So it begins ... (in NZ)

[shuboyje]

Looks great.  Can't wait to see it in brick and mortar.

[kiwipete]

Would like some feedback on this:

I'm looking to use a steel door / opening similar to "fagilia" in the thread "Finally a Swedish neapolitan WFO underway" as per the attached picture.

I'm using a typical concrete hearth with 6" of perlcrete on top for insulation, and would like to bolt the oven door directly to the concrete slab, because it will also have the stainless steel straps that act as a buttress attached to the back of it and so needs to be reasonably solidly mounted to something.

One thing that concerns me a bit about this, is that the door might lose/soak a lot of heat into the concrete slab. Am I just over thinking this one?

Comments appreciated please.

Peter

[TXCraig1]

I don't think that is going to be a problem. The thermal conductivity of concrete is pretty low - depending on the density, probably 0.5 - 1.0 W/(m.K). It's not going to move much heat out of the steel.

[Tscarborough]

Personally, I think the cast iron door opening of the Italian ovens is both a crutch and a huge heat sink.  Build a firebrick arch and include a thermal break between it and the entry for maximum efficiency.

[TXCraig1]

Personally, I think the cast iron door opening of the Italian ovens is both a crutch and a huge heat sink.

You can't beat the access to the oven though.

[shuboyje]

Personally, I think the cast iron door opening of the Italian ovens is both a crutch and a huge heat sink.  Build a firebrick arch and include a thermal break between it and the entry for maximum efficiency.

You can't beat the access to the oven though.

I agree with both of you thats why I spent so much time during my design and research coming up with a compromise that would give the access I wanted with a design I could live with thermally and structurally.  I personally am very happy with my result, but understand the door casting was a pretty major undertaking that many don't want to do.  In the past I've thought about offering forms or completed castings to help others, but it just doesn't work on so many levels.

[kiwipete]

Personally, I think the cast iron door opening of the Italian ovens is both a crutch and a huge heat sink.  Build a firebrick arch and include a thermal break between it and the entry for maximum efficiency.

I understand what you're saying. It's just that with my last oven the dome/opening transition gave me so much trouble that I ended up casting a vent, but looking back at it, wasn't really happy with that either.

I suppose I'm just a "crappy" mason.. Hence looking for a different solution.

[kiwipete]

In the past I've thought about offering forms or completed castings to help others, but it just doesn't work on so many levels.

Funny you say that Jeff, because some time ago, I had been toying with the idea of asking you for a copy of your moulds..

But understand about it not working on many levels (e.g. like sending a completed casting by Fedex to NZ.. shudder...$$$$)

[Tscarborough]

A cast refractory arch/vent is not the same as a cast iron door that the Italians use.

[kiwipete]

Personally, I think the cast iron door opening of the Italian ovens is both a crutch and a huge heat sink.  Build a firebrick arch and include a thermal break between it and the entry for maximum efficiency.

Apart from the reason mentioned before, I quite like "fagilia's" steel door because he leaves a gap between the door and the actual dome, so that you can stuff some fibre blanket in between and alleviate a lot of the thermal problems.

[TXCraig1]

Apart from the reason mentioned before, I quite like "fagilia's" steel door because he leaves a gap between the door and the actual dome, so that you can stuff some fibre blanket in between and alleviate a lot of the thermal problems.

What are the thermal problems?

[dineomite]

Are you using anything to buttress the sidewalls? I used a sailor course on mine just because I didn't like the idea of the lateral stress on that joint that sits between the soldier and the piece that angles to the dome. With such a flat profile to the dome, I'd be concerned about there being some sheer on that joint since the majority of the stress is outward and not downward.

I understand that a sailor isn't really an option for you since the length of the brick is non-negotiable, but that's a pretty severe angle.

[Tscarborough]

Transference of heat through the metal.

[TXCraig1]

Transference of heat through the metal.

If you were solely concerned with residual oven heat, it might be a concern. For baking pizza, the heat loss is trivial. It's a small price to pay for unfettered access to the oven.

[Tscarborough]

I agree, but I like the residual heat capability.

[kiwipete]

It has been a while, but I had to wait for my entry door to be fabricated.

So here are some more pics  of where things are at now.

There seems to be some variation of thickness of the hearth bricks. Not much, but up to 2 mm, so will have to try and level it all when I set the hearth bricks on the perlcrete.

They also have a bit of a sharp edge/lip, so I"ll sand the edges, so that they are a bit smoother.

[kiwipete]

Update.

Its been slow going because I have lots of other things to do on the house at the same time.

Hearth brick cut and using sand, placed and leveled on the perlcrete base.

[kiwipete]

Sailor course in place.

I'm mixing regular brick with angle shaped ones, to keep the gaps to a minimum. Also, to save on the very expensive refractory mortar...

[kiwipete]

Entry door in place.

[kiwipete]

Mortaring the sailor course extension bricks (angled) in place.