My first question - use for storage heater bricks

[stefan]

Hi all,
I've started a small Pompeii oven build (only concrete base done so far) and have around 50 bricks out of storage heaters available.

I wondered how to best utilise them. Are they a good cooking surface, or useful for insulation? Or maybe as the first course of bricks?

Also (second question I guess) I saw one build on this forum that appears to have used standard red bricks for the dome. Is that a good option, or should I opt for fire bricks? I'd like to keep costs down so red bricks would be of interest but don't they get brittle and chip from the heat?

Cheers

Stefan

[slowfood]

Hi, I would use the storage bricks for the hearth, I actually used regular bricks and cement in my brick oven and it works fine and also is still standing after a 7.6 earthquake. I highly recommend the book "Your Brick Oven: Building It and Baking in It" by Russell Jeavons, Good luck

[bookemdanno]

Its all about the return for the investment.
Firebricks give the formula one equivalent.
You'll only need a dozen or so Heater Blocks for a hearth, and quartered they can make a decent oven dome! Faz made a whole oven, i've used them in the hearth under quarry tiles.
Make sure you insulate well underneath the hearth though!
Stay away from concrete bricks.

[faz]

I covered my floor with quarry tiles laid over the top of storage heater bricks. The dome is made from heater bricks, cut in to halfs, then quarters, then sixths, then eigths as the dome went higher. I also used the smaller cuts to make sure the joins were staggered in the lower courses too.

[cannyfradock]

Interesting comments from the guys. here's my thoughts......

I've used storage heater fire-bricks on the hearth of clay ovens I built, working on the principle that a Clay/adobe dome will not achieve the same temperature as fire-bricks so dome and hearth should have the same (or similar) refractory qualities. Any hearth MUST be laid on a 4" insulating layer....I use thermolite blocks.

As mentioned 42% Alumina en.wikipedia.org/wiki/Aluminium_oxide fire-bricks will be your first choice for hearth and dome (I just used 120 3" fire-bricks @ £1.20 each (not sure on exact prices) and 10 1" fire-bricks @ £1 each, to build a 90cm internal diameter Pompeii .....including the entrance arch. Overall cost with 3 bags vermiculite, thermal blanket, 2 bags powdered fire-clay including vat + delivery was about £400. I shall post exact pricing soon on my Corris Pompeii thread.( ukwoodfiredovenforum.proboards.com/index.cgi?board=pompeiiovens&action=display&thread=1031 )

I've also used clay bricks on my first Pompeii build...they work but obviously not as good as fire-brick. As yet they haven't cracked or "spalled" but I've read..they can.

If you go down the route of a storage heater hearth and clay-brick dome, I might be tempted to double up the hearth layer. Clay pavers would be an option for the hearth but if you have storage heater fire-bricks, I wouldn,t cover them with clay pavers. It's the Alumina content in the fire-brick which give's best refractory value.

I also used the same technique as Faz mentioned by using whole halves, then quarters, then eighths etc....but I had to squeeze a whole build out in 2 days so my dome doesn't look as aesthetically pleasing as other members builds....



Terry

[tonyb]

We've discussed the use of ordinary red bricks quite regulary without coming to any conclusion. I think that what we do agree on is that firebricks are thermally and structurally the best solution but are expensive and heavy, old reclaimed victorian bricks are generally considered ok becuase bricks were mostly fired at high temperatures then. Modern day bricks are probably ok but there may be some spalling and we don't really have much information how they will stand up to say 5 years of heating and cooling.

Anecdotally you will always get someone who said they had no problems with the red brick they used, which is good for them but unless you can get hold of the same type, there's no guarantee the brick you obtain locally is as good.

My own view is that is that if you are likely to be moving house in the next couple of years then build a cob/clay wfo, if you are planning on living at the same place for the next 10 years invest in a firebrick wfo. Any period in between, becomes a personal choice between clay/brick/firebrick.

[faz]

And don't forget that if you have some bricks you're not sure about, you can give them a test by getting them red hot with a blow torch, allowing them to cool, then repeating the process a few times. It isn't exactly the same cycle they'll see in the oven environment, but it will give you a good idea if there's going to be any gross issues with spalling or cracking etc.

I did it with my storage heater bricks before using them, just to be on the safe side.

[Aidan McGrath]

Apr 8, 2013 21:20:54 GMT faz said:

I covered my floor with quarry tiles laid over the top of storage heater bricks. The dome is made from heater bricks, cut in to halfs, then quarters, then sixths, then eigths as the dome went higher. I also used the smaller cuts to make sure the joins were staggered in the lower courses too.

[Aidan McGrath]

Hi Faz, How did the Storage Heater brick dome work out? Have you any photos? Did it crumble or crack at all?

[oblertone]

I used storage heater blocks for my hearth and common reds for the dome (see link below), and it is working just fine. Cutting SHB's would be a pain as they seem to have friable edges, not a problem on a floor as the gaps fill up with ash anyway; might be more of an issue as the inner surface of the dome.