Making your own Firebrick

[MatarazzoDesign]

Hi,

I'm still trying to figure out the best method for building my oven. I've considered many options, the two most popular are: casting a one piece (or multi-part) dome/landing out of refractory concrete, or sucking it up and learn how to properly build a brick dome.

After months of bothering my wife with my endless pros/cons of different oven methods she suggested that I just make my own firebrick dome sections in our electric kiln. To my knowledge I haven't seen anyone do this (though I'm no expert). We have a good size kiln, about 20" in diameter and maybe 30" deep. I figure this would be large enough to fire one dome section at a time.

Would you recommend doing this?
I don't know the makeup of firebrick, but I assume one of you fine people do.
Would I be able to make a dome section mold and cast the firebrick, then fire it?
Any idea on what temp, how long/ how many firings are needed?

Also would I be able to use re-purposed kiln shelves/ kiln rings as structural components for the oven?

Thanks for your help!

[Les]

Re: Making your own Firebrick

That sounds like a whole lot of work. I would suck it up and learn how to lay brick ( it really isn't that hard).

[texman]

Re: Making your own Firebrick

I agree with Les. Cutting and laying brick sounds way easier than that.
Tex

[rsandler]

Re: Making your own Firebrick

I seem to remember this was asked once before, by another person with a small kiln. The upshot is that firebrick are fired to really high temperatures, and have to be fired repeatedly in order to get everything fully vitrified. Or something like that. Try searching the forums and see if you can find the old thread. It would be super time consuming and probably be rather expensive in terms of energy.

And both Les and Tex are right, building a brick dome isn't that hard. If you feel handy enough to pull off forms for dome sections, you're surely handy enough to cut and lay firebricks in a dome.

Edit: Found the old thread, here: http://www.fornobravo.com/forum/f44/...cks-17477.html.

[david s]

Re: Making your own Firebrick

You may be on to something here if you have access to some suitable clay body. Preferably one containing a high proportion of grog. Groggy clay fired to very low temps (around 800 C) actually has better thermal shock resistance than higher fired bodies excluding porcelain. eg the clay wares of Sth America that can be placed directly on the stove. Italian biscotti ovens are traditionally made from low fired clay. You would still require a lot of firings in your little kiln and the cost of firing plus the labour of making the bricks or sections would probably make the project unviable.

[MatarazzoDesign]

Re: Making your own Firebrick

Hi All,

Thanks for your feedback. I'll look into the original post and see how big the obstacles are.

The Groggy clay idea is very interesting, I'd like to look into that and see what I find.

Thanks again!

[nachtwacht]

Re: Making your own Firebrick

You have a kiln so I can only assume that it will not be the first time you are going to fire something in it... It started me thinking about what might be your biggest "problem".

Professional factories that make firebricks have very special equipment. A vacuum pressing is one of those things. They press the clay, push out all the air, and then bake it to get the resulting firebrick. This will get very dense firebricks wich are very nice for wood fired ovens since it will give you a lot of thermall mass and other good qualities.

Now you are thinking about making your own firebrick dome sections... I ofcourse might be very wrong, but I doubt you will get close to the quality that normal firebrick has. You might use the same % alumina etc. etc. but you will never be able to get the same density.

Another problem that you will get is that you will very likely get a lot of shrinkage. (not sure if I spelled that right, not a native english speaker but I guess it will atleast sound right ) I think before you are able to get nicely fitting sections you will get a lot of trial and error or... sections that just do not fit perfectly. A one piece dome will atleast not have that downside but it will have others and from what I read, big chances of developing cracks...

I do believe it should be very well possible to use refractory concrete, but my idea would be to do that in the exact spot where the oven is going to be... not fire anything in your kiln, just pour it, in sections, in the spot where you are building your oven. Use refractory concrete like it is clay, make several sections.

In the end, if you want to do it yourself, laying bricks is not all that hard. Using a sand mould, it should definatly not be so hard and it will fit perfectly