New 36" Pompeii at Bundaberg

[brickie in oz]

Re: New 36" Pompeii at Bundaberg

How does it vent with the cap on?

[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

[cobblerdave]

Re: New 36" Pompeii at Bundaberg

Gudday

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

Regards dave

[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

[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 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.

[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

[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).

[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.

[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

[Gulf]

Re: New 36" Pompeii at Bundaberg

Nice work Steve,
I just have a couple of concerns. The vent being made of aluminum and the size of the opening.

I think aluminum can degrade over time where it is in contact with some cements. Also, I think that you could get away with a lot smaller opening for your vent. One that would be less conspicuous. I just installed mine yesterday. I only have a 1" threaded female pvc sleeve exiting the final render. My thoughts was to have a vent that could that could be plugged and be almost invisible when not needed. Look back on Dave's reply above.

[david s]

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

Looks good to me Steve. I think that the problem of the outer shell cracking is caused by large amounts of steam creating pressure. A vent can go some of the way to relieving this, but steam will still have trouble finding its way through the vermicrete to the vent. I've found that once you get the oven dry any subsequent rain and moisture take up by the insulation layer is dealt with quite adequately by the vent. A hand held to the outside of the oven can be a great indicator of the dryness of the insulation layer. If it is moist it makes the outside of the oven hot, rather than just cosy warm (in my ovens at least) depending how you have done your insulation and how thick it is, this may vary.

Dave

[Greenman]

Re: New 36" Pompeii at Bundaberg

Thanks for the advice Gulf and Dave. On second thought I have gone down the trail of the PVC fitting with cap. Pretty much out of sight up there.

Put the textured stucco coat on the base while I wait for the dome to cure. It is a bit of hurry up and wait for a while.

Give away to a good home - one miniature flue cap or large vent with cap!

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

[Greenman]

Re: New 36" Pompeii at Bundaberg

Practical Completion! Finally the last tile and the texture coat on the dome. The next project is to extend the patio to cover this. After being haunted by the aluminium vent cover I made and could not use I ended up installing a poly fitting for the vent and later adapted the vent cover to fit over the poly cap (with a hole in it) to act as a cosmetic cover.

The project has taken me 3 months all up including 3 weeks down time for a bit of minor surgery. The cost is $1200 excluding the 14" brick saw that I bought for the project. I was lucky to find cheap firebricks so that reduced the cost significantly.

I have been using the oven and am surprised by the fact that it holds the heat for days and am very pleased with the food cooked in it. It has opened up a whole new world of cooking for me and the next challenge is to make some good bread.

As I bought no particular skills to the project and learned as I went with the benefit of this forum and the generosity of those of you who offered the benefit of their hard won experience, it has been a very satisfying experience. A big THANK YOU to all of the WFO'ers that provided this guidance. My satisfactory progress is testimony to the value of the forum and it really is the epitome of peer support for a fairly complex job. It shows what can be done with some determination, an eye for detail and an open ear.

I have attached the pics of the last of what will be Stage 1.

Cheers and thanks again ........... Steve

[cobblerdave]

Re: New 36" Pompeii at Bundaberg

Gudday
Congrats .... Love that dome , must be near on perfectly round and that texture coat softens any hard lines. Like also the tile surfaces on your tops again the use of the random tile breaks the hard lines and softens the effect.
Hope you keep posting the next stages of the outdoor area
Regards dave