Todd's Oven

[toddj]

Re: Todd's Oven

Thanks DrakeRemoray!

[toddj]

Re: Todd's Oven

Hello Elizabeth,

Ya, the two bricks for the chimney are just there for reference at the moment. My plan is to have an arch in the dome, then a small gap, then just in front of it a slightly larger arch to support the backside of the chimney, then a gap of one brick to let the smoke enter the chimney, then a front arch to support the front of the chimney. So my chimney will be free standing of the dome and it will be 1.5 bricks deep with an alternating interlocking wall up to the arches. My arches are interlocking tapers. Hope that made sense...

Once I get the two chimney arches built and the clay chimney tubes set Im going to form in around the whole chimney all the way down to the slab and fill the form with vermiculite/portland mix. This should lock everything together.

This 'I think' will allow the dome to expand and contract without exerting force on the chimney and the chimney mass will not be wicking heat away from the dome. Im leaving about a quarter inch gap that I will fill with a flexible woven ceramic oven seal.

My chimney will have a lot of mass and Im planning on capping it with an antique English chimney pot.

[DrakeRemoray]

Re: Todd's Oven

Great work Todd!

Personally I vote for mortaring the bricks in place.

Keep the photos coming...

[egalecki]

Re: Todd's Oven

Hey Todd- I was looking at your pics from the photo gallery. Your bricks for the opening arch side are cut almost exactly like mine were. That shape worked really well, but if I had to do it over again, I'd make them so that I had full and half sized bricks alternating, so that the landing bricks lock with the arch sides. I had to buttress my arch landing sides because they were separate from the oven itself and wanted to tip over when too much weight pushed on them. If they were locked in with the oven, that would have not been as much of a problem.

You may be looking to make a complete thermal break, but I don't think that's even necessarily desirable in this case- the flue needs to get hot to draw the smoke up properly, I believe. When my oven is red-hot (well, white-hot) the front bricks have been quite hot to the touch, but they haven't been so hot I couldn't touch them.

Just my two cents.

[dmun]

Re: Todd's Oven

I do believe that because of the expansion, you will find pieces of heat stop lying on your floor.

Not a problem. You sweep the floor before making pizza, after all. This little bit of heat stop may not help, but it isn't likely to be a problem. Most of the fragments will just end up in the ash between the bricks.

[toddj]

Re: Todd's Oven

Ya, I was wondering how much would pop out.

[Les]

Re: Todd's Oven

then I filled all the cracks with a very wet heatstop mix using a grout tool and followed that up with a damp sponge.

I just went back and read through this post - the above may cause an issue. I think structurally, there is no harm. I do believe that because of the expansion, you will find pieces of heat stop lying on your floor. After a few fires this is probably a moot point. You want your floor flat so the tools don't catch (duh). I used a belt sander to get it true. The general consensus is that the ash will fill all the annoying voids.


Les...

[toddj]

Re: Todd's Oven

Thanks Les,

Im not holding them, im a chicken... I made a jig that holds the brick on both sides.

I dusted the vermiculite/cement slab with dry heatstop, pulled a toothed trowel through it then laid the bricks on top and tamped them down. The heatstop started sucking water out of the vermicucrete slab as soon as i put it down.

[Les]

Re: Todd's Oven

Todd,

Normally the floor is leveled with fire clay and sometimes sand. I don't know if anyone has mortared the floor to the board - probably no harm.

As you go up in course, the bricks become thinner. The gap angle is no worse or no better then the beginning. It's a curve with a constant radius. The problem I had was holding the thinner brick sturdy enough to get a good cut. If you have the will, I believe it can be done - make us proud!

Les...

[toddj]

Re: Todd's Oven

well i got kind of agrivated with the floor.. I never leveled it so i took everything down and leveled it on heatstop. then I filled all the cracks with a very wet heatstop mix using a grout tool and followed that up with a damp sponge..

[toddj]

Re: Todd's Oven

good point dmun! I was just thinking about the delta gap that forms as the radius reduces.. Hmmm... I am numbering everything...

Mike.. its here and 200lbs is a lot smaller than it sounds..

[mfiore]

Re: Todd's Oven

I think you have too much Heat Stop coming!

[mannextdoor]

Re: Todd's Oven

I wish I had the talent to try it. Theory says that it should work.

[dmun]

Re: Todd's Oven

As you approach the top, the flat, brick to brick mating is lost, even cut sides and top don't compensate for the gaps that form between bricks. If they are tapered in two dimensions, they are unlikely to fall through, but I think they are much more likely to shift.

Me? I'd number the bricks on the backside so if they end up in a heap you can go back and figure out how they go together if there's a problem.

One consideration is that if it were a full dome it would be immensely strong, with the downward forces evenly distributed, but that big hole in the front sets up a lot of stresses in the system. I tried to dry assemble the units for my geodesic dome on the workshop floor, and wasn't able to get up beyond where the sections go flat. Everything wanted to tilt toward the door.

[toddj]

Re: Todd's Oven

You guys set the bar pretty high lol... I feel like a space monkey..

Ok well SO FAR everything fits together tight enough to do it so I will keep going and see what happens.. I will need to mortar my arch and chimney for safety but the dome will go old school gravity... with a liberal coat of heat stop on the outside..

is there any fiber additive i can add to the heat stop mix to make it bind better as a coating... kevlar fiber? any ideas??