dmun's 36" geodesic oven part II

[dmun]

Re: dmun's 36" geodesic oven part II

Those chimney blocks were heavy. There was no way for one person to carry them up a ladder, and no room for two.



Here's a winch, improvised from a big winding barrel from my tower clock. There's a pulley mounted at the top of the tower, and another one on the clamp jig, to compound it once. A direct lift was possible with the flue tile shown here, but not the chimney block.



Here's a chimney block on the way up. Every other block got one side cut off, to avoid a running seam going up the chimney, so there were only three full blocks to lift. Three were enough. Even the cut ones were super-heavy.



Swinging sideways into position.

[dmun]

Re: dmun's 36" geodesic oven part II

I decided that the sill plate at the top of the block wall shouldn't be cut, for reasons of the structural stability of the studio.



This means that that it goes through the chimney, and needs two inches of airspace and four inches of masonry between it and the flues. A concrete slug will be formed and poured around the space around the 2x8.



Another construction detail: since the fireplace chimney goes up at an eight degree angle it will get unstable after a while (remember, the flue tiles are supposed to be free-standing). Here is a block of insblock19 used as a slip plane for the flue to lean on. I used three of these in the length of the run. Here, the lower flue tile is mortared, and ready for the placement of the next tile. See that shiny stuff at the bottom of the flue? I put a layer of bubble wrap over the damper, so falling mortar wouldn't glue my damper shut.



Onward,



and upward. Ready for the chimney block run, you can see one at my feet.

[dmun]

Re: dmun's 36" geodesic oven part II

The refractory flue tiles, particularly the eight by twelve ones, are really heavy and awkward to handle.



Here's a couple of c-clamps pressed into service (with plywood cushons) for use as handles. Remember, you have to drop the down from above, often into a pre-built concrete hole.



In position.



Mortared in, and blocked to the height of the oven bridge.



After the refractory mortar had set for a day, I could use the top of the flue as a work position for the mortar tub. Space is really tight in the tower, and is going to get tighter as I go up.

[dmun]

Re: dmun's 36" geodesic oven part II

Ok, I've been behind schedule on posting the progress with my oven, so here are a bunch of pictures to keep you informed about the progress of my chimney.



When I was last documenting my masonry work, the oven and the fireplace were both walled up to the tops of the smoke chambers, and the support bridge for the chimney had been poured over the oven. Now I start building the flue and it's surrounding block structure up from the fireplace to get them to the same level.



This part of the chimney goes up through a slot cut in the wallboard.



After some thought, I decided to tilt the fireplace flue eight degrees back, the plan being for the two flues to converge at the required five inches apart at the top of the tower. This required two eight degree cuts on every block level, and there are a lot of them.



The bricky system contains a jig to mortar the ends of four inch blocks. Unfortunatly the flue is in too confined a space to use the big bricky for the horizontal joints.

[jwnorris]

Re: dmun's 36" geodesic oven part II

<snip> Well done.
Jim

Well done, indeed.

J W

[CanuckJim]

Re: dmun's 36&quot; geodesic oven part II

Dmun,

I haven't said much in response to your magesterial log of the build, but I think I speak for many members here when I say that your long term vision and execution of what you see is truly marvelous. Congratulations.

And, no, living in an 1856 balloon frame house with mortises and tenons everywhere and material dimensions we can only dream about, I cannot understand how those guys did that. I have white pine interior panelling that's 22 inches wide and twenty feet long without a knot in sight; all hand planed. Cripes, makes my arms ache just thinking about it.

There are hip roofs all around me of the same period. They did not have multi-ply, thin wood for the curves, yet they are still standing. Amazing when you think about it.

Just cast your mind back to punching that first, rather tentative, hole in the wall. Well done.

Jim

[dmun]

Re: dmun's 36&quot; geodesic oven part II

I especially like the curved lines of your roof. I am currently grappling with my very simple hip roof design and am stretched to my maximum abilities.

Hip roofs are hard, and the curve is just icing on the cake. The real work is the hip roof it's self. You have to admire the Victorians, who built riots of elaborate rooflines with no more than a framing square and a plumb bob. Can you imagine working without a retractable tape measure, let alone a CAD program?

[swripley]

Re: dmun's 36&quot; geodesic oven part II

David,

Wow! Beautiful build. I especially like the curved lines of your roof. I am currently grappling with my very simple hip roof design and am stretched to my maximum abilities. Your's makes me feel like a slug!

Sharon

[dmun]

Re: dmun's 36&quot; geodesic oven part II

Since you can't leave insulation exposed (the vapor barrier is combustible) I then move on to a job that I don't think anyone in America has done since 1962 - installing knotty pine paneling. In the flood this spring, a neighbor tore out the basement rec-room from that date, and left a huge pile of 3/4 inch milled knotty pine paneling. I thought it would make a neat interior finish to the tower.



You remember those round shaftways going through the masonry part of the oven? They continue up through the tower, as vee shaped recesses in the thick side walls. Here's the one on the left:



Here's a lower view, showing the (temporarily) covered shaftway. This side, which will be two inches away from the chimney, needed everything combustible flush with the surface of the paneling, to maintain the two inches to combustibles.



An overall view.

An upward view, without flash, showing how the clearestory window will illuminate the tower:



It's all well and good to use recycled lumber, but it's a lot of work. The knotty pine paneling is blind nailed, and held together by tongues and grooves. A lot of those were damaged when the walling was ripped out, so I had to pick and choose which pieces to use where it was most visible.

[dmun]

Re: dmun's 36&quot; geodesic oven part II

Well, it's high summer, and one can see the advantage of moving the construction inside where it's air-conditioned,



but the problem is that heat rises, and the interior of the tower tends to be a sweat-box, even with the AC on.

The first interior job is doing the insulation. It's a miserable job in the heat, but of course one never does it when it's cold.





That hole in the side, is an exterior access port for the shaftway, which will be covered by the chimney.

[Hendo]

Re: dmun's 36&quot; geodesic oven part II

David,

The tower is looking great. I can just picture the roof clad in colourful tiles like they use in Burgundy. Very grand!

Cheers, Paul.

[dmun]

Re: dmun's 36&quot; geodesic oven part II

At least I don't have to worry about wood for my seasoning fires. I have a mound of scraps and leftovers. You want to see something burn? Try cedar shingles. Whew.

[Unofornaio]

Re: dmun's 36&quot; geodesic oven part II

this build has really caught my attention and I'm looking forward to its completion (as I'm sure you are) its really looking great.
I had to reply (other than to complement you) on the very first photo of you on the patio. It reminded me of when I first built my backyard oven years ago. After it was done I just didn't look at "wood" in the same way, Id be on a job and looking at the scrap wood thinking..hmmmm I wonder how that will burn..and If I knew how to do it I would have re-posted that picture of you with the caption "I wonder how that wood will burn?"
Anyway my sense of humor is kinda twisted so if you don't think its funny sorry for any offense.

[dmun]

Re: dmun's 36&quot; geodesic oven part II

Laying out the roof sheething from a grid, from the CAD drawing. Once I cut one out, i used it as a model to cut out the others. That was the technique I used for the curved rafters as well:



The roof sheething pieces ready:



In case you were wondering, (I was), the sheething does bend to the curve:



A view from the top of the masonry layer, up the now enclosed tower:

[dmun]

Re: dmun's 36&quot; geodesic oven part II

Another view:



From the rear:



From the front:



From the house, the roof peeks over the front studio roof, just above facia level. Here's the view from the second floor of the house: