Sunday, May 6, 2012

Brick Oven Brick Cutting

REVISED NOVEMBER 26, 2018

As any skill is perfected, better and more accurate and efficient means are either discovered or invented.  So, in the cutting of accurate sets of bricks for any size brick oven, I wanted to eliminate large mortar joints and increase the accuracy and 'perfection' of the domes.
Fortunately, the refractory industry makes arch bricks in #1 and #2 angles.  In combination, these two pre-shaped bricks will form any size diameter oven dome.  The bricks, like standard fire brick, are 4.5" wide, 9" long, and tapered.


Accurate bricks make a perfectly round dome
This still leaves two angles that need cutting (rather than three).  I call the other two: wedge and skew.  Wedge is the angle that aligns the front and back of the bricks so that they form a circle.  Skew is the angle that is on the side of the bricks.  Without these cuts, the back and sides of the bricks will show larger and larger gaps as the dome goes up.  These can be filled with mortar but it is stronger to have the joints as small as possible.





The second aid in cutting accurate dome are the styrofoam dome forms I purchased.  These allow me to set the cut bricks in rings in order to check the accuracy of the cuts.  After pre-fitting the dome brick this way, I number and box the bricks for transport to the oven project site.
Roman cross keystone TBO method









PREVIOUS POST:

I built my first oven from Internet plans, with some modifications. 
Cutting fire brick is an essential aspect for building domed brick ovens.


I currently use a Rigid brand sliding compound 12" miter saw mounted on a rolling workbench (Rigid brand too).  It is portable so I can take it to project sites and cut custom shapes when needed.
It is the best of the saws I have used but not absolutely necessary.  My first oven was built with a simple Delta chop saw (but this took some mechanical acrobatics in order to get angles and the blade was 7' which was not always wide enough to complete cuts in one pass).  Next, I used an old Craftsman 10" radial arm saw (not a very strong motor but I could run a hose to spray the brick while cutting and speed the cuts).
Now I soak the bricks and cut them wet with either the Rigid or a commercial block, stone, and brick saw.
Cutting angles for each brick on each 'chain' or band on the dome becomes pretty obvious as you go.  Note that there are two important angles. The Wedge shape (as viewed from above) and the Skew as view from the end.   Since my goal was to eliminate internal gaps these two angles were most important (structurally too). The third angle (call it the Taper) is the formed so that the outside of the dome is tight.  I wouldn't recommend this for a one-off oven as it involves a ton more cuts.  In the past I have saved wedges from other cuts to fill behind the bricks so that the dome shape is formed.  Or I used wooden wedges as temporary spacers until the rest of the mortar set up.
Now, I cut sufficient bricks for a number of ovens, setting the angles on the saw and proceeding in the most efficient way to produce the 300 or so pieces needed for a 42" dome.

7 comments:

  1. Hello David
    My name is Hassan I'm in Canada I was reading on your website and looking at the domes pics the inside and the outside joint they are very nice the best ones yet.
    My plan is to build my own 42" pizza oven in was wondering if you can send me the compound angles for each ring of the dome if you have them on a piece a paper I'm using 65 to 55 mm tapered brick 9*4.5 inchs .

    Thanks

    ReplyDelete
  2. Sorry there David my email is chamlal_qc@hotmail.com
    Thanks again

    ReplyDelete
  3. Hi David - LOVE your build - wow - tight seams/joints and quality work. I'm in a real dither over the taper-cut debate for a one-off build. I read here that you recommend the wedge and skew cuts but are non-committal on the taper cut (for a one-off). You recommend wedging and mortaring the gaps in the outside of the dome as the mortar is refractory and should do it's job. I guess the inside tight seams are the key? Having said that - and following Hassan's inquiry above (I'm in Canada too!) IF I were to cut angles going up courses for a 42" dome - what would the angle be on each course to ensure a proper rise?
    I am making an IT but even these need adjusting going up and I need a guide to know to what extent the adjustments need to be made - any help is most welcome!!

    Grateful
    Barry

    ReplyDelete
  4. Hi David - LOVE your build - wow - tight seams/joints and quality work. I'm in a real dither over the taper-cut debate for a one-off build. I read here that you recommend the wedge and skew cuts but are non-committal on the taper cut (for a one-off). You recommend wedging and mortaring the gaps in the outside of the dome as the mortar is refractory and should do it's job. I guess the inside tight seams are the key? Having said that - and following Hassan's inquiry above (I'm in Canada too!) IF I were to cut angles going up courses for a 42" dome - what would the angle be on each course to ensure a proper rise?
    I am making an IT but even these need adjusting going up and I need a guide to know to what extent the adjustments need to be made - any help is most welcome!!

    Grateful
    Barry

    ReplyDelete
  5. Also from Canada, near Toronto. Looks like there many pottery specialty companies that manufacturerside skew fire bricks, specifically for the purpose of building pizza ovens. Unfortunately they all seem to be in the States and Eurooe, and Asia. There have to be some in the Toronto, or Hamikton area, which has a number of steel foundry companies. I will continue to search for you...lol...

    ReplyDelete
  6. Hi David,

    WOW, what great work... Fantastic.
    I was looking at building a 42" pizza oven here in Northern Ontario.
    I was wondering if you would have any input on because of the temperatures we get up here, sometimes -40 with a windchill of -55.
    If you can send me the angles, this would be greatly appreciated.
    Again, great work.
    Mario

    ReplyDelete
  7. Hi David, Hope u r doing well <in fact I have plan to build commercial oven with internal Dia 47" with height 21", could u please help me with the plan of cut angels ,
    Note my brick size 9 X 4.5 X 3"

    thanks a lot
    Samir Shaher

    ReplyDelete