Starting new 36" build

[Amac]

Re: Starting new 36" build

Are you using a "lazy susan" type design for the IT to achieve the flattened top?
I think with the lazy susan IT the flattening happens naturally as you get higher up depending I guess on the offset of the pivot.

I am going with an elipse shape for the dome - 18" height - so I am hoping the cut will be right. I expect I will have to do some trimming as I go up.

Ideally the slope where the dome wall meets the arch will be exactly the thickness of the dome wall (1/2 a brick), so the inner edge should coincide with the inner radius as measured by the IT, and the outer edge with the outer radius.
With those straight sided arches I am not sure that can be achieved for the rounded part.

..and I am headed to Whistler for the weekend anyway!

I guess that means skiing - enjoy the slopes and don't forget a pint of green beer for paddy's day
regards
Aidan

[deejayoh]

Re: Starting new 36" build

Aidan -
I am going with an elipse shape for the dome - 18" height - so I am hoping the cut will be right. I expect I will have to do some trimming as I go up.

As I said, I am not planning to mortar them all into place until I get the dome up higher. I'm also planning to use my IT (once I build it...) to check all the clearances

Probably won't happen for a couple weeks - as we've got cold temps and rain forecast for the next week, and I am headed to Whistler for the weekend anyway!

[Amac]

Re: Starting new 36" build

btw DJO - on the arch geometry - it's hard to comment without knowing exactly what radius you chose for the arch curve. Maybe I missed it somewhere. The rounded part all look like the same cut from the pics (maybe not) but I would have thought that unless you go for a semicircular arch like I did, you will have trouble getting it to fit the dome as it goes up. You know this problem that the bricks need to "reach" back in which would make the arch bricks at the top appear to protrude more than the lower ones. With the bigger radius that might not be much of a problem?

I thought that Gianni had said that he would have cut the arch bricks as he arrived at them. Maybe John if you are reading you could clarify that!

[david s]

Re: Starting new 36" build

It is a good idea to have some wooden wedges under the arch form so when you remove them it will drop 1/2" or so for easier removal. From the look of your pic you are going to have a hard time removing those bricks under it the way it is set up now. You don't want to upset your brick arch once it's laid.

[deejayoh]

Re: Starting new 36" build

In Kens vent is the opening for the flue just 4.5 ". Is there a good reason not to bite off a bit more than half a brick - or does it matter?
Aidan

Good point.

I'll probably make it 5" x 10" - giving me 50" of space - which is the same as the area of the flue I am using. Maybe 5 x 11 just to be safe!

His posts indicate that the oven draws well, and it is a 42" - so I think a 39" should be fine with the same design.

[Amac]

Re: Starting new 36" build

Looks brilliant so far DJO - very tight cuts - looks like you won't need any mortar at all In Kens vent is the opening for the flue just 4.5 ". Is there a good reason not to bite off a bit more than half a brick - or does it matter?
Aidan

[deejayoh]

Re: Starting new 36" build

Yes you can. IMO it is worth the effort to make the entry as shallow as you can, which makes the oven easier to work.

Thanks for the reassurance. I did some more investigating and it looks like Ken solved this on his "Kentucky dome". I'm planning to work off of his design. I will probably use refractory cement for the final mounting of the anchor plate instead of mortar - but the basic design seems like it should work.

http://www.fornobravo.com/forum/21/m...html#post19105

[deejayoh]

Re: Starting new 36" build

Well, good progress to report this weekend. Both days were rainy, blustery, and cold - and as I probably don't need to tell most of you, working with that tile saw leads to some pretty cold hands! But I persevered between trips inside to warm myself - and ended up getting the bricks all cut for the first three courses and the arch.

I'm going to try to follow John's (Gianni) approach on the arch - where you cut the back to conform to the dome - so am planning to leave those un-mortared until I get the rings going. Actually, for now the whole thing is unmortared - because I can't seem to find cement and lime in bags less than 100lbs, and also can't find anything but sandbox sand. Anyone have any guidance on where I might find 50lb bags, and fine sand?

Oh, and I am producing a whole mess-o-fireclay. I didn't really believe it when people said you really don't need to buy fire clay - and now I have an 80lb bag of it and am finding it in my water tray by the bucket load! Newbies take note, learn from my mistake!

Other than that, I am feeling pretty good about the progress. Take a look at my arch geometry and tell me what you think. The "corner" pieces are not final in the picture I posted - but I have finished those too. Ended up using 3 bricks turned on their side to get just the right height/angle. It involved some pretty intricate cutting. I'll try to post a shot of that later.

Pictures are attached. I finally figured out the thumbnail thing!

[david s]

Re: Starting new 36" build

Yes you can. IMO it is worth the effort to make the entry as shallow as you can, which makes the oven easier to work.

[deejayoh]

Re: Starting new 36" build

I have been working on the design for the vent/landing - and I just realized that I may have an issue. I was planning on a 9" landing - basically the length of a single fire brick. But I bought (and am planning to use) an 8" duravent anchorplate - which I now see is going to be tough to fit on top of a 9" long vent arch as it has 12 x 12 footprint

Kind of crazy because the FB plans call for a 8-9" vent, and the use of an 8" flue - so how is this all sposta fit? Am I missing something?

Can you have a narrower, longer slot in top of the vent (say something like 5x10= 50" area) that feeds into an 8" round flue (which is also about 50" area)? Will that work?

What have others done/planned?

[Amac]

Re: Starting new 36" build

You're a neat worker djo - this'll be a good one. Keep it going. The building process is a lot more fun than I expected - enjoy it - it's magic!
Aidan

[GianniFocaccia]

Re: Starting new 36" build

Great start, DJO. Dr Seward's build has to be one of the tops for build quality and design.
Keep the pics coming.
John

[deejayoh]

Re: Starting new 36" build

Lots of progress today! Picked up the final layer of floor insulation last Thursday.

Today I laid the floor insulation, cut the bricks for the floor, and got about 1 and 1/4 courses of "sailors" cut

I am planning to lay 3 vertical sailor courses, and then start angling the dome. I am going to build an elliptical dome like Dr Sewards, so will be using an off-center IT that rotates on plywood lazy susan to get the angles all correct and have a flat plug.

Here are some updated pix + a shot of parts for my super-cheap IT, inspired by Cheesteak!

[GianniFocaccia]

Re: Starting new 36" build

I am going to get 1 inch to supplement the 2" of FB board I already have

Sweet. You're gonna love the heat retention and slower oven coast.

[deejayoh]

Re: Starting new 36" build

Finally got the hearth poured, so I am finished with this phase of work.

Since the back half of the hearth is "on grade", I used a concrete additive called Xypex Admix C-1000 to waterproof the concrete and keep moisture out of my oven. It is supposed to create a crystalline structure inside the concrete that blocks the capillary action. It's typically used in swimming pools, sewage plants, and other high water situations. Hoping it will do the trick for me.

Picking up my bricks on Saturday morning!


Gianni -
thanks for the info on the board. I am going to get 1 inch to supplement the 2" of FB board I already have. That will put me at 46.5" opening height, which I think is perfect.