Re: Not enough heat

Posted by Rado (144.134.149.120)

In Reply to: Not enough heat posted by Richard

Hi Richard, thank you for helping with the allergy, more on it further below.

Okay, lets get back to the oven (Richard, I am writing here a bit more in general for everybody, I hope you don't mind that) ... refractory mortar shouldn't be used in thick applications, application in bulk won't last it would start to get loose pretty much after the first firing. Thinly applied mortar lasts perfectly or less mortar usage is always the way to go. If you had larger open place, some awkward somewhere between firebricks (such as in corner where the spot is not required to be part of or hold the heavy ceiling above etc.) you could use mortar with lots of firebrick grog/pieces mixed in that prevents shrinking and can help. But in most situations cutting brick to size equals long lasting e.g. in round igloo. Cutting brick job size depends on what type of chamber is being built, igloo requires heaps of cutting if one wants to make it well, rectangular floor ovens a lot less. And Masterly Tail ovens, whose I build, need very little firebrick cutting (they are efficient, suitable for various cooking of up to 6 hours from one heat up further more on top of that 10+ hours drying time and they look nice on a property too ;o)

2 ½" fire bricks (or 64mm bricks) are great for building ovens, use below link to one other posting on this! Thinner side bricks form arch of more bricks and this makes gaps between them smaller, also the arch looks smoother when one looks inside the oven, that's only cosmetic though. 2 5/16" (57mm) are fine as well i often use them as in end arch firebricks, all you do is only to create same oven internal dimensions even if you used many more 1 ½" (32mm) or 2" - 51mm size firebricks. 75mm - 3 inch firebricks are great too of course, the size that I can get I use.

*** E.g. for walls and arches made of firebrick sizes: 230x114x64mm (9"x4.5"x2.5" OR 8.5"x4"x2.5")

Option 1: stack three bricks on their side and create an arch with 16 bricks to come up with a total height in the vault at 420mm - 16½"

Option 2: stand the bricks on their side and create an arch with 15 bricks and come up with a total height in the vault of 413mm - 16¼"

You can get the true 407mm - 16" with any size fire bricks exactly (also with splits 51mm - 2" thin) by adding one more bricks to the arch and push both arch-sides (not walls) sideways a bit lowering the center down, 8-3/4" x 4-1/4" x 2-3/8" too. The 12.5mm - 1/2" will not make difference in chamber height but make entry 254mm - 10". I kind of like option 1, it has more of a nice arch to it. But both are perfect for heating.

Ovens made of firebricks are made of many clay fragments and when in fire everything nicely moves not cracking. In manufacturing process firebricks are stabilized (fired) in large industrial kilns, most of them from the line are used back again in other refractory industries. Many for generations, bakers use rectangular or square floor brick ovens for they last long, anything can be cooked in them, and who else needs evenly heated oven more then bakers. Clay lasts very long time and withstands a lot higher temperatures as we know can be reached in a wood oven, is natural not toxic and for brick ovens not costly too, think of these 9 biggies when wanting to pre cast your oven.

I am looking at your oven/BBQ-grill photo; I can imagine these 2 3" stainless steel pipes behind the brickwork as definitely very small throat start where the smoke would most definitely get out through the front entry-deco opening making it black. Have a look at both ovens on how I did the width and depth of the area where fumes exit the oven, also the depth of the vent is very important, exhaust flow has natural volume and speed - if you squeeze it not all smoke goes in and up throughout the right way into the chimney. Then from that vent size you can gradually narrow it upwards into hot air passage and into these 2 pipes. More on smoke problems that often happen to people. r

• More on firebricks.

• My favorite activity - 4-5 hours slow roasting/smoking (out of one heat up!)

• Avoiding smoke problems making oven front black.

PS
Your cousin who is a pharmacist is very right about the Claratin I must say, it does work very well (at least in my case.) After taking one, only when needed, it does the work perfectly I experienced for about 10 times by now (winter is always a bit mild.) We have here allergy tablets called Claratine and these seem to me have to be taken constantly every day for it to work, meaning taking chemicals and paying for it daily. Thank you for the generic version substitute info, and even more for posting a sample to me, I will test it and if worked the same it would be a big plus apart knowing the Claratin. I will most certainly let you know how I went, a big help, and also will have to say hallo to your cousin in some way.

Re: Not enough heat