Hybrid brick/cast pizza oven and smoker. m

[jes2xu]

Sorry about the very slow response! and as usual for the great info.

The price was actually some what reasonable and I can pick it up! Which saves on shipping obviously. But yes I ran the math and it is a little over budget . . . but not by as much as I thought it would be. I don't have the numbers on hand but I will track them down and post if anyone is interested.

I have started infamy and have all the posts set and cut. Hopefully I will get the rest of the support built over the next day or two and can get onto the fun stuff.

I have also planned a arduino project for this oven which should be fun. Im actually kinda excited about that from a purely geeky point of view. I will share when I have something to show for it.

[jes2xu]

Some progress and a few questions . . . .

I managed to get a bit of work done over the xmas break. The slap is pretty much ready to have the supports underneath taken out. I did heed advice and go a little thicker as well.

I have pretty much got the formwork in place ready to pour the insulating layer as well ( P or V depending on prices when I hit the store).


So questions:

Has anyone used glass bottles set in Pcrete?? I have a bunch laying around (im a brewer). Trapping that much air in there will be great insulation. Im just worried about strength and shattering bottles! Any ideas.

Preferences on a flat landing at oven heigh? Or have it step down to bench heigh in front of the oven opening? I feel like this is something you are only going to know after spending a fair few hrs making pizza! I can see merrit to both sides.

Thanks

[jes2xu]

So I have the insulation laid now. That stuff is WIERD! To be honest I find it kind of hard to believe that its going to hold together. But I shall hold judgment on my workmanship until it is properly dry. I did do a ring of rather rich concrete around the outside in a attempt to strengthen it a little. But I do worry a little about expansion etc now. . . . ??

It wasn't until AFTER I had finished this that I saw that the stubbie beer bottles can have a much lower melting point . . . . . Lets hope that doesn't turn into a problem!

So next step leveling and cutting the hearth bricks. I think I am going to lay the soldier's around the hearth rather than on them. Especially if I have trouble with those bottles!

I still can not find clay at anything even close to a reasonable price! What is going to happen if I just omit it from the 50/50 sand/clay leveling mix. and more importantly from the home brew mortar and home brew cartable?? From what I understand the oven is not going to be even close to firing the clay, so is it not just a agregate?

[jes2xu]

I finally got around to laying insulation layer last night (perlite + cement). I got up rather late for work this morning and figured it would be fine. So left it uncovered.

Turns out it is raining cats and dogs at home and I cant do a thing about it.

So now im wondering if:

1) This is going to dilute the cement down to a point where I may have problems. Im hoping that it was set to a point where that wont be a problem. But im not sure. Im guessing if I can see the white of the perlite when I get home it will be a problem. If not im ok ??

2) If im going to have to wait 6 months for this to dry out haha! Next step was to put down some sand and level the hearth. Im guessing its going to take longer to dry now??

3) If there is anything else im not thinking of?

Thanks guys!

Build thread over here if you want pics of the insulation/more details/just want to see it.

http://www.fornobravo.com/community/forum/pizza-oven-design-and-installation/other-oven-types/383235-hybrid-brick-cast-pizza-oven-and-smoker-m/page2

[Gulf]

Yes, it will probably wash the portland away. However, you can reuse the perlite. If that is what you decide to do, I would forget the bottles next time around. You can pour it in layers and let each layer dry a month. Or you can pour it all at one time.There is no rule that you have to wait 6 months on the perlcrete to dry. But, It just may take you more firings to dry the floor insulation out later on. Also, in my thinking, it would have been better to have included this question in your original thread. I can merge the two threads if you like.

[jes2xu]

Thanks for the reply.

Ok cool, yeah if you think it will be better over there. Wasn't sure to keep it all in one place or start a specific thread.

Will wait to continue the questions over there then

[jes2xu]

Thanks Gulf

So what should I look for to decide if the portland has been washed away too much? Or do you think its pretty certain that I will need to redo it?

[Gulf]

That depends on how much and how hard of rain you had. I've dealt with washed out concrete, but I haven't really dealt with this particular problem myself. I'm guessing that the very top will be mostly washed out. In a couple of days you can see what is very easily removed with a stiff paint brush. I'm also guessing that there will be no gray (portland) color left in the washed out layers. If you decide to remove it all, it will be easy to crumble back up once it has dried. Use that for the bottom and use fresh perlite for the top layer closest to the oven floor.

[jes2xu]

Thanks for the advice.

Actually it looks like I'm in luck. I see almost no de-coloring . And for the most part its fairly firm.

Will wait a few days to be sure but I'm quitly hopefully

[UtahBeehiver]

The perlcrete mixture contains a ton of water naturally and with the rain even more. If possible let it dry out as much as possible before laying the floor bricks. The more water you can get out before laying the floor bricks the better. Once the bricks are down, it takes a lot longer for the water in the perlcrete to migrate out. Interesting on the beer bottles, I have seen other website promote this and maybe a few builders on this site as well. I will be interested in the performance. Are you adding any CaSi board too or just the pCrete/bottles? Have you checked with and brickies supply for fireclay? A lot of Aussies have been successful in finding the mortar clay there.

[jes2xu]

The perlcrete mixture contains a ton of water naturally and with the rain even more. If possible let it dry out as much as possible before laying the floor bricks.

Yeah thats exactly what I was refering to when I was asking if I would have to wait a long time. I guess I didnt mean 6 months as a exact date, just was I going to have to wait a long ass time haha.

The plan at this time is to let it stay damp for a week to let it set properly. Then let the wind and sun do its thing on it for a while. Part of me is thinking it may be best to only leave it to dry out for a week or so. I have a 1 year old and a wife that is at the business end of her thesis. So work is slow! Even if I do get the hearth down in 3 weeks from now I doubt very much I will be starting curing fires in less than 4 months.

I am also rather interested to see what happens with the beer bottles. This whole build was all about pushing the performance of a shoe string budget as far as possible. After realising that $65 was the best I was going to get for 100L of perlite I decided to go with the bottles. They allowed me to only use around 80L of perlite. Without them I would have needed another bag for sure. I plan on substatuting as much perlite for scavanged pummice on the dome insulation. Although im not too sure if the salt content will be a problem???

I would love to put CaSi down, but the budget will not allow that I had long ago given in to the fact that this oven will not hold its heat for long periods of time. I am ok with that. The main goals are to make a useable pizza oven (as apposed to bread etc oven) that doubles as a pit smoker. If it works well for those two things then anything else is a bonus!

[jes2xu]

I feel a little guilty for accepting all your help and then going AWOL for so long!! The short days and large amounts have rain had me putting this off for a decent amount of time, but I think its time to get things done!

Progress report:

The perlite layer held up well, I guess it didn't get as much rain as I though.
The hearth is down ( the heater "fire bricks" )
All formwork has been stripped off the base now (and looking much better!
The soldier course is laid out and ready to go

I will get photos up tomorrow (once again raining!)

So the next job is to build a sand castle form and cast on top. I have a few questions that are making me nervous. I plan on using sand:limeortland:fire clay at 3;1;1;1 + SS needles and most likely some sort of fibre to allow water to escape.

1)
What sort of sand can I get away with in the homebrew castable? The photo is "river sand" sold at a local store. The parts that are more like small pebbles make me nervouse? But pure silica is rather expensive. Sand pit sand or mortar sand is cheaper ?

2)
should I mortar the soldier corse together (but not to the hearth) first? Or just basically encase it in the cast dome all in one go?

3)
The volume of the dome is roughly 0.11 m3, but I have no idea how to work out the amount of materials I will need to make that from homebrew mortar. any ideas?

[jes2xu]

I have the temp shelter up properly now.

I think I may mortar the first course to each other at least, before casting the dome. My thinking sugests it will give a more stable base, but I am just guessing there.

I tried breaking up my off cut bricks to use in the castable. You are very right David, that takes a lot of time. I was at it for about a hour and guess I have a little under 2L. So there is no way I will be breaking up enough to use as a good portion of the mix, but I figger I may as well break up all the off cuts into 4-5mm or less and mix that in.

I also have processed a bit of clay. Once again, you are right! I ended up "washing" it as it was very sandy. I processed enough to make some morter with, but have found ball clay FX locally ($50 - 25kg) so I will be using that for the castable.

I will be making a mold for the entrance arch / vent this afternoon. So as soon as my extract fibers turn up I am good to go!

Getting pretty excited!

[jes2xu]

So I finally have a dome!

Gotta say it feels pretty amazing to get this done finally!

In the end we cast a 65mm dome. With a mix of 2.5 Washed river sand : .5 pure silica : 1 Clay : 1 Portland : Lime + a little human hair.

The only real surprise was the large amount of water that seeped out of the insulation base. Im guessing the weight of the sand castle helped force it out?!

Luckily I had my dad to help out as this definitely took a little longer than I thought it would.

[jes2xu]

Long weekends = progress!

We are getting somewhere now. And not running into too many unforeseen problems.

I designed the door forms to be peeled away a layer at a time from the outside. Pulling them out went pretty smoothly, I did have to cut one piece out. The rest came right out after undoing the screws.

I have a few more air bubbles than I had hoped for around the door. I will fill them in later on. Im hoping the dome is better than this though. I did baby the door a bit while casting as the formwork was not totally rock solid (the sand dome was much better).

We are going away for almost 3 weeks at the end of this week. Insulation has been rushed to try and get it done before we go. The plan was to have those 3 weeks as curing and drying so curing fires could be lit when we get back. I probably would have gotten close yesterday, but I ran out of pumice. The weather looks like it may stop this from happening now.

I couldn't decide if I needed both flues, or if one gave enough volume. In the end I went with both (they were "free" anyway), and the only downside in my mind was aesthetic.

[jes2xu]

I cooked my first Pizza in the oven last night. Video linked

It wasn't really at pizza temp, so I added a little suggar and oil to the dough. Came out decent, not great.