Pizza History in the Hammer Continues

[Baza]

Hey Forno Friends!

The LAST BRICK was laid today!!
Completed the Chimney assembly now that the base transition is in place on the vent arch.
Lots of cuts here - but happy with the result.

1. First set of bricks were cut out the depth of the chimney plate much as Utah and Modified9v did. Ground down to be flush when the plate is put on.
2. Plate put in place - happily the mortaring on the base transition ensured the plate is level. I asked about mortar to hold the plate on to this level (or silicone) - general consensus was not to as the silicone - under heat - would likely fail here and there is no space for mortar underneath (also allows for some expansion)
3. Cut full bricks in half length wise: 2 bricks made 4 thin 1/2 bricks. Cut out the space around the flange with enough room for chimney. Mortared down this last layer over the plate - cleaned out the space around the flange.

Test fit the chimney and all worked out! Very happy!

[Baza]

Forno Friends!

Well - moving on to the insulation of the dome!
The vent assembly is complete and the smile on my face is genuine!!
I'm very happy with it - wow.

Starting the insulation - at 3 layers (3") at this point and ran out (working from one full roll and a bag of scraps from my friend who owns a refractory company.
I have about a 2' x 7' swath to complete the 3 layers all round and he is going to let me steal more scraps! Wooo!

QUESTION: can I be content with 3" of blanket knowing I will be building an enclosure and filling it with vermiculite all around inside? Should it be 4"?
FB plans suggest 1' and 3 (4cu ft) bags of vermiculite or 2 50ft rolls ...?
It seems the accepted thickness of blanket on the forum appears to be 4" ... should I shoot for that with the 4" layer of loose vermiculite that will be on top in the enclosure? Too much?

Not sure what the sweet spot is? Help!
Barry

[Petter]

Great work!

insulation thickness:
https://community.fornobravo.com/for...retic-apporach

pick your choice.

[CapePizza]

Hello Barry.... FWIW, I put 3 layers of 1 inch blanket, wire lathe, and about 3 inches of perlcrete mix over that. If you haven't seen this FornoBravo YouTube video on applying the insulation, it's well worth a watch. I found it very helpful. https://youtu.be/Lq4lpzK-uFQ. Also, FWIW, I'm finding if I cook pizza one night, getting the oven up to 800+ degrees, the next day it's still around 450-500 and the day after that around 250. It's really very cool the way it retains the heat.
Your oven is looking great!
John

[NCMan]

Looking good, great job!!

[Baza]

Thank you Friends!

Very appreciative of your input on the next steps. Unfortunately, this is one of those moments when the engineers on the forum eclipse the plonkers like me!
The best I can understand from reading the data is that a 1:1 ratio is best? So, if the brick is 4.5" thick, the insulation should be too?
Yet others feel the blanket insulation is deemed TOO thick in that ratio by some. It is such good info lost on me! ARG.
Petter I am grateful for your sharing - I'll return to it and try to understand more!
CapePizza I think your experience here is helpful to my build.

Given I will be enclosing the structure and filling the enclosure with vermiculite (as many of you use vermicrete to finish, thermally and aesthetically, your domes) I believe 3" of blanket and 4+" of vermiculite all around should do the thermal job. That is my hope in a world where I don't complete understand the physics/science of thermal materials - but am SO appreciative of the door opening by those that chimed in!

Thank you
Barry

[SableSprings]

You've done a fabulous job Barry & your build will be referred to often. I never thought about a ratio of covering insulation to actual brick thickness. I just have always gone with the standard 2-4" of batting is plenty for heat retention. Once fully cured & with all that insulation, you'll be able to cook/bake for days after a pizza party! Soon you'll finally be enjoying the fruits (well, more likely pizza ) of your labor.

[Petter]

The optimum 1:1 ratio mass:insulation is only valid for a fix wall thickness. Like if you shall do a casting and your stand is already built or you just want to minimize the oven footprint.

More insulation is allways better. But sometimes you are restricted.

Since your bricks are fix, one could say that anything under 4.5" insulation is non-optimized. You gain performance all the way up to about 1:4 in thickness ratio, I.e. Point of disminishing return.

Your plan of doing 3 + 4 is very good.

[GFI]

Hi Barry, by the way, I know you were going to Elvis for Vermiculite...you can also order Perlite from the big orange store. Just over $60 for 4 cu ft delivered to your house. I'm going to do the 50/50 Vermiculite/Perlite mix. The Perlite was delivered today. Bit less than a week delivery.
glenn

[MarkJerling]

Forno Friends!

Well - moving on to the insulation of the dome!
The vent assembly is complete and the smile on my face is genuine!!
I'm very happy with it - wow.

Starting the insulation - at 3 layers (3") at this point and ran out (working from one full roll and a bag of scraps from my friend who owns a refractory company.
I have about a 2' x 7' swath to complete the 3 layers all round and he is going to let me steal more scraps! Wooo!

QUESTION: can I be content with 3" of blanket knowing I will be building an enclosure and filling it with vermiculite all around inside? Should it be 4"?
FB plans suggest 1' and 3 (4cu ft) bags of vermiculite or 2 50ft rolls ...?
It seems the accepted thickness of blanket on the forum appears to be 4" ... should I shoot for that with the 4" layer of loose vermiculite that will be on top in the enclosure? Too much?

Not sure what the sweet spot is? Help!
Barry

Looking great Barry!

[Ope-dog]

Hey Barry, I wanted to check in and see how you were getting on with the vermiculite layer.. more specifically, if you were going to loose fill your enclosure or do a mix and hard coat? I started my v/p layers yesterday. I will fully admit.. my least favorite part of the entire build thus far. Man, that stuff is obnoxiously onery to work with!!! lol

[Baza]

Forno Friends!!!!

IT HAS BEEN SO LONG since updating this build and connecting with all of YOU! Work has been a bear and just haven't had the time to work on it since my last post in May.
SableSprings MarkJerling - thanks for the encouraging words (as always!)

BUT - certainly had some progress recently .. will update!

Petter thank you for the confidence in the solution re: insulation - I went with 3" all around (will share shortly) and will top with loose vermiculite in the enclosure.
GFI I'm very grateful for your sourcing of the perlite! I will be seeing Elvis and crew shortly - so going that way anyway - if I come up short on my calculations - I'll take that route!
Ope-dog thanks for the check in - as mentioned - will be doing loose vermiculite in the enclosure - no hard coat for me as I do not trust my ability to seal it well enough to survive the freeze-thaw cycle here in the Great White North! HA! Kudos to those who can!

It is going to move quicker now ... deadline for first pizza party is my Birthday - July 31 - and it HAS to happen!

[Baza]

INSULATING!

So - got the insulation sorted!
Tapcon'd screws into he hearth floor after wrapping 3" of blanket around the dome (am I alone in that I was kinda sorry to see the bricks go??).
Going to pour 4" loose vermiculite all around/on top to finish the thermal protection once the enclosure is built.
Secured the blanket in place using rebar wire left over! Worked great - holding firm!

QUESTION: I don't have the chimney on - so not starting the curing fires yet (and it is covered by a tent given the amount of rain we seem to get 2-3x weekly that would go up like a torch!) - but wondering if I should WAIT until the enclosure is built and the vermiculite is in place for the curing fires to start? Or start now with just the blanket - and remove the tent to do it (ugh)?

Thanks for any insight!
Barry

[Baza]

ENCLOSURE

Hey Forno Friends - got the base of the enclosure going!!
Using 18 gauge steel (saw the 25 at the box store - whoa! - big difference - was like aluminum foil compared to this stuff!). Was my first time framing let alone using steel to do it.
Couldn't use snips - had to cut with 14" chop saw and 4.5" grinder - both with abrasive wheels. Cut like butter (but did leave burring that I had to snip off).

Used basic framing principles: keep it level and square! and have 16" on centre studs.
Felt somewhat flimsy until I capped the top in place - WOW - bomb shelter! I was very happy with the result! The bubbles in the levels tell me things went well too!

Great learning!
Oh - note - I'm glad I used an impact drill over a simple drill - power/start-stop - all the mechanical plusses to make this piece go well.

[Baza]

TRUSSES!

Got these done today - feel good about how they turned out!

My chimney flashing is about 30 degrees or 7/12 slope - I used this dimension to build a simple form to build each truss (other builders here gave me the idea! True for EVERYTHING!)
Cuts and fastening went well (those little self-tapping screws are bullets!! WOW - right through no worries!).

Front and Rear-facing trusses had cross-beams/rafters(?) recessed into them as they will be facing outward to hold studs for the cantilever and couldn't just slap on the back like the others (come to think of it - the rear one could have ... sigh ... hindsight). But the front needed to be flush as it was SO close to the chimney (in fact, in the previous post - you can see I had to cut out the front cross track to accommodate the chimney - it won't lose that much instructional integrity ... he hoped!).

Lined up the trusses today for square and just have to move one upright stud a bit to make sure it is directly under where the truss will sit (causes it to be a bit off the 16" o.c. - is that a problem? should I put another upright stud beside it? or is this assembly strong enough?)

Finally, going to build the cantilever parts on the front and back trusses BEFORE putting them up in place (just easier I figure, we'll see). Going to put them up tomorrow!