Pizza History in the Hammer Continues

[Chris inPA]

Baza I did a 6" chimney with a corresponding throat. If I could change 1 thing about my build, that would be it. I should have made my throat more generous.

[Chris inPA]

mongota I loved your ideas of separating the inner and outer arch with a section of rope. I copied your idea using tape, so far it looks like it worked well.

[Chris inPA]

Between the arches immediately before insulation.

[Chris inPA]

Insulting tape

[Baza]

Chris inPA - thank you so much for sharing your build pics here! This is very interesting and I certainly don't blame you for riffing of Mongo's idea! It's good stuff!
I feel like I'm headed in the direction of both you and he ... though I am intrigued with your comment above that you would have preferred a wider throat instead of building one the same size as your chimney (as Mongo did) ... why is that?
Barry

[mongota]

That's one of the reasons I flared the opening of my chimney throat, to increase the initial opening size help coax a more laminar flow of exhaust gas up the throat and into the chimney flue.

The underside of my square throat is flared out for a larger opening, it's roughly 10" square, of 100 sq inches.
The actual dimensions of the throat at the top (square sides, without the flare) is about 8" square, or 64 sq inches.
My chimney pipe is an 8" ID round, or about 50 sq inches.

That stepped approach from larger to smaller (100>64>50) seems to work well on my oven.

I do get a bit of smoke coming out of the front arch when initially starting my fires on the landing floor, right under the throat and just inches from the front arch. Once the fire is burning, most everything goes up the chimney. My chimney is a 4' tall length of double-walled pipe. Once the fire is burning well and I move it back on to the dome floor, I get zero smoke out of the front.

[Baza]

AH! I see!!!
Right - so the beautiful sculpting you did on the throat brick actually widened the throat in the vent to make a smoother transition of smoke TO the chimney.
Makes sense.

I read somewhere that lighting a fire under the chimney (even burning paper/pine cones) even IN the chimney briefly heats it up so the cold air in it doesn't wrestle and push out the warm air trying to come up it!?
Sounds like it makes sense.

Last question I have before the outward flare of the opening.
I noticed, Mongo, that you used full and half bricks the length of your vent ... as such 13.5" ... you've stated this before.
You also noted that you didn't flare the opening but have a wider reveal.

My question lies in the potential loss of vent length if I flare it ... the angle of the flare from 22" at the door to 25" at the mouth will have to be compensated for in the heat break cuts at the mouth of the dome.
As such - this slight angle has the potential to pull the length of the vent in more than a non-flared opening.
in fact - it makes the lip-design you shared harder to do.

in my head it suggest the 1/2 brick cuts around the throat will be cut again to 2.5" at the dome opening arch and about 2" at the vent opening arch ...
The 2.5" cut at the mouth of the dome would be made smaller again by the need to flare at the sides - compromising the lip. no?

Too much thinking perhaps - any thoughts?
Barry

[Chris inPA]

This is my throat from below looking up. I wish I would have done an 8 inch chimney stack and not a 6". Opening up the throat like this does give me more square inches than the 6" id pipe. However, it wasn't enough. I get a lot of smoke out the front. Enough that my bricks are black.

[Baza]

Chris inPA - thank you for sharing your picture and experience! This is very helpful to consider - and it reinforces, not only Mongo's 8x8 approach (minimum) but this reflection is helpful to us all.
I'm sure that amazing oven you built is churning out good food - but the lived experience of your build decisions is most welcome!

I will be having a go at it this weekend - the flared entry may be a game time decision ... but still leaning this way
WONDERING - does flaring a landing/vent area invite more cool air? Should it be more of a tunnel to trap warm air?

Also - hoping my research on Duravent flanges holds in that the plate is 12" square?

Thanks again for sharing your learning and experiences friends!
Barry

[Baza]

Hello Forno Friends!

Well, sad to say I'm going in to HIBERNATION! (sigh)
With all the support of Mongo to envision and understand the vent - I just don't have the time. Thanks Mongo! This will be put to use in Spring!

Weather and time getting away from me, ran out of brick (but happily another builder reached out from this forum who is building nearby and was making a trip to get some more supplies for his build and offered to pick up the brick for me! Awesome people on this Forum!). SO, I'll stack and store the extra brick, tarp and tie down the dome, pull down the tent low and hope all is dry and ready to finish in the Spring - for a summer of cooking and enjoyment!

So, no builds for me this weekend, but definitely went to find fuel for the fire!
Neighbour was cutting down some Ash trees at his church and offered the wood to me for my labour!!! HECK YEAH!

So, Valerio and I spent the morning stocking up on some fantastic and dry Ash hardwood - a good day in spite of no build!
At 87 - he's a machine!

All the best friends ... looking forward to following your builds!!
Barry

[Ope-dog]

Hey Baza, .. I am in the same boat up here in the NW... time seems to be a bigger culprit than $$ on this build. Go figure. lol. Firewood is definitely on my "every-weekend-list," however I'm hoping that the HF canopy I picked up this past weekend will provide enough cover to allow me to work through the winter months on the build. I got the counter top poured this past weekend so hopefully next weekend I can get some moisture barrier down and start getting the base lined up.

Question for you.. what did you use to cut your CalSi board with? Maybe you mentioned it and I missed it? (You supplied great pics in post #44.. and mentioned cutting the board but didn't see what you used..?)

Excited to get going! Bricks and fireclay to be procured this week, although it will most likely be a few weeks before I actually get to cutting and setting..

[CapePizza]

Good haul on the fire wood! Sorry to hear about the "hibernating" issue.... was looking forward to seeing your progress.... but will see it when we all emerge out from winter. TakeCare......

[Baza]

Hey John ... thanks for the support and kind words - like saying farewell to my kid going off to school ... "see you in the Spring my love!"

Ope-dog - wow! AWESOME to read that you are moving forward. I just know the weekends and weather will be too much here. It's ok - something to look forward to!
As for YOU - really exciting to read that you are getting your brick and fireclay (I guess you are doing the home-brew from here - I hear it is excellent!). That first cut into brick is a special moment - and all the ones in-between towards that plug at the end ... excited to know your canopy and enthusiasm will not allow your spirits to be dampened by NW weather!! Good on you and looking forward to following your build!

As for your question: I cut the Cal-Si board with a simple jigsaw! Went through it like butter!
But BE SURE TO WEAR A MASK (not that we need such encouragement these days) ... it has some nasty stuff in it and you don't want to break this as it produces particles in the cut!

Good luck mate!
Barry

[Neil.B]

Barry, you can't leave it now.
I feel like me, you and John all started our builds together and all build the same size...build a temporary shelter and continue on our journey.

[Baza]

Barry, you can't leave it now.
I feel like me, you and John all started our builds together and all build the same size...build a temporary shelter and continue on our journey.

ARG ... I know ... but the weather is colder and unpredictable (look at me tell you that living in UK!).
With all that is left to do - hitting it fresh with time to finish the vent landing, chimney (not in yet), blanket, enclosure, curing ... I'll just wait till the Spring and have a Summer of Pizza in 2021!!
Appreciate the encouragement to keep it going, though!

Will certainly be jealously watching the wonderous next steps of the builds you all have!!