fire bricks

[boccu]

just got a quote for fire bricks from a local supplier .... a whopping $6.51 (NZD) per brick which would put the whole project out of budget if I would need to build both base and dome with them!! I asked for the technical specs and these bricks have 32% Al2O3 and 62% SiO2..... does this make them high grade and therefore not suitable for our purposes? Keep looking I suppose???

I had previously found another type of fire brick but have yet to get the specs for these. The only thing is that they are only about 2.5cm thick and are normally used in slow release night heaters. It would cost about $60 (NZD) to pave about 1.3sq meters so much more cost-effective if they are suitable. I have not come across anyone else mentioning this type of brick on the forum. I was wondering if I had a good thermal concrete beneath the floor of the oven would this be enough? I'll post the specs on this forum once I receive them.

[dmun]

That price is way out of line. I bought firebricks retail in the US for under $1. Ocean transport, at the container level, is close to free. Maybe you need to form a buying club and import a few pallet loads of firebricks.

[james]

Ouch. That's $4.50 (USD) a brick. That's not reasonable. Perhaps KiwiPete has a few ideas. When you can ship firebricks from the states to NZ for a lower cost than you can buy them locally, you know something is out of kilter.

Where to the masons who build fireplaces buy their bricks? I just took a look at weather.com, and Auckland doen't get a lot of frost at night in the winter. Is this a good fireplace region? Average winter low of 47?F. Not bad.
James

[boccu]

I'll keep looking ... I know that they cast firebricks somewhere in the south island so hopefully it should be cheaper to ship them from there rather than from the US?!

I'm still relatively new to NZ (came all the way from sunny Malta in the med. ). Remember NZ is a very long island running north to south, so the climate can vary from almost sub-tropical from auckland and above to polar around the south of the south island ....that's where most expeditions to the antarctic set off from!! so yeah ... It can get pretty cold and frosty and most houses would have fireplaces. which means there must be cheaper firebricks out there somewhere!

[wlively]

Australia??

You might want to look here;
http://www.traditionaloven.com

Brick oven builder in Australia. If you can't find bricks in NZ, it may be cheaper to get them from Australia than the US.

Good Luck,
Wade

[james]

Good idea on finding firebricks, but don't build that oven design.
James

[wlively]

Round is king!

Good idea on finding firebricks, but don't build that oven design.
James

I agree round is better.

[jengineer]

Fire Brick vs Insulating Fire Brick

Been doing a bit of a search myself as I had a line on 'Craigslist" for Firebrick at $0.50 each. Almost too good a deal to pass up on. Called the guy and found out the composition was in the proper range 30% AL and 55% SI-O2. Great just what a fire brick should be for our ovens. Then I asked for the density, he had no clue but said they were pretty light. Uh oh - that means it was probably around 2 lbs (1kg) not the 8 to 9 lbs (3.6 to 4 kg) that is used for low duty fire brick. Yep it was too good to be true.

James somewhat alluded to the differences in a post about how bricks are made and what puts the airholes in them. Althought the makeup of an insulating firebrick and a low duty firebrick may be the same the kiicker is in the density. Those air holes are what make insulting brick and the lack of them is what bmakes non-insulating (heat retaining) brick.

[boccu]

thanks for all that people! Managed to buy some 2nd hand fire bricks at $2.50 each (NZ) .... still pretty expensive compared to what you pay in the US, but a song cheaper than buying them new...... so we're off!!
cheers!
boccu