Perth 42" Pompeii - dome to flat entry integration

[jab49]

I'm about to start the first course with high heat mortar. Before I do that, am trying to visualise how the dome will integrate with the oven opening. I'm going to use angle iron for a rectangular, 20" entry - I'm just not skilled enough to do an arch, unfortunately.
See attached pictures. Questions are:
1. The two (three in the last picture) vertical half bricks these will eventually be 4 to make the height of the opening - should I mortar them like normal bricks? I'm thinking it would make them stronger, and also lift them sufficiently to allow the next chain on the dome to sit on top of the angle iron.
2. Is the general arrangement as shown for the oven opening acceptable? I've left a reveal for the door. Trying to minimise cuts, keep it simple. It won't look as nice as most I've seen, but is it going to work?

Kind regards
John in Willetton, Perth, Australia
Build progress: Wood Fired Oven - Perth - Forno Bravo Design

[brickie in oz]

Re: Perth 42" Pompeii - dome to flat entry integration

to allow the next chain on the dome to sit on top of the angle iron.

You need to keep angle iron out of the equation, it will distort and rust.

[azatty]

Re: Perth 42" Pompeii - dome to flat entry integration

If you can build a dome, you can build an arch. You can build an arch form from plywood and lay the bricks on it as you go.

I bulit most of my arch without a form. The trick is to not rush building the arch if you don't have a form. Lay a course on each side and let it set before going on to the next course. The mortar will hold the bricks in place mostly by itself, an you only need a stick or brace (indispensible tool works well) to keep it in place. I used bricks and brick slivers to brace mine while it was going up.

[C5dad]

Re: Perth 42" Pompeii - dome to flat entry integration

John,

I too struggled to visualize the arch tie in and asked many questions. No problem there, that is why we are all here with different experiences, etc.

I found that my mud set really quick because I mix "hot" batches with low water. Just the nature of where and how I work - time is of the essence during a plant turn around. None the less, I would highly recommend that you look at similar builds and email the guilty parties - after all, we are all of the Forno Bravo Familia and will stick together!\

Just remember, more joints, more potential problems. However, if you look at some of the old pictures from the trips to Italy, you will see all sorts of "refractory" mudded together. Whatever works for you will work, just go light on the mortar is all most will recommend.

Best of luck!

Chris

[jab49]

Re: Perth 42" Pompeii - dome to flat entry integration

If you can build a dome, you can build an arch. You can build an arch form from plywood and lay the bricks on it as you go.

I bulit most of my arch without a form. The trick is to not rush building the arch if you don't have a form. Lay a course on each side and let it set before going on to the next course. The mortar will hold the bricks in place mostly by itself, an you only need a stick or brace (indispensible tool works well) to keep it in place. I used bricks and brick slivers to brace mine while it was going up.

Thanks Azatty and co - I'll give it a go! I will make a form, go slow and steady as you suggest. Just some process questions then:
Do you recommend that I taper the bricks for the arch?
Did you get the arch built well ahead of the dome (ie, did you lay, say, 3 chains of the dome, then built the arch, then returned to the dome?

Thanks
JT

[Laku]

Re: Perth 42" Pompeii - dome to flat entry integration

Tapering the bricks will make it stronger.

[Cheesesteak]

Re: Perth 42" Pompeii - dome to flat entry integration

I built my arch first (on top of the floor) and then built my dome and just cut each brick where it intercepted the dome. If you place the arch in the correct spot - the end bricks in each chain will "wrap" the arch (each end brick of mine was cut in a "v" shape).

The arch was quite simple and each chain finished itself. No calculations, no compound miter cuts for me. It's certainly not as pretty as some of the arch / dome transitions you'll see - but it works just fine and I don't have any cracks or mortar issues to speak of.

Here are a couple of pictures . . .







Do what you're comfortable with - but I'd really suggest building the arch and not using angle iron. There's a ton of information here - and folks have built these things so many different ways and most, if not all, work just fine.

[Amac]

Re: Perth 42" Pompeii - dome to flat entry integration

If you want a semicircular (or near) arch, it will tie into the dome nicely - look at Giannifocaccias, KarangiDudes, Aceves and Sharkeys. I based mine on theirs because the dome walls attach with a straight cut and also the arch inside has the same convex shape as the dome inside (no ash traps)
I used a variation where I was able to cut all the arch bricks identically in advance and built the arch first. I too thought I would not have the skills to do it but it worked out really well, and much easier than I expected.
see post #36
http://www.fornobravo.com/forum/8/39...i-17334-4.html
I hated the idea of angle iron also - but I am sure there are lots of working ovens with angle iron framed entries
Good luck
Amac

[jab49]

Re: Perth 42" Pompeii - dome to flat entry integration

I built my arch first (on top of the floor) and then built my dome and just cut each brick where it intercepted the dome. If you place the arch in the correct spot - the end bricks in each chain will "wrap" the arch (each end brick of mine was cut in a "v" shape).

The arch was quite simple and each chain finished itself. No calculations, no compound miter cuts for me. It's certainly not as pretty as some of the arch / dome transitions you'll see - but it works just fine and I don't have any cracks or mortar issues to speak of.

Here are a couple of pictures . . .







Do what you're comfortable with - but I'd really suggest building the arch and not using angle iron. There's a ton of information here - and folks have built these things so many different ways and most, if not all, work just fine.

Hi Cheesesteak

I like what you have done (I like the other approaches too, but yours looks simpler and easier to me). Can I check a couple of things with you?
1. Confirm that you have just used standard half bricks on the dome (no tapering)?
2. When you said that "each chain finished itself", what do you mean?
3. Any chance you can let me know the dimensions of your arch span, height and dome diameter?
4. The top of your arch - looks like two bricks set the other way in orientation - correct?
5. Did you draw out this arch on paper first or just lay it out in trial?

Thanks in anticipation!

Regards

John

[Cheesesteak]

Re: Perth 42" Pompeii - dome to flat entry integration

Hi Cheesesteak

I like what you have done (I like the other approaches too, but yours looks simpler and easier to me). Can I check a couple of things with you?
1. Confirm that you have just used standard half bricks on the dome (no tapering)?
2. When you said that "each chain finished itself", what do you mean?
3. Any chance you can let me know the dimensions of your arch span, height and dome diameter?
4. The top of your arch - looks like two bricks set the other way in orientation - correct?
5. Did you draw out this arch on paper first or just lay it out in trial?

Thanks in anticipation!

Regards

John

John -

1. On the arch - as you can see - I tapered every other brick or so. I did taper some when I moved up the dome. Just the sides - not top and bottom.

2. What I mean is that I started each chain in the back of the dome and worked towards the arch. They "finished themselves" because I was just left with a gap to fill. I cut a "v" in the last brick and they wrapped around the arch. It was quite a bit easier than I thought it would be.

3. Here's how I located the arch: http://www.fornobravo.com/forum/f8/l...tml#post111827
Again, this was much easier than I thought it would be. I just intersected a 12" radius arch into a 42" dome. The numbers don't lie . . . I drew a line 4 1/2" back from the outside radius of the dome and built my arch on that line. Everything else fell in to place.

4. Yes.

5. All I did was draw it out in the link in my #3 above.

[brickie in oz]

Re: Perth 42" Pompeii - dome to flat entry integration

We need pictures......

[jab49]

Re: Perth 42" Pompeii - dome to flat entry integration

Sorry, accidentally deleted my post, that didn't have pictures, so here's it again, in summary:

This may be the dodgiest build on the forum, but I have built an inner arch and first course. Note the many and varied mistakes - one could spend hours picking them out! Any resemblance to Cheesesteak's oven is purely coincidental, therefore! Before I move on, is there any reason to redo this arch? I'm not going to stand on it, that's for sure, but when is near enough good enough? Appreciate the mentoring to get me this far (originally it was going to be a flat entry and angle iron, remember?), but don't be shy in any advice or counselling you may care to give (such as "quit while you're ahead ... ha ha).

[brickie in oz]

Re: Perth 42" Pompeii - dome to flat entry integration

Carry on with the build, the dome will buttress the arch and stop it from moving further.

[jab49]

Re: Perth 42" Pompeii - dome to flat entry integration

Carry on with the build, the dome will buttress the arch and stop it from moving further.

Thanks Brickie. Sometimes one needs a little gentle encouragement to keep going.

Can I ask that you take a look at another post I just made, back in the Materials threads?
http://www.fornobravo.com/forum/44/r...a-13379-2.html

Not sure if you have used Silaset 40D, but not having worked with it before, I wanted to check it wasn't one of the products that the manual cautions against using (that are designed for indoor fireplaces).

Cheers

JT

[Amac]

Re: Perth 42" Pompeii - dome to flat entry integration

JT

Not sure if you have used Silaset 40D, but not having worked with it before, I wanted to check it wasn't one of the products that the manual cautions against using (that are designed for indoor fireplaces).

If I remember rightly it was airset mortars they cautioned against whcih is not what you are using.
Still some people use airset and it seems to work Ok. I think as long as the dome is covered from rain (tarp or something - you seem to have a roof of some sort) even the indoor.
stuff will be OK. It was the expense which finally turned me off the airset and I opted instead for the homebrew - which is widely recommended on here and I heartily endorse.
The arch will be fine. If you have 12" radius semicircle (as I think Cheesesteaks was) the dome should hit it consistently all the way round.
As brickie says once, the dome is built around it it will reinforce it from all sides - wait till then before you do the Sharkey test
That reminds me have to post my pic of the "jig on the dome"
looking good so far - keep it going
Amac