Oven on wheels

[wotavidone]

Re: Oven on wheels

Got another ring of bricks on. More after dark photos, unfortunately.
Two or three bricks aren't as aligned as I'd like. I may re-do those tomorrow.
I now only have a 30cm circle to fill.

[Bacterium]

Re: Oven on wheels

Wow now that's what you call a "double soldier" course......gotta be proud of that.

[wotavidone]

Re: Oven on wheels

Hey Damon.
I was just about to finally confess I had no idea what the heck a "soldier course" is, when I chanced to read Dave's last post on your 2nd build thread. So. I've got a ring of vertical bricks surrounding my cooking floor. This is a soldier course? I wasn't quite sure. It appears its not the conventional way to do it these days, but I'm reasonably hopeful that by the time I add the inch of render over the outside of the whole dome, it'll all be stable enough to withstand heating and cooling. It probably looks wrong too, from the point of view of going down to the concrete slab, but my slab is made with scoria. According to the academic paper I got the mix from, it has a slightly better insulating value than vermicrete made 3:2:1 with vermiculite sand and cement.
By the time I add the render, it'll be 3 inches thick, with a 2 inch thick cooking floor. This seems to fit with the ratios of thermal mass that FB uses in their ovens, so I reckon it'll work. Its not raining this morning, so today is "close the dome" day.

[brickie in oz]

Re: Oven on wheels

Its actually a sailor course.

[Bacterium]

Re: Oven on wheels

......ahhh I get it (just did wiki) soldier and sailor are BOTH vertical terms

So does that mean when you shoot a sailor/soldier he ly down so out comes the stretcher

[wotavidone]

Re: Oven on wheels

Ah! I just wiki'd it too. I see it is meant to only be decorative. OOPS! Ah well, I'm not trying to hold up a two story building with it.

[cobblerdave]

Re: Oven on wheels

Gudday
I'm not a trendy either I've got an out of date oven ...its got a soldier course.
Point is that more ovens now tend to get built with the first course on the hearth itself. The soldier course was popular because it allowed you suposedly to replace any cracked hearth stone easily...guess what no one seems to need to do this. Easy method.... makes the cuts on the hearth edge easy as they don't need to be super accurate. First layer of bricks are then layed on there sides so there aren't as tall and possibly not as prone to sidward thrust.

Regards Dave

[david s]

Re: Oven on wheels

I always thought the idea of having the first course vertical was to allow you to have things in the oven right up to the wal to maximize floor area. To my mind running bricks vertically is encouraging cracks as they tend to always run vertically from the bottom.

[wotavidone]

Re: Oven on wheels

To my mind running bricks vertically is encouraging cracks as they tend to always run vertically from the bottom.

Oh dear. Despite reading lots on this forum, I didn't absorb that bit. Then I laid the sailor course thinking I was going to make the rest of the dome as a one piece casting. I changed my mind and kept going in brick, but I now realise that laying them thin edge to thin edge wasn't smart, its probably too thin for strength. This is the downside of changing your mind halfway through. I believe I will clad the dome in mortar/concrete before firing it, to try to improve the strength. I believe that I will sleep better if the cladding has reinforcing in it, too. Still pondering all that.

[david s]

Re: Oven on wheels

I think you'll be fine. I really like the simplicity of your build. I agree with the idea of some reinforced cladding. Go for it. If it were mine I think I'd go for home brew with stainless steel (melt extract fibres) reinforcing.

How thick are your walls now?

[wotavidone]

Re: Oven on wheels

At the moment its 2 inches, the thickness of the bricks.
Where do I get melt extract fibres in South Oz?
Its only a small dome, outer diameter at present would be 850 mm, so I'm thinking a 1 inch render coat isn't a lot of material. I sorta like the idea actually-it'd be the equivalent of a cast dome "tiled" inside with fired brick.

[david s]

Re: Oven on wheels

Yeah I think 1" would be good. I get my SS fibres from Antec Engineering, Sydney, but you might get them in Adelaide. Add at least 2% by weight.

[wotavidone]

Re: Oven on wheels

I just have to stick the plug in tomorrow.
I'm going to leave it over night, then extract the centre post by heating the thing with my paint stripping gun until it collapses.

[cobblerdave]

Re: Oven on wheels

Gudday Mick
glad to be the first to say....well done THAT looks damn good ... betcha pretty pleased... as you should

Regards Dave

[wotavidone]

Re: Oven on wheels

Thanks for the kind words Dave. I must admit your encouragement kept me going when I might given it away as a bad joke. I did my best to keep the mortar exposed to the flames as thin as possible, but looking at the up and under shot, I failed in a couple of spots. Cutting tapers isn't as straightforward as it seems.
I'm afraid it now has to go down the priority list for a while. Back to work Monday, have to go see my gunsmith today or tomorrow, got family stuff to do, etc.
I will make three test batches of reinforced mortar/render today or tomorrow. In the process of searching out the preferred stainless needles, but in the meantime I'll test mortar and chicken wire.
One will be a standard sand cement and lime mix, one will be sand cement lime, and my wild clay. The last will be the same with purchased terracotta clay.
I have plenty leftover bricks to experiment with.
I have decided on an easy insulation job. I figured I can simply enclose the whole oven except the arch in a corrugated iron box, and poor all my loose vermiculite and leftover scoria rock around the oven, then whack the roof on. As long as the loose stuff fully encloses the oven, I might chance some leftover pink batts on top of that, though I think I read somewhere that whatever holds the pink batts together can't handle the heat involved.
The missus reckons it'd look suitably "rustic" if I modelled it on the classic outback dunny, so I'm looking into that.
The flue will consist of a hood directly in front of the arch, similar to the FB artigiano brochure.
So near, yet so far.
Regards,
Mick


Regards,
Mick