42 inch Pompeii build i Norway

[Steellearning]

Started the build on my oven yesterday.. poured the slab 155 x 175 x 10 cm. I purchased all my building materials at one store (sand too) and had them lift everything in place on pallets. Saved me a lot of work.
I used 12 mm rebar spaced 25 cm center. The cement came in 20 kg bags so my mix was 25 lt. sand, 25 lt. crushed rock (gravel) 8 to 10 lt. water and 1 bag of cement. All in all I used 8 bags of cement. I thought this could be a one man job but after 4 mixes I had my son help out.. it was going too slow and my back was killing me. When I mix the tabletop I want 3 people involved.
I have around 300 refractory bricks that are arched (tapered) 230 x 114 x 67/61 mm (nice for the dome) but I still have to buy square bricks for the floor and entrance.
I'm thinking about using 4 inch siporex or ytong for my floor insulation (unless someone on the forum gives me reasons not to?) FB board is just to expensive to import to Norway. I might be able to get a hold of perlite so that could also be an option.
Thinking also on using home brew mortar but I need to figure out what fire clay is. I'm sure its available but I just don't know what to call it. Is it the same clay used in making pottery?
Looks like I'll be cutting my fire bricks with an angle grinder. I was hoping on buying an inexpensive brick/tile saw from Biltema but it only cuts up to 60 mm thickness. I'm posting a picture of it just in case someone on the forum thinks I might be able to use it.
Well that about wraps it up for now. Any and all advice will be greatly appreciated.

Arne

[jbruning]

Re: 42 inch Pompeii build i Norway

Hi Arne,
Looking forward to following your build!

[Greenman]

Re: 42 inch Pompeii build i Norway

Looks like you have done your homework and are organised. It is a job worth the doing and worth a few aching muscles.

All the best with the build. I will follow it with interest.

[Gulf]

Re: 42 inch Pompeii build i Norway

Arne,
I can't decide from the picture if that is a wet saw with a collection basin. If it is, you can probably make it work for you. The seived dust from the basin of a wet saw can be used for "home brew". The fire clay used in pottery can be used for home brew. If that is a wet saw you will have all the fire clay substitute that you will need. The diamond blade on the angle grinder will still be useful at several times during your build. From my search, the products you listed as insulation (siporex or ytong) translates to hebel. I see it used a lot in Australian and UK builds (i think) . Maybe someone else will chime in on that

[cobblerdave]

Re: 42 inch Pompeii build i Norway

Gudday
I have used "hebel" for the hearth of my oven 3 yrs now and still good.... But it is a cement based product and will be effected by heat over 300C. I always recommend that to be cautious and put a 25 to 50 ml layer of pearlite/cement over it to protect against the higher heat.
If you go ahead and build with brick bulster and angle grinder I can tell you that you will still be able to produce a strong and functioning oven . My own was built that way I don't suffer from anything more than a couple oh hair line cracks near the entrance, I believe an oven built this way is more able to expand and contract in heating and cooling cycle due to the larger amount of lime rich mortar.
Regards dave

[fabby]

Re: 42 inch Pompeii build i Norway

Arne, it looks like you have everything ready to go. I also used an angle grinder with a diamond blade, and a good masonry chisel and hammer to do 95% of my dome. I originally was going to purchase the Harbor Freight brick saw but they were backordered and I wanted to get going on my dome. Most cuts worked out pretty well, I did go through three blades though. Toward the end of my build, a friend lent me a wet tile saw to use. Not nearly as convenient but I did use for some cuts on my arch. All in all, I found that I was much better with the angle grinder. I would just recommend some ear protection while cutting as things get really loud..............what's that?...........say again?...............I'm sorry, can you repeat that?.....


Can you tell I didn't have the ear protection until the very end of my build.

[Steellearning]

Re: 42 inch Pompeii build i Norway

Thanks guys, for chiming in on my build... really appreciate it.
The blocks are cut and dry stacked. I mortared the first row to get things level and today I plan on filling them with concrete. My blocks are 50x20x20 cm, 50x25x20 would have been easier math wise. Thats why I have the two ventilation holes in my back wall .
The opening in the front is 110 cm and I've decided spaning a 15 or 20 cm concrete lintel over it. That way I can decide later on how big and how I want the opening to look.
I'll be putting 12 mm rebar in the corners and a run of rebar along the top of the third row of blocks. That should keep this thing together...
I'll be glad when the top slab is poured and I can start on the fun stuff.. my IT tool is just aching to get started.

[david s]

Re: 42 inch Pompeii build i Norway

Fire clay is used by potters for certain things. It is a very refractory clay ie. it can withstand extreme temperatures. I believe you don't really need a true fire clay because the oven will not see those really high temperatures (1200 C +) where high silica clays can turn to glass. Bricklayers clay should suffice. That's what I use and it works fine.

[Steellearning]

Re: 42 inch Pompeii build i Norway

Fire clay is used by potters for certain things. It is a very refractory clay ie. it can withstand extreme temperatures. I believe you don't really need a true fire clay because the oven will not see those really high temperatures (1200 C +) where high silica clays can turn to glass. Bricklayers clay should suffice. That's what I use, it's cheap and it works fine.

And the moment I'm thinking about using Chamotte?

Chamotte (Fired Clay)
Shaft and Pure White Chamotte is available. Qualities range from Al2O3 40.0% min ? Al2O3 46.0% min. Available sizes range from lump to milled fractions.

[david s]

Re: 42 inch Pompeii build i Norway

Go ahead with that if you wish, but using fired clay that has been crushed is really like adding an aggregate. The powdered unfired clay has much smaller particles and imparts stickiness to the mortar that the crushed fired clay will not. Some builders use the slurry left over from their brick cutting which is much the same thing as chamotte.

[Gulf]

Re: 42 inch Pompeii build i Norway

Go ahead with that if you wish, but using fired clay that has been crushed is really like adding an aggregate. The powdered unfired clay has much smaller particles and imparts stickiness to the mortar that the crushed fired clay will not. Some builders use the slurry left over from their brick cutting which is much the same thing as chamotte.

VeryTrue,
But, that depends on just how "fine" you decide to "screen/sieve" it . In your pan you will have every thing from brick chips to dust.

just say'n .

[Steellearning]

Re: 42 inch Pompeii build i Norway

Go ahead with that if you wish, but using fired clay that has been crushed is really like adding an aggregate. The powdered unfired clay has much smaller particles and imparts stickiness to the mortar that the crushed fired clay will not. Some builders use the slurry left over from their brick cutting which is much the same thing as chamotte.

If chamotte only acts as a aggregate, like sand, then I think I should be looking for something else.
I've seen pottery clay that contain small amounts of chamotte to minimise shinkage.
Does the fireclay and sand mixture used for leveling under the floor bricks harden?

[david s]

Re: 42 inch Pompeii build i Norway

If chamotte only acts as a aggregate, like sand, then I think I should be looking for something else.
I've seen pottery clay that contain small amounts of chamotte to minimise shinkage.
Does the fireclay and sand mixture used for leveling under the floor bricks harden?

it will harden if it gets wet.

[Steellearning]

Re: 42 inch Pompeii build i Norway

OK I've found a white pottery clay that contains 25% chamotte with a max grain size of 0,5 mm. Raw burn 960?C. Suggested burn 1220?C. I think this might work?
They also carry different grain sizes.

[david s]

Re: 42 inch Pompeii build i Norway

That sounds ok, but treat the Chamotte content as sand in the home brew mix when calculating proportions.