36" Pompeii Dome - Thailand

[UtahBeehiver]

The opening in the top of the vent chamber should have at least the same area as the ID of the chimney, 8" ID chimney equals 3..14 x 4 x 4 or 50.14 sq inches so the opening in the vent arch should be at least this amount with a smooth transition from rectangular shape to square or round..

[danhem]

Making progress now, slowly but surely. In to the 7th course and hope to close in on the run over the arch tomorrow. Seems that as the courses go up each brick requires a cut. Not sure Ive mastered the art of the bevel as my joints are not a tight as many others Ive seen here on the forum. However I'm not too worried as I'm just simply glad to be closing in on the dome closure.

My attention is now focussed on doing a good and neat job of the outer-arch and chimney. I'm guessing that the outer-arch will be easier than the inner, but I'm currently unsure on the specifics of the vent area.....surely this part of the build doesnt deliver the same level of head damage that the inner-arch gave?

[danhem]

Sorry for replying so late to the thread, i just got around to reading your build after your comment in my build thread, but looks like youve already sorted the problem and done a great job too, its all pretty easy from now on up until you make your chimney transition! good luck!

Thanks Brad, yes things have somehow come together. Moving on now up the courses and will spend the coming weekend on what the hell to do with the chimney!

[brad mole]

Sorry for replying so late to the thread, i just got around to reading your build after your comment in my build thread, but looks like youve already sorted the problem and done a great job too, its all pretty easy from now on up until you make your chimney transition! good luck!

[danhem]

Looking good. I've spent hours staring at mine. That's funny. The transition from ring to dome is awsome.

Yes very much looking forward to the next couple of days. Just enjoying the build without the frustrations and complexities.

prepared for more of the troubled times some time soon...but for now it’s all good

[Mongo]

I couldn't stop staring at mine. LOL.

Ricky

Looking good. I've spent hours staring at mine. That's funny. The transition from ring to dome is awsome.

[danhem]

Nice! Yes I agree. when I built my dome and saw it coming together I was awestruck on how cool it looked. The more you keep building the cooler it looks because right now you see the way it looks getting fat and then it starts to narrow again as you close it up. I couldn't stop staring at mine. LOL.

Ricky

Amazing how the thing evolves from a pain in the ass to a thing of beauty....sure I'll be cussing it again before long.

[Chach]

Nice! Yes I agree. when I built my dome and saw it coming together I was awestruck on how cool it looked. The more you keep building the cooler it looks because right now you see the way it looks getting fat and then it starts to narrow again as you close it up. I couldn't stop staring at mine. LOL.

Ricky

[danhem]

A huge day for me today after tapping the keystone on of my inner arch in place to see the other arch bricks crank tighter into place with each tap of the keystone. Definitely a day to feel pleased after last week;s problems with the IT and he inner arch concept itself. A few days of waiting time before dropping the form but I'm pretty confident that it could come out tomorrow without any issues.

Managed to continue with the courses and have pretty much competed course five with course six scheduled tomorrow. I began to try and bevel the bricks to avoid the inverted V. Not sure I've got it totally right but it seems to flow quite nicely on the eye. I hope to get better at this practice as the courses progress from here on in.

I defiantly plan on taking the next day or two easy and expect to complete course 6 and 7 before turning my attention on to the vent and outer arch - something that up until now has seemed a distant task.

I am also watching out the 'Dreaded Droop' - not really sure what this is but fully expecting to see it on my build at some point what ever it is

How the oven will eventually perform remains a worry but what I can say is how amazed I am at the sheer beauty of the dome as it grows, its curves and its angles. Truly worth the effort so far.

[danhem]

Feel like some sort of breakthrough has been made on my inner arch today. Visually the brick cuts pointing to the inside of the oven seem correct however they do look a little steep. I've used all the tools at my disposal to make the checks and i'm fairly confident that the next courses will fit nicely on top of the inner arch cuts. It's been a really difficult concept to grasp and the cuts were a challenge, so it feel like a major milestone has been achieved with this build.

Looking from the outside of the oven at the inner arch bricks, I do wonder how they will set once mortar is applied. I see many builds here that taper the bricks to create a tighter fit. Is this a recommended practice or does my arch have a chance of holding? I plan on applying mortar tomorrow and will leave it to set for a number of days before removing the form. Fingers and toes crossed at that point

I am also starting to understand what folks have referred to as the 'Inverted V'. As the courses go up the bottom joint of the bricks is becoming way too wide for my liking. I'll look top bevel the bricks from here on in to tidy those joints up for aesthetics and more importantly heat containment.

[danhem]

You just need to make sure the TDC arch brick sits within the dimensions of the shell of the dome like I drew in the link. There are a few inches of fore/aft positioning that will work - I chose a more forward position to maximize arch stickout. You just don't want to have to deviate from round when the dome bricks go over the top of the arch. In the attached link my opening height is 12.25 inches, so the brick shown is virtually sitting on my arch form.

Ok thanks, I had seen that before and will pay closer attention to it now.

I had to laugh at some of the points you made in that particular post...."I think a lot of us come to the forum looking for "place it at X inches" and are disappointed that we can't find that kind of detail, but as cliche as it sounds if you can't figure it out yourself you aren't ready to build your oven"

Hoping to overcome this issue today, it's not really holding me back, seems that most others here have struggled with this exact same same concept.


Thanks again for taking the time to help.

Danny.

[JRPizza]

You just need to make sure the TDC arch brick sits within the dimensions of the shell of the dome like I drew in the link. There are a few inches of fore/aft positioning that will work - I chose a more forward position to maximize arch stickout. You just don't want to have to deviate from round when the dome bricks go over the top of the arch. In the attached link my opening height is 12.25 inches, so the brick shown is virtually sitting on my arch form.

[danhem]

Here is a pic of a tapered arch by MrChipster that is similar to yours. Notice how each brick is different and not linear but skewed. Remember you are after 63-65% of the dome height for the inner arch height, not so much the number of bricks to make fit. The flatter the arch the more outward pressure on the vertical walls, too flat and you may have to buttress the vertical walls. Also the placement of the arch form seems a little to far forward from the bottom vertical course. Notice in the pic that I sent you and this one as well where the bottom of the form lines up with the curve of the dome at the floor. Last thing, your start marking the tapered inner arch bricks at top dead center the work your way down left and right of TDC,

Ok thanks, big help. The positioning of the form has been a head scratcher. Makes sense to position at radius point of the oven entry.

[UtahBeehiver]

Here is a pic of a tapered arch by MrChipster that is similar to yours. Notice how each brick is different and not linear but skewed. Remember you are after 63-65% of the dome height for the inner arch height, not so much the number of bricks to make fit. The flatter the arch the more outward pressure on the vertical walls, too flat and you may have to buttress the vertical walls. Also the placement of the arch form seems a little to far forward from the bottom vertical course. Notice in the pic that I sent you and this one as well where the bottom of the form lines up with the curve of the dome at the floor. Last thing, your start marking the tapered inner arch bricks at top dead center the work your way down left and right of TDC,

[danhem]

Inner arch - I can almost feel it but something isn't clicking. I have 3 courses built and the arch form to start with 3 bricks in header position. Seems that to match the 4th course, the arch should begin to curve toward the top center of the arch, bricks facing the oven must be tapered to allow the 4th course bricks to run over the top of the arch taper? Apologies if this is not worded correctly but it's still a little hazy in my head.

Trying to use the IT to visualize this. I made a very rough pencil line to represent an arch brick cut that would flow with the IT.

I need to wok on the actual arch to make the fit as tight as possible. Based on the picture for my inner arch entry, is there a number of bricks I should look at using to make the tightest fit?