Build started in Mountain Top NSW

[Gretsch]

Job done! Looks a million bucks (but that's my opinion only)

Fired it up today, chimney was finished yesterday, so far so good. After an hour or 2 I noticed a couple of bricks have parted slightly on the inner arch, looks like the glue let go and the arch expanded out. I'm not too worried thou.

So it's been sitting idle for at least 2 months while on holidays and building the outer shell so the internal dome must be fairly dry but not completely, because I found some moisture on the wooden door that I put on it for a few days.

The temp reading is between 60 and 200C depending where I aim the thermometer so don't really know which reading is valid for the startup days. Any opinions on this ?

[UtahBeehiver]

Congrats. Take it slow and easy firing. This is the point where builders get impatient and fire too hot too quickly. Take your time, nice work.

[Steady]

Looks good Gretsch

[Gretsch]

Day 1 started the fire at 11am, was a bit nervous, got hot at times so had to monitor the fire regularly. Was listening for the dreaded crack and it didn't happen. Wood was hard to get going and keep going so had to regularly stoke and re-light through the day, I read somewhere on this forum it's the moisture coming out which is the cause.

5pm I did something really stupid. I moved the fire across to the other side, too close to the wall and thought it would burn down and go out, and walked off. Obviously it flared up and I've cracked 3 bricks (see picture below). Sorry UtahBeehiver, I read your post too late. OK, so deep down I really wanted to be part of that exclusive club so I can say I've cracked it. (sic)

Day 2 started the fire 7.30 am, noticed it started easier and wasn't going out as often, kept the fire burning until around 4 pm, at least it was uneventful. It's relatively hard to tame down the fire without it getting too hot, I've had readings off the dome top of 300c and am amazed nothing else has cracked.

Day 3 of firing, continually monitoring and knocking down the fire when it runs away. This morning I noticed some fine lines along the dome top brick edges, could be the dome expanded and has opened up slightly, not sure without sticking my head in for a closer look.

I can feel the bottom of the slab getting warm which is a worry considering I used those light weight kiln insulation bricks on their side (110mm height) but I'm hoping it's the water that's probably sitting in them that's causing the heat to be conducted to the slab, only time will tell.

I didn't put in any vent for the water to escape because I figured (1) Didn't use much water in the insulation layer (2) outer shell is of pressed bricks, they pass water very readily (3) any steam pressure will find it's way out at the heat break, there's a 20mm dia fire rope in the gap. (4) the floor is standard fire bricks so I reckon any water under there should easily leech out between the gaps.

Here's the final specs on the oven dimensions:
Internal dia: 1065mm
Overall external dia: 1770mm
Fire bricks are 110mm and external house bricks were cut down to 85mm which leaves a cavity gap of around 150mm which has 2 layers of blanket and mostly dry filled perlite with some mixed with cement mainly around the very bottom and the top where it was easier to lay, and it supported the house bricks.

Internal arch opening: 495 x 323mm
Internal height: 510mm
And so it worked out I managed to achieve my 63% dome height to opening height

[Gretsch]

Day 4 came and went, pretty much same ol’ burnt for 9 hrs total, started spreading the hot glowing charcoal out towards the edges to distribute the heat out and under the floor to aid in dispelling the water that must be trapped there. Dome top temp peaked around 350, sides starting to ramp up to around 200 and 160 on the first rows of bricks.

Day 5 now and starting to use up more timber. Ceiling peaked 500 before I intervened and spread the burning logs out. Sides are around 350 the bottom row 250.

No sign of cracking so far What I noticed is the brick joints are standing out against the blackened faces, either the creosote is burning off there or I’m looking at brick expansion.

The past week or so has been 30+ which is helping the moisture dissipate, having hit some high readings I’m feeling confident to crank it right up tomorrow.

Thanks to SableSprings comment regarding the chamber depth the stack seems to be doing a good job drawing the smoke out and up, there's lots of creosote on the inner part but hardly anything comes out the front. Very happy chappy.

[SableSprings]

Your build turned out pretty awesome Gretsch! I honestly think that dome builds are like concrete pours when it comes to cracks...every one has some, but not everyone will admit it. Some are bigger than others but the overall construct is still extremely solid and functional. As noted before, with some "antique" builds, the bakers actually use the crack movement/increase to judge the oven's heat storage and readiness to bake. Fancy IR guns are great, but 100 years (or more ago) the toss of flour on the cooking floor and other visual/physical cues were all that the bakers had to go on.

Glad that the curing process is going well...soon you'll be faced with new issues like "How can I make this fabulous pizza better...?" I think you've definitely earned that adult beverage with your first WFO dinner!

[Gretsch]

Cheers Mike, yeah I'm pretty stoked with the end product, everyone says it looks awesome.

Cranked up the heat last night for our first pizza cook, very nervous but was all for nothing. Those bricks just soaked it up.
The pizza was thumbs up, the crust was everything I was expecting. Need to work on our dough shaping skills thou.
I made 2 batches of dough so we could compare the flour, Wallaby brand and 5 Stagioni, an Italian 00 flour. The latter was definitely superior. Softer and lighter in texture.

Now I need a door. I've considered steel with an insulation sandwich but I'm not convinced it would work as well as wood so a wooden door it will be. 2 layers of 30mm ironbark, 60mm total. It's a dense timber with a very good fire rating, it might be a tad heavy thou.

[Steady]

I always love seeing shots of fire in a WFO - your brickwork looks great

[Gretsch]

Thanks Steady, always good to receive a compliment

I'm a bit concerned about the bottom of my slab underneath the hearth. I fired it up yesterday to attempt to bake some ciabata and try out pizza dough that had been frozen.
I put the wooden door in place once I cleared all the coals and the next day to my delight I still measured close to 260 degrees C inside the oven. The dome insulation seems to be working very well.

I fired it up again today and I'm reading 71 degrees C around the middle of the hearth underneath the concrete slab. It seems like the hearth insulation bricks I decided on aren't as good as I thought they would be. Should I be concerned ?

[SableSprings]

Gretsch, I wouldn't be surprised if those insulating bricks got damp during the build and you are seeing heat transferred by the contained moisture rather than by the insulating bricks themselves. Remember that layer between the slab and your cooking floor is sort of a dead end for any water that seeps in. That's one of the reasons David S advocates providing some small holes in the slab to let moisture out more easily. Hang in there, the more times you fire up the oven, the more moisture will work its way out and your insulation will start performing more up to specs. Also a good reason to be diligent keeping moisture off that slab and for sure away from the dome/slab seam perimeter.

Relax! After we've been gone on vacation, it always takes a couple of bakes before our oven starts being consistent in the heat loading (and holding) profile.

[Gretsch]

Wow I would have thought the moisture would have dissipated by now, hopefully youre right. Ive only fired it up to full maybe 3 times so far, the past week weve had rain but Ive kept it covered with a tarp during that time.

Yes I remember David s mentioned drilling some holes, I could still do it from the bottom up but Im now planning to put a roof over it. Reason being Ive seen a couple of (expected) minor cracks around where the chimney stack gets hot compared to the rest and thats going to be impossible to avoid or waterproof, and I want to be able to cook in any weather.

Thanks for the reassurance, Ill just have to burn more wood. And wow...am I going through some! Good thing Ive got lots of sources for hardwoods, a neighbour came over last week with three huge macadamia and pecan trunks. And he lent me his log splitter. Bloody fantastic!

[SableSprings]

Also you'll find that the amount of wood you burn to achieve pizza or bread baking temps should decrease the more you use the oven. Once the oven's insulation is working at top value, wood loads should become pretty consistent. Really glad to hear you've decided to go with a roof over the oven...definitely makes working it year round a lot easier. Make sure to plan the roof large enough to cover some prep area and give you some dry standing room (don't want those adult beverages getting diluted!)

I really understand the value of friends with wood and splitters...and an appreciation of future shares in fabulous pizza (or bread). I have a neighbor that gave me (cut, split, & delivered) a cord of wood that was--shall we say "not chock full of BTUs". It leaves a lot of ash and takes quite a bit to heat load the oven, but it has worked OK and I'd never complain about any free wood cut, split, & delivered! However, I'm just about through that load of free wood and looking forward to getting into my seasoned oak & madrone (both excellent hardwoods available on our west coast) for 2018.

Funny how generous folks will get after being put on the fresh bread delivery route or included in the pizza party list. Keep us in loop for your roof build and how the oven "settles in".

[JRPizza]

My hearth insulation got thoroughly soaked early in my build, but was covered for at least 6 months during the winter and balance of my build. The insulation was still "soggy" and I actually had water running out from around my dome during my curing fires. I also had a very warm slab under my oven till the water was driven out. After about 9 good firings all was good.

[Gretsch]

Mike, the roof is going ahead. Much to the disgust of the wife. Will keep posting progress reports as it happens.

Funny how generous folks will get after being put on the fresh bread delivery route or included in the pizza party list.

Yes isn't it. Reminds me of the lyrics of a Blood Sweat and Tears song.

And when you got money you got lots of friends hangin round your door...

Hahaha

[UtahBeehiver]

You are old if you are quoting lyrics of Blood Sweat and Tears....LOL, my era as well. There have been some very nice roof structures done that still compliment the aesthetics of a pompelli oven. A couple come to mind, Gulf's scissor truss structure with galvanized roofing (I have seen it in person) https://community.fornobravo.com/sea...2%3A%221%22%7D or Leetheldc https://community.fornobravo.com/for...pompeii/page17 . But remember, is mom isn't happy, nobody is happy.