Structural Slab for new WFO

[mikku]

Re: Structural Slab for new WFO

Baked chicken-moist, but by the time I got around to eating it--heated twice, it was OK. I think all the hype is in the anticipation--like a kid waiting for Christmas. Had regular pizza twice, different temperatures--door was both times closed. temperature read 375F with door off; when opening door to check pizza was 450F. Did not care how long it cooked as long as it cooked. Made mistakes on Banana Bread--baked at way too high temperature--black all around but inside still moist (edible after minor surgery). Same problem with Rye bread today, read open oven temperature looked fine but after 20 minutes- opened the door to find temperature much higher and rye bread really dark! Getting good at cutting off char from things.

My oven cooking abilities are like a lot of so-called craftsmen I've seen--expert at making garbage out of perfectly good ingredients. I hope it improves with time or my tastes adjust to bad cooking technique..... just for the sake of using the WFO!

Should start a new thread--all the things that can go wrong with cooking in a WFO..."What came out less than acceptable and marginally edible!"

The oven shows no signs of internal damage from my poor firing technique. Insulation and render could use some bandaid repairs. Must still be moisture surrounding this oven! The fire burned for around 4 hours today...that is from fire-up to just a pile of ashes inside. At times, I had some nice oak pieces burning and the dome max'd the IR thermometer at 550C...Everything white right to the floor, only sign of soot is 1/3 of the transition upper parts where the fumes exit the oven and travel up the chimney. The entrance was built as a separate part that also formed the base for the chimney---there is a huge temperature difference between the dome and this area. There was a 2" x 1/2" shiplap section between these sections..I guess a thermal break...but nothing that would physically separate the sections. but still the break is apparent.

The oven was left unattended from 9:30AM till noon. There was plenty of wood to burn inside but I needed to do some shopping and gathering of things. The max temperature I read was when I returned at noon---oven open IR max. Nothing surrounding that is combustible so just let it cure on its' own!

I anticipate firing it many more times before attempting any additional render coats. Just have to figure time when I have days off.

Anybody ever design a vacuum type cleaner to take hot ash and coals from the oven? Bet it could be done if a person were careful with materials--nice to clean out junk when it is still hot!

[david s]

Re: Structural Slab for new WFO

So how was the chicken? Most new WFO owners tell me that their first chicken was the best, most moist chicken they've ever eaten.

[mrchipster]

Re: Structural Slab for new WFO

Well, I think the oven is nearly cured.
I don't have the patience to give advice to new builders who are not looking for advice but want someone to agree with them! My time is too valuable for that! There are may of you who have helped me--you know who you are...Thank you!
You are truely professionals and your experience is greatly appreciated.

Time to move on--and enjoy this new boy's toy!
Sayonarra from Tochigi!

When you get some nice looking food take some photos. I would really like to see one of your first pizza...

Chip

[mikku]

Re: Structural Slab for new WFO

Well, I think the oven is nearly cured.
I don't have the patience to give advice to new builders who are not looking for advice but want someone to agree with them! My time is too valuable for that! There are may of you who have helped me--you know who you are...Thank you!
You are truely professionals and your experience is greatly appreciated.

Time to move on--and enjoy this new boy's toy!
Sayonarra from Tochigi!

[mikku]

Re: Structural Slab for new WFO

Sunday was another oven curing day.

Started the oven this morning --it took off right away and in no time at all it was getting really hot. Today's plan was to do a chicken and not go too hot.

The structural slab- bottom was cool as normal concrete. The perlite and render were cool as well. Was on the internet until around 10AM so the fire had burned down with only embers--no active fire. If I was going to do chicken, needed a door (made one from 24mm floor sheathing plywood, with a little leg to keep it closed) Added a little wood, this time the dome cleared right down to the oven floor. Waited quite a while--maybe close to an hour, then put the little thermometer into the oven--temperature was 220-250 range at floor level.
Closed the oven door--flames were down to a small amount of hot coals again.

The little chicken took around an hour to cook completely, but I noticed that since the door was in place, the dome pericrete was getting hot again. Must still be water in the insulation or below oven. Actually the render was quite warm almost down to floor level.

This evening, the fire had been out since around noon, but the oven was still 325F. didn't look at the C. scale because I had told my wife she could still make cookies or banana bread at that temp. She was in no mood to start baking on a Sunday evening--so kept the door in place, removed the chimney and covered everything with a tarp. Cannot risk an overnite rain.

Other progress--got the oak all split. Need to stack it up another day. Sore muscles tonite from swinging the firemans' axe all day long!

All in all--a really good day!

[mikku]

Re: Structural Slab for new WFO

When I was growing up, my spring part time job was raising chicken! If I remember, they were called " White Leghorn" or something like that! Over a three to four month period, they were raised- loose, but in open enclosures above the ground. They grew from chick size to around 5 lbs. The Italians in my home town loved these chickens because they had yellow fat under the skin! I don't know how old I was, but one year it was 200--next year 400 chicks. Sold them by their live weight, but plucked and cleaned them for sale. BTW never gave them any names--too many to remember! Also, they are very stupid cannibals--if any of them had a distinctive feature--like a missing head feather or something like that--the others would peck them to death! Poor thing would run around and everyone would peck at the odd feature until the chicken was dead --then they would trample it flat!

Current cage raising is not much better--chickens cannot even move enough to see their butts--eat, crap and when large enough get butchered!

Another life story! pretty soon I'll run out! cheers and enjoy your chickens!

[mikku]

Re: Structural Slab for new WFO

You never fail!
Thanks for the advice, tomorrow is "frozen brazillian chicken" no name, baked in a WFO with no lid!

[david s]

Re: Structural Slab for new WFO

[ Have a cast iron deep fry pan with pyrex type lid--works

What do other people do to get a whole chicken? Grow their own? Maybe another good idea--except they would get names right away and then it would be difficult to eat someone you knew on a first name basis![/QUOTE]

rule number one. Never give an animal you intend to eat, a name.

We always use the open roast technique. Ie without a lid. It crisps up the skin yet the meat is left delightfully moist.

[mikku]

Re: Structural Slab for new WFO

Great news! found two dead frozen chicken from Brazil! I don't speak Portugese so I could not ask them if they were good or not! 1 KG - 500 yen! What a rip, could get breasts for same price but 2KG! Sure love breasts

The oven got a day off! Saturday will be the 4th gentle burn, and I hope the frozen chicken is thawed by 6PM. If you have a special recipe for frozen chicken (always welcome) for first WFO feast! Have a cast iron deep fry pan with pyrex type lid--works for regular ovens! So, if I am gentleman-like--it should be O.K. for the wood recycler!

Oven turns dried burning oak into fluffy gray ash! Back to nature!

Something addicting about a flame--just like watching it and enjoying the warmth!

What do other people do to get a whole chicken? Grow their own? Maybe another good idea--except they would get names right away and then it would be difficult to eat someone you knew on a first name basis!

[mikku]

Re: Structural Slab for new WFO

Hello David s!
That was a joke about trying to see flames out of the chimney. But I have no doubt if you put enough wood in at one time, there would be flames jumping out of the top... right now, I have pipe scaffolding surrounding the oven and galvanized scaffolding planks on the top--I want to be able to put a tarp over everything in case we get rain-- cannot build any kind large fire.

There has been no visible steam anywhere, but when I uncover the WFO in the evenings after having it covered from when I leave for work--5:45 or so, there is moisture on the pericrete/and render. But nothing feels hot anytime on the exterior of the oven--at anytime anymore.

Gotta see if I can find a chicken somewhere to cook. Only whole chickens I have seen recently were the frozen variety from Brazil--they look more like Robins by their size. Only things that fly around here are crows and ravens, little too chewy for my taste if you could catch one--"no guns in Japan" except for the police, military, and underworld groups.

I don't know if cars need to be broken in anymore.. with old type bearings, that may have been the rule...I think the new engines could go 100% right off the line and do fine! But I don't know anything about things like that---my wife tells me I don't know anything about anything! She says that I keep on "jabbering only to hear my own voice"...maybe its true! Get senile from hearing foreign words all the time ---

As far as being a "gentleman", I am practicing singing country songs --my the late "George Jones" while driving to work. The Japanese drivers must think I'm nuts to be mouthing words behind closed windows...Or maybe they think I'm just another "stupid foreigner"! Probably both true! Cheers!

[david s]

Re: Structural Slab for new WFO

The seven fires in seven days routine is designed so that people do not jump to big fires straight away. You should proceed slowly or you are asking for more trouble. If you see visible steam then you are going at it too fast, back off. Flame up the flue is also a no no and asking for trouble.

Think of your oven as anew car. You wouldn't jump in it and drive it up to max speed the first time you drove it. Be a gentleman and treat it gently.

[mikku]

Re: Structural Slab for new WFO

Tonight, repeated yesterdays' routine. Started with some kindling that started almost immediately when you put fire to it. Monster took off burning right away. Added a couple of pieces of oak and let it burn --most of wood was consumed in flames--but right before going to coals, pushed everything to center and rear. Whole flame pattern changed--instead of flames licking forward--now the tips pulled to the rear and washed the dome with their tips.
Even the coals began to glow more brightly. The oven was drafting real nice and only hot vapors were being emitted from the chimney!

Nice to see the oven burn so clean. Even the pericrete and render stayed cool..must be an indication that the moisture is beginning to be drawn out. have to do the same tomorrow. A nice chicken might cook now, but chicken in one piece is a rarity in these parts. You can buy dressed chicken breast (8 nice pieces- 2 KG- for $4.50/pkg) but if you can find a scrawney chicken in one piece--they want $12.00 for this bird! Rather buy a slab of pork loin for the same bucks--Have to figure out how to do one of these in a WFO--in slices deep fried....I know the routine.

[mikku]

Re: Structural Slab for new WFO

Got home early enough from jobsite. New house is near Honda automotive manufacturing- Kiyohara. There are alot of "just in time" suppliers located in the same area--so there is a real rush of traffic in the mornings and repeats around 5-7 every day. If I get to jobsite before 7AM then rush is avoided--if I try to start like normal people at 8AM (takes 2 hours) to travel to site vs 35 minutes. Dah! Start earlier...

Tonite was second burn--for curing (no rhyme or reason) but this time the insulation layer of dome was cool to the touch and so was all the render.. Sunday's burn must have driven a lot of the moisture out.. Castable refractory showed no signs of distress -- maybe a few more burns then "light it up for real"!

No new cracks on pericrete or render--must have been like you said --Davids--water has to get out, and steam builds pressure.. Relief valve are the cracks!

This week-end, have to see how high of a flame I can get roaring out of the chimney--see if stainless melts! Whoopie!

Lots of short; dry, pine scraps from jobsite too! --good to get an initial bed of coals then go for the good stuff--dry oak or ash!

[david s]

Re: Structural Slab for new WFO

Perlcrete directly against the refractory does work, but it needs to be dried out. See my PM

[mikku]

Re: Structural Slab for new WFO

Thank you for your observations. I have a couple of questions maybe you can fill me in on.

1) What is the history of pericrete--i.e. who started recommending using it?
2) Are there any commercial oven manufacturers who use pericrete in their product that is sold?

A couple things about me--you probably know by now, that I am not a patient person, but I think that I can produce quality products--not necessarily WFO's--but in the other things that I do.

I think that this design is flawed--because there is nothing that will absorb the expansion of the refractory when pericrete is in direct contact. Please correct me if I am wrong!

The render coat that I did, was relatively thin--approximately 9-12 mm thick on the dome itself, but it was rock hard. It takes a lot of pressure to make cracks in that!

I really do not care of the pericrete cracked now in initial firing--or the render either.. Yes it can be covered again. But when the oven is "dry", refractory still expands when heated--and the same situation still would exist. Nothing to take up for the expansion.. That is what I am concerned about! I do not want to be rendering over and over until the cows come home.

A few people around here are interested in WFO's like mine, but I told them--I am not interested in selling anything that I do "Until" I get the bugs worked out!
And if you make more than one, you can't be waiting around for pericrete to dry out! So looks like trash that idea altogether.

I know that you have made several ovens, I do not know if you have sold any to other people... I would rather give them away for free than to sell one and get continuous call backs because of avoidable design flaws. Just not worth it. In house building, I try to avoid bad designs OR if it is an architects' project, I alert them to what I see as potential problems. Then, I am half "off the hook" if something does go wrong.

I noticed when firing, that the top of the oven "pericrete" felt very warm to the touch--also areas where cracks appeared were hotter.. Da--direct path to refractory! Most of the other areas including the chimney were rather cool. The IR thermometer did not give readings over 200C anytime during the day... Most of the readings were in the mid to upper 100 range. Hottest area was the top of the transition--where smoke and heat exited before going out the chimney. Never was the fire anything near roaring..usually flamed up and then went back to smoldering embers when the easily combustible fuel was spent.

Cannot see any damage to refractory that was poured in January and able to withstand temps to 1450 deg. C. Really thought that it was a slow burn! Sorry if I sound Irish!

Anyway, yesterday was my only day off for a while--have to jerryrig some decent cover so the oven does not get soaked! Thanks again!