Fire brick question

[Alpharavin]

A family member of mine recently gave me a whole bunch of firebrick he got from a job (he does a bit of everything) used for commercial pizza ovens. The thing is they are massive! They are 18.5 cm long 10 cm high, with three different widths, curved in a sort of wedge shape. I've never seen firebrick like this before

I read on a forum that walls should be about ten cm thick. If I use these as is, will it take forever to get this oven up to temperature? I've been looking everywhere but I can't find anything like these. Can I use them, or am I looking at a whole bunch of cutting?

Any help would be greatly appreciated!

[Yokosuka dweller]

Massive bricks, but they do look great. I guess reusing these as they are would be a bit of a puzzle, but given the bricks are already curved it looks like they could be stacked to fit rather nicely, provided you can solve the puzzle as it were. At the same time, cutting them looks to be a headache, since they're also over 20cm deep aren't they? So you would probably go through a whole lot of saw blades (or even sacrifice a saw) to try and cut them to a more manageable thickness. And also, if using them as they are they probably require a lot of firing to get up in temps given their massive thickness. Probably from an oven that could stay hot over night in a pizzaria or bakery and was then fired regularly to maintain the heat stored in the bricks.

Not sure what I'd do here; probably try and cut one of them to half depth and see how difficult that was before deciding whether to use them or not.

[Chach]

Fire brick in the US is usually 9" × 4.5" × 2.5" and are usually cut in half to make roughly 4.5"×4.5" piece to construct the dome. Yours seem to be around 7.25"× 4" if we convert to US measurements. Yes you would be using a lot of fuel to fire the oven. I would cut them but you also have to make sure on the inside of the oven brick touches brick and minimize any motar joints that face inside to minimize mortar joint reakdown as well as it is a neater cleaner look IMO. So if you square them up a little you will be fine.

Ricky

[Alpharavin]

Thanks for the reply!

they really are a puzzle. I've got a couple of different shapes in there too. I think they were originally designed for a massive barrel shaped oven or two,b they have passed through too many hands for there to be any instructions.

I'm going to try cutting one down tomorrow. I might have to use a grinder and a chisel for these. According to the wife, these are the only bricks I'm allowed (they were free), so if I want a pizza oven I'm gonna really have to work for it....

Should I try for a 10cm thick brick?

[UtahBeehiver]

These bricks appear to be from an industrial process such as a steel or glass melting kiln. It is possible these bricks are what we call "super duty" which are high in alumina thus very hard. It is feasible to have a 4" high course (10cm) it means you will just have less courses. By cutting the 18 cm in half you will end up with abt a 3.5" wall, which should be enough thickness for an oven as long as you insulate well. Caveat emptor, super duty bricks are hard to cut and you will go through the diamond wet saw blades. I do not thinks with the large diameter of the arch of the bricks that there is a need to square up you will not see any appreciable arc. You may actually get 4 dome bricks with those 21 cm bricks.