42" In South GA

[MarkJerling]

Yeah. I think there are two kinds of ovens: Those with minor cracks and those with minor cracks where their owners can't see the cracks. LOL

[edonovan]

SableSprings MarkJerling Thank you again for the words of encouragement! I was reading through JRPizza and his words about what they said about a plane being a collection of parts in close proximity of each other at Boeing cracked me up.
I got another two cracks…that I can see…and one is horizontal…not sure if this is any worse than vertical…but I have made my mind up that a lot of this is just out of my hands…
So I have had 10 days fires building temps and moving it around the dome and against walls…I have cleared small sections…and still getting a little bit of condensation on my drop cloth, which I still feel has a little bit to do with how hot/humid it is here and the condensation usually comes around the evening time and hour 4 of my fire, but could be wrong on my theory…is there a certain point where I just “go for it” and build a bigger fire? Is it uncommon to have 10+ days of drying fires? Last 2 questions, what is an average temp on the ceramic blanket if I have 550-650 fire on that wall? And I have read about “overcharging” or building too big of a fire, but the videos I have watched about getting to temp sure stuff it full of wood…what does overcharging it look like?

[SableSprings]

All oven curing times vary, so no - your drying out over 10 days is not too far out. Remember that those recommended times are for long days of drying (not just one fire per day). Do be aware that the plastic cover is just to test for off gassing...not to leave it on 24/7. If you soaked every brick before mortaring it in place, obviously you'll need a longer period of curing (really drying ) fires. Every time you start a fire in a WFO, the inner dome will turn entirely black. As the oven heats up to a point where the carbon burns off (dome top, moving down as the sidewalls heat to temp), it will clear completely. If your outer oven blanket is hot to the touch during a firing, you're still drying off moisture. Stay the course, some builders have had a cured oven get soaked during the winter & had to go through more than a couple of long, low fires to drive the moisture out.

Since in your picture the clearing is complete from the floor up by the fire, I'd say you're darn close to a complete dry out (& yes, what you're seeing may just be condensate from the air). I think it may be time to build a small fire in the middle & keep it going while consistently adding enough wood to keep it burning strongly. I suspect you'll get that top spot clearing & have it move down the dome sides within 1-2 hours.

[edonovan]

You know my wife said something about not leaving the plastic on 24/7...but I won't say anything about her "possibly" being right if you don't . Well... SableSprings when you are right you are right!! Did another couple decent fires and really let air movement get around the blanket more with my tarps down and slowly started seeing lower temps as I shot the blanket, which for me tells me that a lot more moisture got drove out in the higher temps and it was actually starting to dry out. So with the gentle push of my wife to "throw a couple more logs on there" WE COOKED OUR FIRST 5 PIZZAS!! and cleared the dome!! I must say...quite a proud moment...as hesitant as I was it was great to see that dome clear and have my floor at around 650-ish, got the dome to 800-850 and it was "cooking" just outside the opening...we even baked/slightly burned some brownies later that evening. This is going to be so much fun!! and I am going to go through SOOO much wood! As you can see I started on my perlite layer...I think I made it slightly wet...and wanted to double check with you guys, I read about 3 liters of water per 10:1 (perlite to portland)...is that 10:1 10 liters of perlite to 1 liter of portland? And on that note...now that I have the base layer done...has anyone used a cement mixer to mix this up? I know I read somewhere to not use a drill paddle, but I have a mixer and that would greatly help the mixing by hand aspect.
I am slowly accepting my 3 cracks, the more I read the more I understand this is just ovens, with reaching higher temps I do believe they opened a hair more, but again...working on my acceptance ...my latest concern is my underside of my hearth...or storage area...shot that once and got about 105...which I thought was high...however reading more and learning more about ALL the moisture these ovens hold as we are putting them together...I figure my insulation (which is hydrophobic) /floor brick/ and even my hearth is just driving any moisture out. Again, not much I could do about that one...either. I think another big tip I read was the fact that these ovens continue to "season" and even though we reaching cooking temp and cleared the dome 1 time...it still has time to become more efficient and perform even better. I think it was you SableSprings that wrote somewhere that another 10 or more pizza cooking temp fires until they really are seasoned. More pictures will follow as I move up with my perlite layer and move on to stucco...now to start thinking about a door...thank you again everyone!!

[david s]

Regarding the 10:1 vermicrete mix, the water content will vary depending on the grade of vermiculite or perlite you use. The finer the grade, the more water is required. 3 litres of water is a rough guide. I currently use4.2 litres of water for every 10 litres of vermiculite/perlite used. I’ve found from experience that a 50/50 combination of each creates a more workable mix than either of them alone. I currently use medium grade perlite and fine grade vermiculite. In addition, to help make the lean mix more workable, I throw in a handful of powdered clay for every litre of cement added.
Maybe an easier method for water addition is to add water to the dry materials and mix it in slowly. When it pools slightly in the bottom of your barrow, you’ve added a wee bit too much. If too much water is added it washes the cement off the grains. Do not use a mixer, as apart from not being able to check the water content and the mix consistency accurately, it sticks to the sides of the mixer and it’s blades. Additionally the mixer blades tend to abrade and degrade the grains.It should be folded in gently using a barrow and spade.

[edonovan]

david s Thank you, I was able to find what I would consider the finer commercial grade perlite in a large bag at my local hardware store, and threw in some of my clay, with it…I do feel like that first band was a bit wet based on how my hearth looked right around where I placed it. But I definitely found it decently workable.
and thank you for the tips and reasons to not use a mixer, I will stick with the hand mixing

[UtahBeehiver]

Make yourself a curved trowel to place the pcrete, it helps with forming and pressing the material.

[edonovan]

UtahBeehiver Thank you…I was wondering if they sold something like that or not…what is the material you made the curved part out of? A plastic?

[david s]

I do the whole oven in one go, then tap the surface with the flat of the trowel while eyeballing the profile. This is easy enough as my ovens are small. But if your oven is big there’s no problem in doing it in a few goes, working from the bottom and making a flat ledge on top of the row to take the next lot.Allowing this to harden 24 hrs gives you a firmer base to build upon and reduces risk of collapse. Onc you have reached a height where the layer begins to lean in the process becomes far easier. It is important to keep the brew lean if you want it to insulate.

[UtahBeehiver]

The curved part is just an old piece of scrap semi flexible plastic from a sign. I think Gulf made his from a piece of aluminum.

[Gulf]

On this last one. I did not use a curved trowel. The hearth was poured to the pre-determined size. I just used the swing arm to shave it back to shape. The reclaims were put right back into the next mix.

[edonovan]

UtahBeehiver, Gulf and david s Thank you for the tips and guidance…I have some aluminum I can probably use and see how it goes…I had a layer of flashing up 6” from the bottom of my oven so I’ll just be starting where it is just insulation and chicken wire…it is my understanding that I just want to firmly set this against the blanket…not compress or push in too much, correct?

[Gulf]

I use a marginal trowel to apply the v/pecrete. Compress downward and outward against the curved trowel.

[edonovan]

Gulf so very little pressure towards the blanket…gotcha.
Different question…having a heck of a time finding a breather vent that has been discussed in other builds, especially a plastic one…I’d love to stay away from metal but it is what my local place has after stopping at several other auto stores…my only concern is that it is 3/8…is this too small? My ideal is to see if I can make it work by threading it into some pvc embedded in pcrete and if the breather ever gets rusty…I can just swap it out.

[MarkJerling]

The nicest breather vent I've been able to find locally is this: (It's USA made, so make google your friend.)

Morrison 155 tank breather vent 3/4 inch NPT(F) cast aluminium with 2 x stainless steel screens