32 Igloo Build, Lakeway TX

[pfennigthecat]

Re: 32 Igloo Build, Lakeway TX

I think it's just forced perspective from the camera angle or something. From memory, it's like 10" of counter and 11" of oven landing bricks then the circle -- tanding in front of it I don't think there will be a problem. But yes, I will be using a long-handled peel.

[mrchipster]

Re: 32 Igloo Build, Lakeway TX

That's not bad it looks a lot further in the picture for some reason.

Chip

[pfennigthecat]

Re: 32 Igloo Build, Lakeway TX

Counters are in and feeling indestructible. 2.5" of reinforced concrete just feels more secure than 2.5" of solid granite would have been. I wont' worry about jumping all over this thing to build the dome.

[FrankT]

Re: 32 Igloo Build, Lakeway TX

Keep up the hard work, your oven will reward you.


Great build!

[miltcook]

Re: 32 Igloo Build, Lakeway TX

Counters are in and feeling indestructible. 2.5" of reinforced concrete just feels more secure than 2.5" of solid granite would have been. I wont' worry about jumping all over this thing to build the dome.

Newby question here, because I'm just in the planning stages, but since the floor firebricks directly touch the concrete countertop, won't that be one big heat sink? I don't see an insulation there. I like the look, but would be worried about the heat on the countertop.

Milt

[pfennigthecat]

Re: 32 Igloo Build, Lakeway TX

Miltcook, if you check the posts from June 1 in this thread, you'll see that I wanted to avoid the floor firebricks directly touching the concrete countertops, so I made a form that leaves about 3.5" between the counters and the oven proper -- they're both on top of the vermiculite layer but not touching each other. Once the dome is complete this gap will be filled by ceramic blanket and more vermicrete over the oven.

Edit: if you were talking about the contact between the oven landing bricks and the concrete counters, yes they do touch and there will be some thermal leakage there. There is a small (~1/8") break between the 'real' oven floor bricks and the bricks under the entry arch to mitigate this. When the door is pressed against the oven, it will be right on top of this gap, which will fill with ash. I wouldn't go putting my hand on the bricks in the entryway, but hopefully this will be enough to make the counters themselves safe. There have been some other threads around designing thermal breaks at the oven opening, but common consensus seems to be that they are overkill. You can cook for days even without them.


Work has kept me away from the oven for the last month, but yesterday I finally went vertical: i has arch!
17" wide by 11" tall, ~63" of the final ~17" dome interior height.
Backs of the arch tapered to approximately match the dome angle at the point of intersection.
This is the 'interior' arch, which won't be seen from the outside (it will be completely covered with blanket and vermicrete and stucco). For the outside arch I will be more careful with the cutting of the corner pieces

[pfennigthecat]

Re: 32 Igloo Build, Lakeway TX

Been making slow progress -- one chain per weekend usually (though I got two this weekend. Things I've learned:

- Homebrew mortar mix was a good idea so far (3:1:1;1 sand:cement:lime:fireclay).
- I get better with each chain (as you can see from the photo, ).
- A simple Tilt and Turn jig on the wet saw works really well, but I wasn't able to use the spreadsheet well -- I always ended up just eyeballing the first couple bricks and cutting a few times till they held in place properly, then cutting the rest of the bricks for the chain the same way. Easier to just prop with different thicknesses of scrap than to actually measure angles.
- Angling the inside face of the arch bricks worked out very well -- no really odd cuts to make so far. The next chain might prove problematic though as the arch is I think slightly higher than chain #5. Shaving the bricks might be hard. It's the opposite problem to the dreaded droop others have I think.

[pfennigthecat]

Re: 32 Igloo Build, Lakeway TX

I am (I think) within dome-closing distance -- one more chain then a plug ought to do it.

I started having problems with bricks sliding inwards about 3 chains ago. The solution for me, which I hadn't seen elsewhere was to use a 'lock stone'. Think of it as the opposite of a key stone:
- A key stone locks the whole chain by being the last brick in place -- once it's in place, the whole chain can't slip inwards because they push against each other.
- A lock stone means after completing one chain, I immediately place the first brick (or 2) of the next chain. The IT supports this brick while it sets, so that the next day I can set the rest of the bricks in the chain and have something immovable to lock against until I complete the whole chain and place the key stone.

This has worked well for me so far -- no slippage, no need for extra support mechanisms.



I need to get a bit more fireclay and sand for mortar mix before I continue, but going well. I'm getting better at this as I go along of course -- now that I'm getting close to completion . At least I'll be reasonably good with the mortaring for my exposed exterior arch.

Looking into getting blanket and chimney soon. Blanket is pretty straight forward, but not sure on exactly what kind of duravent to get yet. Consensus seemes to be 8" duravent is best, but would 6" be just as good if my chimney is particularly tall? I.e. does taller == draws better? My Chimney is likely to be about 7' tall to make sure i'm 2' higher than any nearby rooflines.

[boerwarrior]

Re: 32 Igloo Build, Lakeway TX

Pfennig (hah - that's German for "penny"!)

I have a 32 inch oven and I have a six foot Duravent Stainless Steel 6" chimney. I also used a 6 inch SS vent plate and a 6" SS Chimney cap.

My chimney draws extremely well. I also considered using an 8 inch chimney but I am glad I didn't. I don't think I would have gained anything.

You can see my chimney installation pictures starting at post #84 in my thread:

http://www.fornobravo.com/forum/8/32...a-19283-9.html

[pfennigthecat]

Re: 32 Igloo Build, Lakeway TX

Meine deutch ist nicht sehr gut, aber ya pfennig ist 'penny' :-)

I've ordered 6" ID Selkirk MetalBest stainless (inner and outer) pipe for my vent, along with anchor plate and cap. It was a bit cheaper than I could find for duratech and seemed just as good. hopefully will close the dome and build outer arch this weekend and then be able to start curing fires while ordering and waiting for ceramic blanket.

Cracks, here I come!

[mrchipster]

Re: 32 Igloo Build, Lakeway TX

I am (I think) within dome-closing distance -- one more chain then a plug ought to do it.

I started having problems with bricks sliding inwards about 3 chains ago. The solution for me, which I hadn't seen elsewhere was to use a 'lock stone'. Think of it as the opposite of a key stone:
- A key stone locks the whole chain by being the last brick in place -- once it's in place, the whole chain can't slip inwards because they push against each other.
- A lock stone means after completing one chain, I immediately place the first brick (or 2) of the next chain. The IT supports this brick while it sets, so that the next day I can set the rest of the bricks in the chain and have something immovable to lock against until I complete the whole chain and place the key stone.

This has worked well for me so far -- no slippage, no need for extra support mechanisms.


.

I like the term lock stone but "lock brick" is even more descriptive in this case. In either case it is good to put a name to it. That technique worked well for me.

[oasiscdm]

Re: 32 Igloo Build, Lakeway TX

And you need to let it set. Thought I would be smart and do this, go to hardware store, come back and lay next brick and guess what. The pressure dislodged the key brick. Motto, leave overnight is a must so it dries properly

[Tscarborough]

Re: 32 Igloo Build, Lakeway TX

Either your mortar or your brick are too wet. Proper mortar should grab almost instantly as the moisture is absorbed out of the mortar into the brick. You should not need to use anything to hold the brick up at all.

[mrchipster]

Re: 32 Igloo Build, Lakeway TX

Either your mortar or your brick are too wet. Proper mortar should grab almost instantly as the moisture is absorbed out of the mortar into the brick. You should not need to use anything to hold the brick up at all.

For the majority of us this is the first time we ever laid a brick and the first hundred or so on the oven are quite easy for even the novice, then they start to tip in it is a whole different game and the technique of leaving a brick sit over night really helps those of us who otherwise would be throwing bricks through windows in frustration over not being able to get the second brick to hold against the first without starting over.

Unfortunately we do not know how to "read" wet mortar vs dry and are trying to just get the brick in the right place at the right angle at the right distance from the previous brick and still keep our sanity.

[pfennigthecat]

Re: 32 Igloo Build, Lakeway TX

Exactly what Chip said -- this is my first attempt at masonry .

Especially with TX being so hot and dry, and it being summer, I probably have been keeping my bricks too wet -- I soak them in a plastic tub after cutting them, watch them bubble! I don't take them directly from the tub and butter the mortar onto them, but they only sit out for about 10 mins before I start laying.

Even so, I haven't actually had _major_ problems with bricks falling out of place, but the lock brick / lock stone approach still helped a lot, mostly with my confidence.


I put in the dome plug brick today!!!!! WOOOOOOOOOOOOO!

After getting it just the right shape, I carved a cat into the bottom so you could see it if.... um... you were in the fire???? Oh, a mirror, smart......

I also completed the decorative arch this weekend --- vertical sides and buttresses yesterday, the arch itself (with hole for chimney) today. Will post pics later once I trust it enough to take the wood form out -- right now it's covered in damp towels to keep it from drying too fast.