Clay Bricks, fire bricks or concrete bricks/blocks... various mortars as well ?

I have access to lots of residential fired clay bricks and I am trying to research why, if , and how much better fire bricks
are in building stoves etc. What happens if you dont use fire bricks and use regular bricks or concrete blocks/brick instead?
If I am facing certain failure in the future because of the wrong components, I dont want to waste my time using them.

I may be looking at a huge expense if I have to purchase fire bricks compared to free clay bricks. Somewhere I
saw a company that makes cast iron stove tops ( just the stove tops ) and I would like to build a brick rocket
type stove using these stove tops the way they do in a lot of 3rd world countries for economical indoor cooking.

If you find the company who sells stove tops only I sure would be interested in that also!

I do not know anything about bricks though but am sure that others on here do.

Common clay bricks will heat shock and fracture. Fire brick is composed of aluma/silica/shale clay, fired at ~2000F, and is much denser and more durable than iron oxide red clay.

New ones are a bit spendy, but keep an eye on Craigslist for free bricks. After ckecking the "free" catagory for weeks, I finally found someone who wanted a small brick and sand patio removed from their yard. Half of the bricks were smelter bricks, apparently leftover from the construction of the Kaiser plant in Mead. Stamped with "Laclede", "Farber" and "Walsh XX"... fired at 3000F... they are thick (3x4.5x9) and heavy as stones. They're going to be part of a 6" system I'm trying to get built before the winter solstice. Not only are they more than I'd hoped for while looking for used fire brick, they came with a little history as well. Free stuff is cool.

I too, have looked at old iron stovetops in the local scrapyard (also much cheaper than new ones) and have thought about using one to construct an outdoor kitchen in my backyard.

Here is an incredible design using an old iron top in a combo heating/cooking RMH:

http://donkey32.proboards.com/index.cgi?board=discuss&action=display&thread=11

Scroll down a bit to see detailed photos of the top during a burn.

From what I understand, regular brick just dosen't cut it for two reasons.
#1: It doesn't last. As Chris B mentioned it cracks and spalls very quicky and so have a very short lifespan.
#2: It's a heat sink. It is a form of thermal mass where what you really want in that part of your system is super insulation.

Whith this in mind people will use fire brick, BUT... be aware of two products that both go under the name of fire brick.
One is a hot fired high silica brick that is capable of withstanding the high temps you are hopefully going to get in your heat riser and combustion chamber. It is somewhat heavy like normal brick This, I belive, is what Chris B is talking about (good score Chris!).
The BEST brick to use is also called fire brick on this forum, but I think a better make for it is Kiln brick. It has lots of little air pockets in it and has a very high silica content. It is a very good insulator as well as being able to whitstand the heat of your rocket. This is your best choise for an efficient secondary burn.

The only drawback to kiln brick is it's dencity is low enough that it doesn\t deal well with abrasion. You fuel may wear it away, so I've seen some people use ceramic tile to line their fuel port, just for longevity.

Chris Sturgeon wrote:From what I understand, regular brick just dosen't cut it for two reasons.
#1: It doesn't last. As Chris B mentioned it cracks and spalls very quicky and so have a very short lifespan.
#2: It's a heat sink. It is a form of thermal mass where what you really want in that part of your system is super insulation.

what is the projected lifespan of regular fired brick? I guess it depends on how much you use it, but I have seen this brick and clay tile used in rocket stoves designs in the developing world. In the developing world, fire brick is impossible to find, so I guess that's why people use the clay brick. That brick has been fired, but not at the temps of fire brick.

Abe Connally wrote:
what is the projected lifespan of regular fired brick? I guess it depends on how much you use it, but I have seen this brick and clay tile used in rocket stoves designs in the developing world. In the developing world, fire brick is impossible to find, so I guess that's why people use the clay brick. That brick has been fired, but not at the temps of fire brick.

The difference is that rocket stoves (usually a short L-tube) will not reach the same temperatures that are achieved in the burn chamber of a typical RMH J-tube design.

Here's a Canadian suplier of Kiln Brick. http://www.pshcanada.com/kilnbuild&repair.htm

It's about $50 for a carton of 12 so, depending on the size of your stove, it may cost about $200 to build your core. That's about the cost of a cord of wood: http://news.sympatico.cbc.ca/local/yk/firewood_prices_hit_record_highs_in_yukon/d42aebf7

So, I think it's a totaly fair building cost.

Chris Sturgeon wrote:Here's a Canadian suplier of Kiln Brick. http://www.pshcanada.com/kilnbuild&repair.htm

It's about $50 for a carton of 12 so, depending on the size of your stove, it may cost about $200 to build your core. That's about the cost of a cord of wood: http://news.sympatico.cbc.ca/local/yk/firewood_prices_hit_record_highs_in_yukon/d42aebf7

So, I think it's a totaly fair building cost.

yeah, for Mexico, that is 14 day's worth of wages. Wood is typically free in the developing world.

In areas where they are available, they might be relatively affordable, but they are typically not available in the developing world. That's why the clay tiles and bricks are used.