that I would save a lot of time and money in trying to construct a brick dome. Has any one here taken this approach (other than the professional pre-fab oven manufacturers)?

I guess in the cast approach one sinters the dome in situ with a firing. Is this really the same thing as having a dome made of kiln fired bricks?

It seems that in the cast approach I am substituting learning brick laying with learning how to cast a dome without failure. One critical mistake and the whole dome is lost. I would worry more about the dome "flaking" in use with a cast dome?

Thoughts appreciated.

RTflorida 11-23-2008 09:43 PM

Re: Refractory brick in a bag?
I would say 50% alumina = "high duty". A local refractory dealer gave me these "ballpark" numbers:
light duty (perfect for an oven) - usually in the 23%-32% range (depends on the manufacturer and application).
medium duty - 33%-44% (again depends on man. & app.)
high duty - 45% and above (I believe he mentioned 67% being about the highest he had ever heard of and were rated at somewhere around 4000 or 4200 degrees F)

$4 Canadian or US seems pretty steep, based on the high alumina content the price is not surprising (high duty costs more here and are special order).

As for the castable - sounds simple, but is very tricky to work with. Stainless needles are recommended for reinforcement (not exactly cheap). The castable refractory is not cheap either (here in FL). If I remember correctly it would have cost me around $400 to cast my dome...I only spent $290 for all of my firebricks (210 total) and 2 bags of Heatstop 50.
The tricky part is the curing - most castables have to be heat curred at a pretty specific temp ; my question is - how would you cure the dome sections? You would need a friend with a very big kiln. I will admit, I gave the casting idea serious thought myself (the refractory dealer was pretty convincing after he found out he wasn't getting my firebrick or insulation business - prices were way too high); he really put on the hard sell for casting a dome or hiring his crew to do it.

I would shop around a bit more for low or medium duty (try to stay below 35% alumina and away from the insulating firebricks). Hopefully you can find some under $2 a piece, seems most of us in the US have paid from $.77 to about $1.80 each.



Artichoke 11-24-2008 10:26 AM

Re: Refractory brick in a bag?
Thanks RT,
With a little more looking around I found a source of firebricks at $1.37 CDN (9x4.5x2.5) which is around $1.11USD. The vendor did not know the alumina content but is a large local supplier and they are used for fireplaces etc. Well that is a large difference in cost. Is there a way to identify insulating firebrick?

I think I will pass on the casting method.

egalecki 11-24-2008 11:33 AM

Re: Refractory brick in a bag?
That's a pretty decent price. A non-insulating firebrick should weigh in the neighborhood of 8 pounds. A heavy duty one is much heavier. Insulating ones are a lot lighter. If the weight is about right, you have what you need.

RTflorida 11-24-2008 12:41 PM

Re: Refractory brick in a bag?
Insulating firebrick are usually a white color and only weigh 2-3 lbs. Elizabeth is correct on the weight - around 8 lbs. Fireplace bricks are almost always low duty and are the most widely available...they should work perfectly (they are what many of us, myself included, have used)


Bandrasco 11-24-2008 04:12 PM

Re: Refractory brick in a bag?
I know someone who is attempting to cast a modular oven. They are on their 3rd attempt and it sounds like it's getting better for them but they have had cracking issues, flaking issues, and one big boom when a piece blew off the side during curing... They said it was the size of a golf ball...:eek:

The bricks are easy to work with and you learn so much along the way. Plus you have everyone here to assist along the way!:D

Good luck!

Artichoke 11-25-2008 02:41 PM

Re: Refractory brick in a bag?
1 Attachment(s)
HI RT and Elizabeth,
I picked up a free sample of the fire brick mentioned in my previous post. It has very flat sides and seems very rectangular without any noticeable warping and good edges. It weighs around 6.8 lb. I think I have included a photo. It has a very faint embossing on one large face and I can make out one word. FLAME. There is another word I can not make out. Looks good

christo 11-25-2008 03:29 PM

Re: Refractory brick in a bag?
If looks mean anything (and I hope in my own personal case they don't..), it looks pretty much like the firebricks I used.

It would have been cool to have Bricks with "FLAME" on them for my entryway....


egalecki 11-25-2008 03:36 PM

Re: Refractory brick in a bag?
I think you're good with those bricks. They look just fine.

zeek 05-13-2009 01:03 AM

Re: Refractory brick in a bag?

Originally Posted by Artichoke (Post 45769)
With a little more looking around I found a source of firebricks at $1.37 CDN (9x4.5x2.5) which is around $1.11USD.

Is this in the Vancouver area? Where did you buy the bricks from?

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