Bo
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Post by Bo on Jan 30, 2014 21:11:16 GMT
Thanks for that Terry, it is reassuring to know stuff doesn't just happen to me!! I'm glad now I did the thermal block/gap thing as I wasn't sure if it would make much difference and I was worried about the arch not being tied into the dome. I don't know when I'll get the chimney on and I need to get more blocks for the enclosure wall but I'll get more pictures on when there is something to show. I'll also keep anyone who is interested updated on how effective the insulation is when I get to that stage! I wasn't planning to start the curing fires for another 4 or 5 days to let the dome dry as much as possible, is this beneficial do you think? Trouble is the weather is due to turn for the worse again and I need to keep the dome covered until I complete the enclosure.... who's bright idea was it to build in the winter !!!
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Post by cannyfradock on Jan 31, 2014 7:44:04 GMT
Bo
I think that as you have large homebrew mortar joints in the dome it would be a good idea to leave it dry and settle for 4 or 5 days before starting your curing fires. I suggested building the outer arch and vent BEFORE starting your curing fires as if not, the outer upper surface of the inner arch will get quite black and, even when using fire-rope etc for a thermal break between inner and outer arch, the gap is usually sealed with fire-cement/homebrew/fire-mastic. If using a heat lamp to start your curing then it won't matter.
Have you thought of buying a gazeebo?.....I've seen them in the cheap nicky nacky shops for about £30. Not sure though that you have the space for one or if you are open to the elements (wind) as it would need to be well secured.
Terry
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Post by rcorbie on Jan 31, 2014 8:43:28 GMT
Looks very well thought trough. It's great you are getting so much done over the winter months. Keep the pictures coming. Enjoying them immensely.
R
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Bo
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Post by Bo on Jan 31, 2014 14:54:15 GMT
I'll leave off the curing fires until the middle of next week I think, that will give the dome about 8 days to dry a bit before being heated I was going to put fire rope into the thermal break gap with fire mastic to create a smooth finish, would I be better off with using fire cement/ homebrew instead? I took out the form for the landing arch today but the weather is atrocious, your dance isn't working Terry!.
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Bo
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Post by Bo on Feb 3, 2014 17:08:33 GMT
There was a wee dry spell today so I managed to get a few blocks laid but then it decided to start raining so I'm hoping the blockwork I've done survives it!! I'm now under pressure from my wife to keep the roof line as low as possible so was half thinking of using lintels to support paving slabs to form a concrete roof, any feedback on this idea would be great. Personally I think the weight would be an issue... Attachments:
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Bo
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Post by Bo on Feb 5, 2014 20:20:45 GMT
I managed to fit a few hours in today so I made up the roof trusses and got most of the sarking on, I have had to leave a couple of bits of sarking off to get access to finish off the insulation like the blanket and vermiculite. The best bit though was now the dome is protected I could light the first curing fire !! Typical, I couldn't find any newspaper so had to settle for cardboard but I kept a wee flame burning for an hour and sat enjoying a beer! I'll put a picture of the roof work on tomorrow but here is one of the first curing fire... Attachments:
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Bo
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Post by Bo on Feb 7, 2014 19:20:54 GMT
A couple of pictures showing the roof trusses on and most of the sarking. I have had to leave a few boards off as I want to cure the dome before putting a thermal blanket on and the only way to get in is through the roof (unless I slim down somewhat!!)
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Bo
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Post by Bo on Feb 7, 2014 19:29:07 GMT
A view of the dome looking down from the roof, I have used 100mm foam insulation board around the block walls and I'm going to fill the space between the insulation and the dome with vermiculite. The dome will be covered in 50mm of thermal blanket first though. It will be interesting to see how the temperatures hold up with this amount of insulation.. I thought I would share the view from the roof of the oven as well!! Attachments:
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Post by cannyfradock on Feb 8, 2014 15:53:15 GMT
Bo
With your concern over the dome housing, I think your low pitched roof fits in very well. A lot of oven builders don't go for the recommended long (1m) chimney extension as it simply doesn't fit in the location. A longer chimney will make it easier for the initial firing to happen but people with a shorter flue (like myself) compensate by making a larger initial firing of bone dry timber (this doesn't have to be your expensive hardwood...initial firing is usually done with less expensive soft wood)....this will put instant initial heat into your dome ...and once hot, the dome will draw well (with less smoking) even with a shorter chimney.
You still have to go through your curing fires process first....try to be patient with these and make small fires as often as possible, building up to fully firing your oven after a 2 or 3 week period.
As much as I admire the view of your oven I really the view FROM your oven....WOW!
Terry
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Bo
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Post by Bo on Feb 8, 2014 16:38:16 GMT
Thanks for that Terry. So far I have had a paper fire burning for an hour one night then the next day a very small fire for 8 hours with wee kindlings and bark. ( I also have a sideline as a firewood processor !!) Today the fire has been on for 8 hours again with wee kindling. Prior to any fire the dome sat for 9 days after I had finished it to dry a bit. I'm planning just to keep wee fires going until next weekend when I was hoping to let rip, do you think that is too early?
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Post by cannyfradock on Feb 8, 2014 17:31:07 GMT
Bo
I always recommend a long curing process to avoid any cracking. If you have the time to continue with slowly increasing the heat until next week-end, then, after reading your last posts I would say....go for it. You don't have to have "silly heat" fired into the oven for it to function, but the true test of putting "enough" heat into the oven is to continually fire the oven so as the black soot which collects in the dome will slowly clear, firstly from the top of the dome, then the soot will disappear from the side of the dome and a clear soot free line will slowly descend down the dome walls. I always use this process to put massed heat into the oven for a pizza party. When the clear soot line is about 9" from the hearth, I spread the coals/embers over the whole of the hearth and leave for about 15/20 minutes before pushing the embers to one side ready for pizza baking. I still wait for a further 20 minutes to allow the hearth to cool before baking my first pizza. If you have fired the oven the day before using, then, it should only take 30 to 40 minutes of firing to see the soot line descend on your pizza making day.
If you have got your under-hearth insulation correct, you should be able to push your embers to one side (as I'm right handed I push my embers to the right hand/rear side which leaves the left and rear totally clear) ....this allows lots of ember free space for trial and error on your first pizzas.
I use a piece of copper tubing, flattened on one end to gently blow any ash to the rear of the oven. I also use a cast iron grill to enclose the embers....or you could use a few clay bricks to do the same thing. (class b engineering bricks with holes in would be perfect for this)....this allows you to toss the occasional log onto the embers to keep a flickering flame dusting over the dome wall.
All the best with your first full firing.
Terry
n.b...I use a minute/second cheap digital timer set at 50 seconds when baking pizza. After the buzzer goes off, I know a crust has formed on the base of the pizza allowing me to turn the pizza easily. Another 30 to 50 seconds of turning and the pizza should be done. If you overdo the toppings simply lift your pizza up towards the top of the dome for about 6 seconds. Trial and error will be your best friend at this stage.
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Bo
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Post by Bo on Feb 8, 2014 19:34:00 GMT
I'm much obliged Terry, a very informative post. I have to say though that when/if my first pizzas go tits up then it'll be all your fault and not mine!! Seriously though I will continue to keep the fires going, trying to slowly increase the temperature ( not as easy as I thought because the bloody thermometer I ordered 2 weeks ago still hasn't been delivered...) There aren't any signs of cracks so far, fingers crossed, so as long as I'm canny. The outside of the dome is quite a lot lighter than it was after I had built it so presumably that is an indication of it drying. I noticed that at the end of today there was no steam coming from the dome though I have to say there was never loads of it just a gentle mist. I think it is a great idea to use engineering bricks to enclose the embers, I'll certainly pinch that one. I've bought a scraper and brush tool so I may not need to use the copper pipe which is just as well as after a few beers I may suck instead of blow!! Thanks again for your support mate. Take care.
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Bo
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Post by Bo on Feb 11, 2014 11:16:12 GMT
A productive weekend. I decided that the worst of the moisture would be out of the dome so I could get on and insulate it. This also meant I could shut the roof off and finally get it permanently weatherproof instead of relying on sheets of plastic! I had already clad the walls of the enclosure with 100mm Celotex foam insulation, and used 50mm of ceramic blanket around the dome. I didn't bother with wire to hold it in place as it moulded to the dome well after I cut darts in it with a Stanley knife. I put it round the dome then another layer in the opposite direction ie at 90 degrees to the first. I then filled the space between the blanket with vermiculite, 9 bags of it !! I think it is worth it as I had a curing fire on until 17:00hrs yesterday then I shut the door and the temperature had only dropped 20/30 degrees this morning when I opened the door at 09:00.
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Bo
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Post by Bo on Feb 11, 2014 11:22:53 GMT
So after finishing the insulation I got the sarking finished on the roof and slated it. I'm not a builder and am known for being a tad impatient but I'm quite pleased with the results, I was always aiming for a rustic looking creation, hence the improvised chimney pot, and intend to apply a smoothish render to the blockwork once the weather has improved. In the meantime I am continuing with the curing fires and so far have accrued about 50 hours of gentle fires. I'm not intending to vastly increase the size of these for at least another week probably longer.
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Bo
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Post by Bo on Feb 11, 2014 11:24:27 GMT
A view of the other side.
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