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Post by Calaf on Feb 27, 2012 17:15:25 GMT
Hi Bookem, Tony
Thanks for the reassurance, much appreciated. I had a third firing at the weekend (what glorious weather for February). She opened up the crack in exactly the same place. I think she's telling me, "this is where I will release the stresses."
I lit a fire, further back this time, then thinking I might make a test flatbread I knocked up some dough. The roof of the oven reached 475'C however the floor of the oven directly in front of the fire only averaged 165'C. Hmm.
I suspect the issue here is that I used a makeshift firegrate from an old Outback barbie cast iron grill. This raised the fire off the floor which I now realize may be a bad idea.
I'll wait til I have the ceramic fibre blanket installed before fire #4.
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Post by Calaf on Feb 27, 2012 17:21:56 GMT
WOW! You obviously know your onions. All the diagrams are going to be of great help to me for planning if you don't mind me using them. You could even put them together into a pack and sell them online I have a question about the transition... you have used a halfbrick to join the oven to the where I assume you will build the chimney - other builds use a full brick - how would this affect performance? Could a longer transition help retain the heat? Tom Thanks for the kind words, Tom. Anybody is free to use my plans. Interesting question about the transition and one I hadn't thought about. The reason for the half-brick throat is purely to keep the oven compact and the weight rearward on the cantilevered platform. I would have to leave it to the experts to answer your question about performance.
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Post by tonyb on Feb 28, 2012 20:16:00 GMT
Calaf, I think the temp differences are inherently linked to the design. During firing and pizza making, the roof will always be hotter than the floor, due mainly to convection and to be fair I think you need that for good pizza. The floor and roof do equalise out during retained heat cooking though.
Separately, but linked I didn't do enough to isolate the wfo floor from the ground (my wfo is built into a terrrace) and always struggle to get the floor as hot as I'd hoped.
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Post by veauifru on Mar 5, 2012 11:56:16 GMT
I will be interested to know how you build the door and how you fit it to the oven. Will it be hinged?
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Post by Calaf on Mar 5, 2012 16:28:47 GMT
Hi! No the door will just slot into place isolating the oven from the flue but it's good idea.
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Post by Calaf on Mar 6, 2012 16:14:22 GMT
I have taken a break from work on the oven these last few days as I needed to catch up on some garden chores. Back to work now. My original plan had a block and render enclosure but I recently acquired over 200 hand-made clay bricks for £5. These have to be some of the ugliest bricks I've ever seen, being a mixture of flesh pink and vomit yellow but for £5 I decided to take a punt. I tried soaking them in orange dylon but that seems to have made little improvement. 200 clay bricks..........£5 A man with a dog Orange dylon............£3 Hardware store Portland...................£3 Selco 2 bags Builders Sand...£4 Selco Total.......................£15
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Post by Calaf on Mar 6, 2012 16:22:27 GMT
Contrary to BS 5628-3 (I am such a rebel) I am laying the bricks frog-down to minimise the weight when I get to the chimney stack. I used Rugby portland which seems to have resulted in a darker mortar than Blue Circle. Looks OK I think. The texture on the bricks is like a cute elephant skin and even the colour is starting to grow on me.
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Post by turkey on Mar 6, 2012 21:07:44 GMT
no idea how them 2.5p clay bricks look in the flesh (sic) but they do not look that bad at all from the photos. I am sure a bit of old fashioned weathering and soot from a good firing will give them more character.
I think the darker mortar with the lighter bricks looks good. Wish my pointing, or rather wish i had done some pointing as I layed bricks looked half as good.
Failing to adhear to BS standards, next thing you will say is your project is not ISO 9001 certified?
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Post by victor on Mar 6, 2012 21:56:12 GMT
It is not a good idea to lay that type of brick with the frog down for the reason that the face will not shed rain as it should, it would be condemned if it was on a house build.
But who am I to say not to flirt with unorthodox, I did many times on my build.
Vic
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Post by Calaf on Mar 6, 2012 22:35:36 GMT
Vic, is that because of the curved grain on the face?
Fortunately the two side walls are only 4 courses high and the roof overhang will keep most of the rain off.
Turkey, I mis-typed. It was 250 bricks, so 2p each. ISO 900x is such BS. Just pay the consultants their tithe, wave some management diagrams about and you're done.
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Post by bookemdanno on Mar 7, 2012 13:17:37 GMT
They look like an Ibstock Multi-buff or similar. ISO...not worth the paper it's written on!
Looks like it'll be lovely Calaf, good choice!
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Post by cannyfradock on Mar 7, 2012 19:09:49 GMT
Mark
Personally I don't like the air drying ready-mix fire cement...to me it's a bonding agent used between 2 tight fitting pieces of masonry used in refractory situations. I would always trust in the homebrew mix of 4:1:1:1..sand, powdered fire-clay. lime and cement.
The crack looks to me a classic case of curing fire too hot...while moisture is still within the dome.....I only realised how much moisture needs to be driven out of the dome before putting too much heat into the oven, when I cracked the dome of my first build. It doesn't affect the structure and wouldn't affect performance.
You're at the stage of the build, which I am really interested in. Most Vault ovens transition from vault to vent/entrance use angle iron....I think you said that your transition will be purely masonry....I'll be "watching this space"...for your next stage.
Terry
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Post by cannyfradock on Mar 8, 2012 18:47:06 GMT
Mark
....missed a few earlier posts on your thread. I like those bricks. There's a nice rustic look to them and I'm sure the finished job will look impressive. There are certain bricks which can only be laid one way due to the contours of the face...those bricks aren't that type. As a brickie I've learned that the only problem in laying bricks frog down is that the the void is sometimes not full with mortar and if water ever gets into the void it can freeze and expand in winter and "blow"the mortar.......this would only happen on exposed gables on a house build...
Terry
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Post by Calaf on Mar 12, 2012 11:28:50 GMT
Bookem, I looked them up on Brick Hunter and as you say an Ibstock Buff was the closest thing. Couldn't find the exact colour version however.
Terry, "bonding agent" is the perfect description for the stuff.
Bricks: The gables end will be cement board, to save space. I read the British Standards on frogs and it says it weakens the structure laying frog-down as a smaller area is taking the compression. Not an issue for such a small structure but I've paid special attention to pointing ensuring no water can get in. I have some stabilising solution for added protection.
Transition: The chimney will be bonded to the oven's door-arch with vermicrete. It'll sit on a brickwork arch so no need for iron. The upper 5 voussoirs will simply be divided to create the flue and door reveal. I'm getting more confident cutting bricks now thanks to all the encouragement here. Confident but not competent.
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Post by baronkev on Mar 13, 2012 11:08:18 GMT
Them bricks look fine Calaf. looks good. soon you will be baking the best bread you ever tasted.
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