Cheap fire bricks for sale!

[nissanneill]

To all those oven builders within Australia looking for cheap firebricks, see:

Refractory/Fire Bricks x200, for fireplace oven or kiln | eBay

and also in Queensland:

http://cgi.ebay.com.au/Fire-Bricks-bulk-cheap-Maryborough-/280667194568?pt=AU_Building_Materials&hash=item41591184c8

Cheers.

Neill

[brickie in oz]

Re: Cheap fire bricks for sale!

Id have to be 100% sure of where the used firebricks came from just in case the were loaded with some nasty that will leach out with each firing.

[nissanneill]

Re: Cheap fire bricks for sale!

No worries with the ones from Queensland brickie,

Genuine fire bricks brand new. Quite a few of the slant variety.

At a starting bid of 99c each and around 30000 available, an opportunity for everyone wanting to build an oven.
Even I would buy 1000 if the freight was at the right price!

Neill

[Johnny the oven man]

Re: Cheap fire bricks for sale!

I have a container of new firebricks in my warehouse. They are standard size, 230x115x75 and are 40% alumina, can sell for $2:50 each + GST, in full pallet lots of 320pcs. This would be a much safer way to buy, offer only lasts for this container lot.

[mothy]

Re: Cheap fire bricks for sale!

Howdy,

Been trying to decide whta brick to use, being in Canberra the Canberra Reds seem to be the go for the cheap option... Just saw these on ebay though and was wondering if someone could tell me if they are any good...

"Vermiculite 20 pack fire insulator bricks pizza oven/fireplace 230 x110 x 29mm"

Can't find any info on there about Alumina content etc...

Cheers,

Tim

[nissanneill]

Re: Cheap fire bricks for sale!

Hi Tim,
usually red bricks are merely fired clay and are not necessarily refractory bricks. I assume that they have holes through their centres which indicate their house construction use. Some members have used these with some success BUT you need to ensure that they are suitable and will not break down/spawl with the heating/cooling that you will subject them to. The next oven I build will have fired clay solid clay paving bricks, cut in halves but they are fired at 1200˚C and although not as good as firebricks, will serve the oven well. Many ovens over here are made with them and they are performing well.
Hit your planned bricks hard with a sledge hammer and check out the bits that it breaks into. If it crumbles into small pieces and sand/dust, forget them, but if they break into hard but larger pieces, then i would use them.

Good luck,

Neill

[mothy]

Re: Cheap fire bricks for sale!

Thanks Neill,

I believe the 'Canberra Reds' that people have been using are the Authentic Fired clay variety, I'm not sure but I don't think they make them anymore but there are still plenty lying around from old demolished houses etc in Canberra, but I shall do as you say and get the old sledge out...

Any word on those bricks floating about on ebay that I mentioned earlier?

Cheers,

Tim.

[brung99]

Re: Cheap fire bricks for sale!

HI Tim,

The Vermiculite bricks you mentioned are insulating bricks, not firebricks. As stated in the ebay add - "Excellent insulator for your PIZZA OVEN, FIREPLACE OR WOOD FIRED HEATER"

They would be suitable for under the hearth of your oven , but not to be used to build the actual oven from.

Regards,
BRuno

[david s]

Re: Cheap fire bricks for sale!

"Hit your planned bricks hard with a sledge hammer and check out the bits that it breaks into. If it crumbles into small pieces and sand/dust, forget them, but if they break into hard but larger pieces, then i would use them."

Neill,
This is not a particularly good test for the refractory suitability of a brick. For example an insulating fire brick which is highly refractory crumbles easily and a standard firebrick is usually more crumbly than a solid red, although it way out performs it. Also the temperature the brick has been fired to is also not a suitable indicator of its refractory ability. It is the content of the materials in the brick that is the most important factor, things like high levels of fluxes, and oxides are not good and they are extremely difficult for the layman to test.

[nissanneill]

Re: Cheap fire bricks for sale!

Yes David but we are talking apples and oranges really.
People who cannot afford the high price of the ideal refractory products should be able to determine the alternatives and how to decide which work/last better/longer than others. Too often I see people who are misinformed and build with totally unsuitable bricks.

Neill

[david s]

Re: Cheap fire bricks for sale!

Ok, but smashing a brick with a hammer will not tell you what it is made of or it's suitability. All it will do is give you an idea of its strength and therefore, probably it's degree of vitrification, neither of which will tell you if the brick is actually suitable.

[Johnny the oven man]

Re: Cheap fire bricks for sale!

"Hit your planned bricks hard with a sledge hammer and check out the bits that it breaks into. If it crumbles into small pieces and sand/dust, forget them, but if they break into hard but larger pieces, then i would use them."

Neill,
This is not a particularly good test for the refractory suitability of a brick. For example an insulating fire brick which is highly refractory crumbles easily and a standard firebrick is usually more crumbly than a solid red, although it way out performs it. Also the temperature the brick has been fired to is also not a suitable indicator of its refractory ability. It is the content of the materials in the brick that is the most important factor, things like high levels of silica, fluxes, and oxides are not good and they are extremely difficult for the layman to test.

David s, this is not quite right. One of our former leading firebrick manufacturers in Victoria, for over 100 years, had a firebrick of 75% Silica which would have been their largest selling firebrick for wood ovens over the last 20 years. it had just 21% Alumina, and just 4% oxides, and with a bulk density of 2000kg/m3 was absolutely perfect for this situation.This would be regarded as a low duty refractory brick. Yes firing temperature has a small effect on suitability, as normal house brick are fired at 1050c vs 1350c of refractory bricks. It really does not make a big difference though as you point out.
In most cases, a sold red brick is pressed during its manufacturing process, the same as ALL refractory bricks, this gives the density. Normal house bricks, yes the ones with holes in them, are wire-cut, they come out of an extruder similiar to say Toothpaste coming out its container, and then just cut into required sizes, with no pressing. This is part of the many factors that influance the suitability of refractory products.

[david s]

Re: Cheap fire bricks for sale!

OK, high proportions of silica in firebricks is undesirable for high temperature applications because it has a tendency to melt, in the presence of high levels of fluxes. As an example of this I once built a small experimental kiln out of mud bricks. At around 1100 C the inside of the kiln melted off in sheets. This is not a factor for a WFO application because it doesn't get hot enough. It was certainly not my intention to mislead anyone. I have removed the silica reference in my post.