K79 Oven Build

[shuboyje]

Re: K79 Oven Build

I was told to pack any gaps over 1/8" with castable refractory. Opinions?

Huge overkill. I would personally ditch the Refractory mortar with it's 1/8" limitation, go to home-brew which is much more versatile and stop worrying about mortar gaps.

[Laurentius]

Re: K79 Oven Build

I was told to pack any gaps over 1/8" with castable refractory. Opinions?

My question to you was, who told you to pack the gap with 1/8" castable refractory? Someone from the forum or the saleman, if there were one? Just asking.

[K79]

Re: K79 Oven Build

By whom? The guy that sold it to you?

Nobody sold me anything it's just a question.

[Laurentius]

Re: K79 Oven Build

By whom? The guy that sold it to you?

[K79]

Re: K79 Oven Build

I was told to pack any gaps over 1/8" with castable refractory. Opinions?

[K79]

Re: K79 Oven Build

There will be an 1/8 gap between the first 3 courses because I'm putting 1/8" of mortar between the bricks and there is no arch to them. Thanks for the heads up about the chip. Can I make the last two on that side half width to remove the chip

[UtahBeehiver]

Re: K79 Oven Build

K,

I am not sure why you will have a 1/8" mortar gap on the side if you flush the bricks up against each other. One thing to avoid, that Tscar taught me, is you have a small brick sliver called a chip (right hand side by arch). You need to avoid this small a width of a brick. Adjust the widths on a couple of the last bricks on each side of the inner arch to make the last brick wider. I tried to make all my adjustment in the area. You cannot readily see this area unless you stick you head in the oven.

[K79]

Re: K79 Oven Build

Hey guys... I did a little re-design after spending 2 days home sick. I decided to lay all my bricks stretcher and we're going with a 36" oven. The first 3 courses of brick I'm leaving 6.5" long for a little extra wall at the base and I won't be putting any angle to them. That way I can keep my vertical wall at the edge of the oven that I wanted. I know that the brick is all supposed to be touching on the inside, but for these first 3 courses is it ok to have a 1/8" mortar joint on the inside?

Oh yeah, I now know that it isn't possible for the oven to turn out exactly like it looks on the computer

[Tscarborough]

Re: K79 Oven Build




The stucco serves as a shell with no structural purpose other than to contain the perlite. Italian Neapolitan ovens use a relatively poor insulator with enough compressive strength to buttress the sailor course against a structural monocoque stucco shell. The exterior on them gets very hot.

[Tscarborough]

Re: K79 Oven Build

Here is how I was able to use loose fill. I formed the stucco skin before I added the insulation, then filled it.









edit-note that in the last picture I have put the masonite back on to act as the grade for the edge when I stuccoed the roof. The perlite on the roof is basically wet perlite poured through the lathing.

[david s]

Re: K79 Oven Build

"I had a structural engineer from our other dept. look at my plans. Basically he told me that there isn't much difference between the soldier's and starting from the bottom using half bricks laid stretcher. The dome's weight will make the bottom brick (whichever way it is placed want to shear out). He wouldn't stamp either plan."

Structural engineers are just that and unlikely to have considered the expansion forces on the refractory, the extremely rapid temperature rise and uneven heating experienced by the structure in a real life situation. All the theory at hand is unlikely to be able to predict accurately the ovens true performance. This is only revealed to the oven owner with experience and observation over time.

[Laurentius]

Re: K79 Oven Build

This is how I handled it on a sailored course, I did not want to use the insulation as a buttress, I wanted loose fill.

Hi T,

Wonder why no one has tried loose filled, before, please keep us posted. P or V??

[K79]

Re: K79 Oven Build

That looks good. I spoke to a mason at the local precast around here and he said not to worry about any of that stuff too. Basically keep the joints as small as possible and neck down the height of the soldiers and no fiberglass in the mortar.

[Tscarborough]

Re: K79 Oven Build

This is how I handled it on a sailored course, I did not want to use the insulation as a buttress, I wanted loose fill.

[ATK406]

Re: K79 Oven Build

Hello K79,
If you do some research, and you probably have, you will find that some of these ovens have lasted for hundreds of years - using even more basic materials and less precise build processes than we are using today.

I suspect there are many Engineers on this forum and more importantly others with years of experience building structures like this. In my experience many projects are over engineered at the expense of the simplicity and beauty of the original design.

You can cut your bricks 6 ways from Sunday and wrap your oven in as many layers of steel wire as you wish...after all it is your project. But don't kid yourself that you are "fixing" or "improving" anything, because there is/was no problem with the standard design in the first place. You are simply adding more complexity, cost and effort for a very minimal increase in overall strength. If you think that is value added activity - have at it. Frankly that's what makes this site so interesting.

I apologize for the snarky tone of this post (criticism can be as hard to give as it is to take) but I think you should be careful not to imply that all of the other ovens documented on this site are structurally unsound. I'll be the first to admit that my own has some serious faults (pun intended) but I'm confident that it will continue to work and remain standing until somebody comes along and decides to tear it down.

I'll go home now and take my happy pills...as it's been a long week (Hopslam anyone?)

Good Luck on the rest of your build.
Sincerely,
AT