dmun's 36" geodesic oven Pompeii Oven Construction Discuss dmun's 36" geodesic oven in the Pizza Oven Design and Installation forums; Jengineer, I agree wholeheartedly that a subfolder for Dmun's most amazing, complex, perfect, geometric, historical project would be very worthwhile. ...

[CanuckJim]

Jengineer,

I agree wholeheartedly that a subfolder for Dmun's most amazing, complex, perfect, geometric, historical project would be very worthwhile. It could, perhaps, be titled The Brick Saw Primer. Dmun, your work is superior.

Jim

[dmun]

I've sometimes felt bad about monopolizing the pompeii thread, particularly when it steps on the postings of someone who's building an actual pompeii.

There might be a place for a "Geodesic oven" category, but until there's more than one, (and I remind you, there isn't even one yet) that might be premature.

I'll defer to James in all this.

[maver]

I think the argument to sticky your work and break up your thread would be to make it easier to find e.g. the Rumford portion of your work and because you have done some things with technique that are very well documented and demonstrated with photos - there's a lot in your brickwork pictures that can help other oven builders (all this before even beginning dome construction - I can hardly wait to see that).

On the flip side, it would be a chore to divide your thread - we can rely on the search feature of the forum. I would say just keep doing what you are doing. I appreciate seeing your work. I wish I had 1/4 your planning and patience with the project.

[CAM]

I don't know where it should fit in, but it definitely fits in and I look forward to seeing and encourage the posting of many more pictures with commentary.
If I ever finish building my house I will start my oven and agree that seeing the work and ideas of others is invaluable. Keep it up DMUN.

[dmun]

The building that I'm putting the oven/fireplace into was built as a cinder block garage in the twenties of the last century.


An exploratory bashing the previous week showed that this would be no picnic. Even with a sledgehammer, it comes off chip by chip.



After a day of less than fun hammering, I got a big hole in the side of the building. The good news is that the overhead row of blocks didn't collapse despite an old settling crack, that runs the entire height of the wall.

[dmun]

It was my hope to save enough old rusticated blocks to patch the window opening.



Here's what I ended up with, one badly battered whole block and a lot of crumbs. Those blocks are about twice as heavy as the modern ones. No wonder they are hard to bust up.



An inside view.



New sonotubes are alligned with the old ones using building paper. This is to prepare for filling the brick piers with concrete, and casting the slab.

[dmun]

I burried the rebar in concrete filled block holes on the inside, and in the filled brick piers on the outside. My plan was to use the bend-with-pipe method of tying the slab to the base.





The rebar bent fine, but only to about ten degrees off horizontal. Hammering wasn't effective to get them flatter.



I finally tied them down with another piece of rebar, connected to threaded loops to tie them to the concrete form. This tended to lift the form, so I put a concrete block on it temporarily until the first couple of loads of concrete put some weight on it.

[dmun]

I filled the cavities on the inside that weren't filled with insulating concrete with used fiberglass insulation, with the combustible paper backing peeled off. I closed the top of these holes with pieces of slate.



The form on the inside was braced against the framing on the sides, and against a workbench leg in the front.



After pouring and floating the slab, it was pretty wet on top. I placed the insulation board, Insblock 19, from Kraemer Gunnite (thanks guys) in Southern Jersey, directly on top of the wet concrete to adhere it.



So there it was, a weekend of hard work, and a couple of jobs that I had frankly been dreading.

[maver]

This looks ridiculously good. You actually used a sledge to knock through that concrete block? You've really got me thinking that I should make a Rumford with a form for my outside fireplace just like yours, although I don't think I have the precision or patience - I'm going to look into buying a throat rather than doing the BIA.

Now you get to put the dome together - it'll be as easy as legos, vero?

[CanuckJim]

Dmun,

A bit late to the fray, but you might have been able to salvage more of the old blocks by renting a large Hilti or Bosche hammer drill, with a suitably sized bit. Then, you could have drilled out the mortar and pushed the blocks out, or at least as many as you needed. Although your line of block appears to be holding, I suggest that you put in some sort of header, like a flat piece of iron to span the gap, just to be on the safe side. You could drill out the mortar on each side and remortar it in place.

Work like this is just great for the back, ain't it.

Jim