New 36" Pompeii at Bundaberg

[Greenman]

Re: New 36" Pompeii at Bundaberg

Today was the day to render the dome. Looking very different in its new sarcophagus. I decided on concrete and lime mortar and a finishing colour coat of Dulux acrylic mortar in a couple of weeks when this dries. I left a small area at the top to put the vent, probably tomorrow.

Also spent some time making a vent from some patterned aluminium I had about. Have attached a pic of what I ended up with. Not particularly original, inspired by headware in country SE Asia. It is 200mm (8") across the 'hat' and 100mm (4") high and I intend to secure it under the render coat after loosening the vermicrete immediately under it a bit. With the small gap between the barrel and the 'hat' the chance of water entering should be remote, particularly with the gap ending up about 75mm above the dome.

Any thoughts about the vent before I literally set it in concrete? Your opinions would be appreciated.

Cheers ............ Steve

[david s]

Re: New 36" Pompeii at Bundaberg

Thanks David - I will give some drying time. I had a week of curing fires before I started with the insulation, do you think that some gentle firing when the vermicrete has had some drying time (prior to the outside render) would be worth doing?

I will put a vent on top, just have to decide what kind, thinking of something decorative.

Yes definitely. Cure the thing before doing the render, otherwise you've locked the moisture in and it's even harder to remove.

[brickie in oz]

Re: New 36" Pompeii at Bundaberg

Hey Al - I followed up with the alloy strap/stainless steel flue issue and you are right (was there any doubt). The combination of aluminium and stainless is a recipe for grief. I have changed it, looks better too.

Thats how they make batteries, two dissimilar metals and an acid medium (acid rain in our case).

[Greenman]

Re: New 36" Pompeii at Bundaberg

Hey Al - I followed up with the alloy strap/stainless steel flue issue and you are right (was there any doubt). The combination of aluminium and stainless is a recipe for grief. I have changed it, looks better too.

Have sorted out the door and am happy with that. The vermicrete layer is drying (isn't that wonderful stuff to work with) and I am contemplating the render for the base, some tiles for the benchtop and around the oven and which oxide to use in the render on the dome. Slowly coming to a conclusion helped considerably by good advice here.

Here are some recent pics.

Cheers ............. Steve

[Greenman]

Re: New 36" Pompeii at Bundaberg

Thanks David - I will give some drying time. I had a week of curing fires before I started with the insulation, do you think that some gentle firing when the vermicrete has had some drying time (prior to the outside render) would be worth doing?

I will put a vent on top, just have to decide what kind, thinking of something decorative.

[david s]

Re: New 36" Pompeii at Bundaberg

The curing fires are done and the coals of the last fire are on the way down as I write this. I cured the oven without the insulation. There seems to be multiple schools of thought about that but the ambient temps here are not extreme and frankly it made sense to me to have a way out for the moisture as the heat drives it out. There are some small cracks in the mortar but they have settled back to be nothing much (the pic was taken when the oven was very hot but the exterior had not saturated). The inside has no evidence of cracks.

Tomorrow I will put the ceramic 'wool' insulation on, the chicken wire and start on the vermicrete layer. I am thinking of applying the vermicrete in a couple of layers to allow it to dry more easily. Would a couple of days between layers be of use for this purpose? Also, how long is good before applying the stucco?

There has been some mention of leaving a vent for moisture to escape the dome. Would anyone care to expand on the notion?

Other than that, I used the later curing fires to cook and am happy with the results. I figure it will just get better from here.

Cheers .......... Steve

A couple of days will do little to remove the water from the vermicrete. I like to do it in one inch layers with a week of drying each. Then you can apply your outside render. Moisture in the insulation layer can create steam pressure build up and crack your outer shell. One litre of water makes over 1600 litres of steam.
A vent can help reduce this.

[Greenman]

Re: New 36" Pompeii at Bundaberg

Thanks Dave - some good information there. I put the 'wool' and bird wire on today. It is not so bad to work with but I did have the recommended PPE.

Little by little it comes together.

Hey Al - thanks for the warning about the curing fires. I intended to go steady on it for a while and do some baking and roasts. Cooked a fish in the reminants of the curing fire last night and it was prime.

Cheers ............ Steve

[cobblerdave]

Re: New 36" Pompeii at Bundaberg

Gudday

Waterproofing Dome Pompeii oven construction section
You might interested in this discussion

Regards dave

[cobblerdave]

Re: New 36" Pompeii at Bundaberg

How does it vent with the cap on?

Gudday
No it doesn't but left open to the elements all the time the local ants take up residence

Regards Dave

[brickie in oz]

Re: New 36" Pompeii at Bundaberg

How does it vent with the cap on?

[cobblerdave]

Re: New 36" Pompeii at Bundaberg

Gudday Steve

Dome cap mk 11 basically a brass water pipe end cap silastic to the dome. Hole was caste by rolling a bit of cardboard and mortaring around it . Once the mortar had cured the cardboard was wet and soggy and easy to remove. A chain has been attached to the cap and drops down the pipe so "little fingers" don't lose it.
Perhaps a bigger end fitting and cap is made irrigation pipe? , there's a bit of that in you area.
Hope this helps in some way
Regards dave

[brickie in oz]

Re: New 36" Pompeii at Bundaberg

The curing fires are done

The curing fires take weeks to get all the moisture out, dont take it too quik otherwise you may be sorry you did.

[Greenman]

Re: New 36" Pompeii at Bundaberg

The curing fires are done and the coals of the last fire are on the way down as I write this. I cured the oven without the insulation. There seems to be multiple schools of thought about that but the ambient temps here are not extreme and frankly it made sense to me to have a way out for the moisture as the heat drives it out. There are some small cracks in the mortar but they have settled back to be nothing much (the pic was taken when the oven was very hot but the exterior had not saturated). The inside has no evidence of cracks.

Tomorrow I will put the ceramic 'wool' insulation on, the chicken wire and start on the vermicrete layer. I am thinking of applying the vermicrete in a couple of layers to allow it to dry more easily. Would a couple of days between layers be of use for this purpose? Also, how long is good before applying the stucco?

There has been some mention of leaving a vent for moisture to escape the dome. Would anyone care to expand on the notion?

Other than that, I used the later curing fires to cook and am happy with the results. I figure it will just get better from here.

Cheers .......... Steve

[Greenman]

Re: New 36" Pompeii at Bundaberg

Thanks Al - will fix that so it doesn't become a problem, some s/s strap should remedy it.

Hey Dave - I hear what you are saying. A bit like beer, all good just some a bit better than others. I feel a bit privileged to have the time to just build this from start to finish on one roll and respect the tenacity of those who have been soldiering on for a very long time in their valued spare time.

There are probably lots of people who would not have the pleasure that comes with a WFO for a lot of reasons without the kits that go together quickly.

There are probably a lot of people like me who would have found building one much more difficult without this forum and the assistance it provides too.

Thanks and Cheers ............. Steve

[brickie in oz]

Re: New 36" Pompeii at Bundaberg

Steve.
One thing I did notice is the strap holding the flue up, if it is alloy as I suspect from the looks of it, the alloy will react with the stainless flue and one will become a cathode and one will become a anode, one will rot away real quickly.

Both of them need to be of the same material to avoid this.