Bacterium's 2nd build

[oasiscdm]

Re: Bacterium's 2nd build

Hey Damon

Have PM'd you.

[Bacterium]

Re: Bacterium's 2nd build

Thanks Colin.


Ok guys I'm still undecided......Instead of shiralite, could one do vermicrete (say 20mm) above and below the blanket.

My questions being...
Do you need to make it safe between oven dome and blanket, so no CF ends up inside oven.
And
To minimise blanket compression, do you need vermiculite between outer render/stucco and blanket?

......!!

[david s]

Re: Bacterium's 2nd build

The CF could be dangerous to inhale rather than to ingest.
The blanket is relatively dense and does not compress if rendered over, but it will be lumpy where there are folds and joins so rather than using tons of render you can get the shape back to spherical with vermicrete then render over it, but there's nothing stopping you from just adding more and more coats of render until you get the form you're after. If doing it this way each subsequent layer of render should be weaker (ie less cement more lime) than the previous coat.

[Bacterium]

Re: Bacterium's 2nd build

Davids,
Thanks. Yes I will use vermicrete to relevel on top of blanket, rather the using render to get final shape

So would a layer of vermicrete under blanket afford a protection layer under blanket....eg. risk of inhaling CF fibers getting through potential cracks, to inside of oven
Or would people see this as unlikely (CF doesn't break down like that ).

Sorry if this sounds paranoid......on my last build I was only days away from finishing dome that I asked about underfloor insulation...... I Tend to ask more questions this time around.

[david s]

Re: Bacterium's 2nd build

It would have to be a sizeable crack for any fibres to find their way through. Hairline cracks would be ok. A layer of vermicrete is also likely to crack a bit although it would be unlikely for any cracks in that layer to coincide with those in the dome. Although tumours have occurred in rats exposed to CF there are yet none recorded in humans (yet)

[cobblerdave]

Re: Bacterium's 2nd build

Gudday Damon
Pink Batts , fiber wool , rockwool . Cut it bend it, push it around,the fibre in the air are potentially dangerous if inhaled . Once in the structure of house, encased and left alone ... Just do the job they were put there to do ... Insulate.
Same with the ceramic , sealed away , not anywhere to be cut or bend or prodded the same ,it does its job ...insulate.
The red brick roarer was a great oven, you enjoyed building snd cooking in it ...But this one will go one better with its insulation!
Regards dave

[Bacterium]

Re: Bacterium's 2nd build

Thanks Dave.........There are so many new recipes (for me) that I want to try.
Dougs cooking thread will get plenty of use.

Yeah funny as an electrician that's one of the things that drove me to get off the tools........all those itchy fibres of insulation types in roof spaces.
My dome smoothing coat is drying nicely which will give the blanket and even/smooth surface. Weather permitted I could get blanket and vermicrete on.

[cobblerdave]

Re: Bacterium's 2nd build

Gudday Damon
This part of the build the ceramic blanket and wire is the part that so many worry over. Don't. It's an easy part you have done the hardest bit, the top layers of the dome!
The CF blanket is stiff but will easily be cut and pushed into position then you will find to your suprise it will stay were it put. It will not flop down it won't try to spring away from the dome. It will just look a little lumpy at the end.
A bit of tie wire at the joints is all it needs really,it will stand up by itself!
The chook wires the same. Remember its not to be a work of art it's just there to hang your pearlite or render off!
Run a tube of chook wire around then CF covered dome with the connection at the side, cut out the entrance way and connect it up.
You end up with a big tube standing upright on the stand yes by itself no tie downs required even around the entrance cutout.
Cut down from the top with tin snips to meet the CF and fold the strips down on the top of the dome. No fancy cuts just overlap it and wire it together.
Now you have a few baggy bits... No worries. Grab a bit if one of the wires with you flat nose pliers and twist, do the same to a few more and the baggy bit will disappear. But don't try for tight it there to hang you render off once that's on there it will never be seem again.
So in a nutshell don't over think it it is a easy task . Both the CF and the wire will not be perfect. The pearlite and the render layers will take care of that!
Hope this helps
Regards dave

[Bacterium]

Re: Bacterium's 2nd build

Dave.......so right you are.
Less thinking.... More working

All suited up, work area well and truly saturated from large rains Friday. Temporary shelter in place I got cracking on Saturday.....
Blanket x 3 generous layers on.......
Vermicrete layer applied on top of that....... Basically I used a 100lt bag to bring it back to the igloo shaped.
Even managed a small curing fire Sunday night. I will redo a series of curing fires over the week to push out any moisture from the dome capping layer (under blanket). Can't see it hurting the outer vermicrete layer (over blanket), which . As long as I manage the heat and not too much steam occurs.

Wooooohhoooo first proper pizza cookup sometime this weekend....

[Wayne73]

Re: Bacterium's 2nd build

Good on you Damon, I'm thinking ill be right for cooking this weekend too

[oasiscdm]

Re: Bacterium's 2nd build

Hey Damon

photo's please...............

[Bacterium]

Re: Bacterium's 2nd build

Hey Damon

photo's please...............

Yeah I got so engrossed forgot to get me camera out.

[david s]

Re: Bacterium's 2nd build

Dave.......so right you are.
Less thinking.... More working

All suited up, work area well and truly saturated from large rains Friday. Temporary shelter in place I got cracking on Saturday.....
Blanket x 3 generous layers on.......
Vermicrete layer applied on top of that....... Basically I used a 100lt bag to bring it back to the igloo shaped.
Even managed a small curing fire Sunday night. I will redo a series of curing fires over the week to push out any moisture from the dome capping layer (under blanket). Can't see it hurting the outer vermicrete layer (over blanket), which . As long as I manage the heat and not too much steam occurs.

Wooooohhoooo first proper pizza cookup sometime this weekend....

If you see steam then you are going too hard.
100 L vermicrete means you've added around 30 litres of water. That's a lot to get rid of. Try to let the sun and wind do some of the work for you. Unfortunately this means waiting time. When you think it's dry throw a sheet of plastic over it to see if any moisture condenses under it. Wait until it's dry before doing the outer shell.
Haste at your own peril.

[Bacterium]

Re: Bacterium's 2nd build

Well that was a great weekend....pizza and bread!!.....just

During last week I slow cured and there has been a noticeable amount of moisture being removed. Every time I took tarp off between rain there was plenty of condensation to shake off. I've decided to wait to its completely dry then final render coat to go on (you will notice the vermiculite skim layer to bring the shape back).

So by Saturday night I carefully took it to pizza temp (only just removed black off inner dome) and did 8 normal pizza (2 were garlic pizzas) and a gluten free (which my lad who needs it...quickly devoured). Next morning oven was only 110Deg c, so I re-fired it a little to bake some bread. Probably not enough if you look at my breads
.....If you throw one of them you might find it comes back (boomerang).

Dome outer seems good, no actual steam or hot spots just moisture working its way out.

I quickly made a temporary door out of Hebel but it leaks too much heat out the top edge. Still though was pretty impressed how well it works as a material. I've also got to finish the front landing so the front edge of the oven floor is still pretty exposed.

overall it's great to get that WFO pizza feeling again.

as usual ...thanks for all those who chip in and provide build comments.

[Bacterium]

Re: Bacterium's 2nd build

here's a couple shots of my temporary door that I hacked out of a bit of undersized scrap hebel.


the rope is holding my tarp down for a bit of wind and rain forecast for next few days.