36" build in Tallahassee - AKA Bruce's Folly

[Bec1208]

Re: 36" build in Tallahassee - AKA Bruce's Folly

Gudday Bruce
Now that looks better and better everyday. I can almost smell the bread baking!
I noticed that you have a thermal break between the entranceway and dome and its full of insulation. That's good but the bare surface of the insulation not so good . Those fibres have to be sealed in you can't leave them open to the air. You can fill with a piece of metal tube or channel but that could be hard to shape and get the correct dimension. You also could fill with a pearlite cement mix ...Anyway that's your thoughts on it ...has anyone else any ideas

Hi Dave,

If you look closely at the image below you can see the exposed insulation is actually an 1/8" thick woven fiberglass seal. My initial idea was to apply a coating of the refractory mortar to seal it off, but I will wait a few days and see what other ideas emerge.

Whilst I asking what are you finishing the dome with ( notice I didn't us the term plan either)
Regards dave

Dave, you certainly have me pegged. You're right, I don't have a scheme, program, or method worked out beforehand for the accomplishment of completing the oven. I plan (there I said it) to start curing the oven per your previous suggestion and round out the dome. I will stucco the dome and waterproof adding a vent to the top. Eventually I would like to get some kind of roof over it. Remain open to suggestions. Thanks again, bruce

[Bec1208]

Re: 36" build in Tallahassee - AKA Bruce's Folly

Gudday Bruce
Thinking about it .... What product did you use when you " keyed" you base together? Would this be suitable to render over your insulation on the dome?
Regards dave

I used quickrete surface bonding cement. It is reinforced with fiberglass and I believe can be used for render. It appears to be pretty tough stuff once it cures.

[Bec1208]

Re: 36" build in Tallahassee - AKA Bruce's Folly

I had a small fire going through most of yesterday. Temps ranged from about 200 to 250. Smoke drew through the smoke chamber nicely. I also worked on rounding the dome. Is there anything else I need to do to prepare for stucco? Any comments appreciated.

[deejayoh]

Re: 36" build in Tallahassee - AKA Bruce's Folly

Personally, I would'nt go any further until you address the insulation showing at the back of the entry arch. You don't want those nasty fibers getting anywhere near anything you are going to eat.

You could peel back the insulation around the entry arch where it is showing, and apply some mortar from the outside of the oven to fill that gap. Give it a good coating so that the mortar has a "T" shape fill in the gap, with the wide part on the outside - and the bottom leg protrudes through the gap. Then cut off the snots on the inside. If you try to fill it from the inside, I fear it is just going to fall out when you fire the oven as the mortar shrinks and has nothing to stick to.

If you are using it for a heat break, then it seems a bit wide and the insulation seems too directly exposed

[Bec1208]

Re: 36" build in Tallahassee - AKA Bruce's Folly

Personally, I would'nt go any further until you address the insulation showing at the back of the entry arch. You don't want those nasty fibers getting anywhere near anything you are going to eat.

You could peel back the insulation around the entry arch where it is showing, and apply some mortar from the outside of the oven to fill that gap. Give it a good coating so that the mortar has a "T" shape fill in the gap, with the wide part on the outside - and the bottom leg protrudes through the gap. Then cut off the snots on the inside. If you try to fill it from the inside, I fear it is just going to fall out when you fire the oven as the mortar shrinks and has nothing to stick to.

If you are using it for a heat break, then it seems a bit wide and the insulation seems too directly exposed

Thanks, what about using vermiculite or perlite concrete to fill per Dave's suggestion?

[stonecutter]

Re: 36" build in Tallahassee - AKA Bruce's Folly

If it was me, I would make a small sheet metal panel (SS or Aluminum), put a 90* or little less bend on the side touching the oven arch for friction, other side of the panel would slide behind your outer arch...covering your insulation. A parge of any type of material will fail.

[stonecutter]

Re: 36" build in Tallahassee - AKA Bruce's Folly

If you are using it for a heat break, then it seems a bit wide and the insulation seems too directly exposed

DJ, the insulation is showing because the oven arch and the outer arch spring from different points. The outer arch springs from the floor lever while the oven arch springs 8" above it. No avoiding what happened here, unless he tore the oven arch down and laid the lower part as stretchers instead of headers.

[Gulf]

Re: 36" build in Tallahassee - AKA Bruce's Folly

Bruce,
It looks to me like you could add brick laterally to make the face of your inner arch wider. That would close up the gap narrow enough to seal the fibers with a food safe gasket sealer putty. I don't remember what it is called. I think Russell and a few others used it on their heat breaks.

[deejayoh]

Re: 36" build in Tallahassee - AKA Bruce's Folly

DJ, the insulation is showing because the oven arch and the outer arch spring from different points. The outer arch springs from the floor lever while the oven arch springs 8" above it. No avoiding what happened here, unless he tore the oven arch down and laid the lower part as stretchers instead of headers.

Your assessment is for sure better than mine on this one, I can't really tell from the pics. Just seems like something to figure out before it's all covered up with concrete and stucco.

Tough part with a metal cover would be getting it to fit right. Seems like some combo of brick + mortar would be more forgiving, but I take your point about the two arches having different shapes.

[stonecutter]

Re: 36" build in Tallahassee - AKA Bruce's Folly

I'm thinking that he should be able to slide the panel from the inside with no trouble.

The problem with using masory in that small area is there is nowhere to tie in....there's going to be running joints.

[Gulf]

Re: 36" build in Tallahassee - AKA Bruce's Folly

I agree with you Stonecutter. But, I think that once the two faces are closed up to the proper gap size, (filled with the insulation, and sealed)they will help to hold the brick fragments in place should the mortar fail. Like you, I also think that Bruce could "slide the panel from the inside with no trouble"...... later, if needed .

just say'n

[deejayoh]

Re: 36" build in Tallahassee - AKA Bruce's Folly

I'm thinking that he should be able to slide the panel from the inside with no trouble.

The problem with using masory in that small area is there is nowhere to tie in....there's going to be running joints.

I had to re-read what you suggested. I get what you are saying now. Piece of flat steel bent like angle iron, slide it into the back of the gap so that the hidden leg is against the dome, and the exposed leg covers the insulation.

If I get what you're suggesting, Bruce could make it long enough to go all the way around the arch - make some cuts in the back so that he can make it conform to the arch and let the tension hold it in.

[stonecutter]

Re: 36" build in Tallahassee - AKA Bruce's Folly

Yes...that's it. A little tricky, but at least it will hold up and do the job. I think it will be easier for Bruce too, since it can be fabricated on the bench, checked for fit and adjusted, whereas unit masonry has to be built in situ.


Thinking about it some more, if one of the bends faced the oven arch, and another bend faced the back of the outer arch, that would add good tension to the plate.

[deejayoh]

Re: 36" build in Tallahassee - AKA Bruce's Folly

That would work. He could also put a couple stainless tapcons through the metal into the entry arch brick somewhere to hold it. The stainless ones are a bit hard to come by, but they will hold in firebrick if you don't torque 'em in to hard.

[cobblerdave]

Re: 36" build in Tallahassee - AKA Bruce's Folly

Gudday guys
Well this is working well ! Team problem solving seems a more friendly and productive process. I'm sure the sniping will not stop,its a forum, but treated with indifference that such comments deserve it won't make a difference
Regards dave