36" Pompeii Dome - Thailand

[UtahBeehiver]

6" is adequate for a 36" oven and with 8" you will have to flare out the opening to get the adapter plate to fit. Even the 6" the vent opening will require a little adjustment.

[Yokosuka dweller]

Hi Danhem,

Man you're progressing fast. I guess that's one of the good things about the covid situation, that we can spend a lot of time on different 'home improvements' such as especially a WFO!
I'm not sure March 2021 will be back to normal, but when...that's anyone's guess.

On chimney, I looked around a LOT here in Japan. And they do have local manufacturers of single and double walled chimneys, but none have the traditional anchor plate probaby beacuse masonry work is uncommon due to the earthquake prone region this is. There are work arounds for that, including welding your own, casting one (which would be easier and which DavidS has advised on also in several threads), or even doing a brick flue. But that would be very heavy and require additional buttressing. I didn't have that space, so eventually bought one over amazon from the US. I chose a Selkirk because they had 6" size, and the anchor plate was relative easy to get but not cheap. I got a 24" flue and it draws well enough even though it is far from the recommended height of 4 feet. So now, because I am planing to build a shed style play room around the oven, I bought another flue piece also on amazon to enable a higher roof structure. That might take a long time to arrive, but eventually it will I hope.

For Thailand, I imagine it will be difficult to source and customs there sometimes take international packets hostage for large payouts. But i found this website: https://pizzaoventhailand.com/ In English. try to give them a call and see if they can source a chimney or even if they have some handy. Otherwise, since labour is not expensive, I can imagine it would be possible to get one welded from the ground on up, if you got the right measurements, and you have someone who does good TIG welding. Let me know if you decide on that and I can share some dimensions. You also have to decide on single or double walled. Latter is more expensive but is said to draw better, doesn't heat up the surrounding bricks at the foot of the chimney and therefore doesn't risk cracking that part of the oven. Single wall is a lot cheaper and could be any kind if stainless pipe of the right dia.

[danhem]

.......including welding your own, casting one (which would be easier and which DavidS has advised on also in several threads), or even doing a brick flue. But that would be very heavy and require additional buttressing.

Thanks for the options, it seemed that purchasing the plate and chimney were probably my easiest option but will now explore the others.

Otherwise, since labour is not expensive, I can imagine it would be possible to get one welded from the ground on up, if you got the right measurements, and you have someone who does good TIG welding. Let me know if you decide on that and I can share some dimensions.

The dimensions would be great if you have them handy. I'll take the advice of UtahBeehiver and go with a 6". I had mapped out 50sq inches to accommodate an 8" chimney - from my reading I think the larger vent opening will be fine, so I should be good to go with the 50sq inches as planned.

The dimensions will help with my decision process for sure. Labour is indeed cheap here however the language barrier is always a problem and as you know the Thai way of doing things is the ONLY way of doing things. So even if my wife explains with the aid of diagrams and dimensions, the welder will always know best But definitely an avenue to explore.

Thanks again for your input and suggestions, I made progress with the ceramic rope yesterday and the service a TrueSeal seems quite approachable for standards over here.

As an aside - my neighbour who has helped with parts of this build worked for Nissan in Japan. He tried his hardest to retire out there as he loved the place so much but had a many number of hoops to jump through proving almost impossible. Your a lucky guy to be living out there, just something about Japan that is highly appealing.

[Yokosuka dweller]

Ok, I am attaching a couple of photos here with some dimensions.

Sure the easiest way will be to get a selkirk or duravent sent over, even if you know someone in the states or the UK that can send it. Not cheap but much less trouble than having to make a chimney from the ground on up. Although that option could be interesting/fun to try to do.

If I were to do that, I'd probably do the anchor plate with the chimney in one piece. So then you'd have a square stainless plate in the right dimensions with four screw/bolt holes, and one 6 inch dia hole in dead center for the smoke to pass through, that would be plasma cut probably. Then the inner flue liner/pipe would be tig welded to the edge of that hole. Should be no more than 0.5mm sheet metal pipe, definitely should be 304SS, I think even 430SS would degrade too fast. Then outer shell pipe also 304, when you look at the photos, would be about 2,5 cm wider on each side, i.e. around 8"/20cm dia...then weld that to the anchor plate as well. Make sure it's dead straight, and then fill perlite or other high temp insulation in the hollow between the pipes. Then weld it shut up top. And, adding to that make a simple 'Chinamans' hat top welded to it. Probably more trouble than it's worth, but an option if it is impossible to get a chimney pipe sent to Thailand.

Yes, Japan is not easy country for retiring, even we pay into the retirement/social insurance for years, the prospects of getting much out of that are not good because there is a huge elderly population here now that of course is entitled to pension payments. It's almost like a pyramid scheme, and I have not found a good solution to when I retire although I am hoping some long-term investments will help. I'm originally from Denmark and am playing with the idea to return to that part of the world some day, not easy though these days. But Japan is beautiful and most things work well here. I find Thailand more laid back, gregarious people, great food and you get much farther with your budget there than in Japan, especially if you can stay away from the rat race and pollution of the big city.

[danhem]

...but much less trouble than having to make a chimney from the ground on up. Although that option could be interesting/fun to try to do.

I think I’ll probably attempt this with a local supplier. My wife seems to think the guy who did our guttering will be able to help with this.

ill work to the dimensions you sent and I think it should be achievable.

out of interest do you know the dimensions of your anchor plate?

thanks again.

[Yokosuka dweller]

I don't have the paper that came with the anchor plate which had the exact dimensions, but you can also see them here:

https://www.northlineexpress.com/6-s...t-ap-5340.html

Anyway, if someone's welding an anchor plate, then I guess it doesn't have to exactly follow these dimensions - whatever way you or the welder can design a link between the anchor plate and the pipe.

[danhem]

I don't have the paper that came with the anchor plate which had the exact dimensions, but you can also see them here:

https://www.northlineexpress.com/6-s...t-ap-5340.html

Anyway, if someone's welding an anchor plate, then I guess it doesn't have to exactly follow these dimensions - whatever way you or the welder can design a link between the anchor plate and the pipe.

You have been a great help with the links and suggestions. I've explored a couple of options - 1) Custom fit with a local metal works company 2) Contacted the Pizza Oven company website.

Both options are positive and I've have quotes from both sources. Total cost for doubled walled SS 1.5 meter insulated chimney with plate and hat is around $300. The local metals works would weld the bits together, which would be the better option, however I'll probably go with the Pizza Oven company as they are more likely to understand my exact requirements.

Hope to take delivery of the chimney some time next week.

[danhem]

Outer arch and vent opening done. Can't seem to make this build pretty regardless how much effort I put in but the arch seems locked in solid enough so I'll take some pleasure out of that and move on with a touch more experience under my belt.

Looking at ordering my chimney tomorrow so whilst waiting I've been looking at how to transition from the vent. At the moment the vent opening presents around 60 sq inches.I am thinking of building up on top of both the inner and out arches to try and connect over the vent opening somehow to position the anchor plate on top. Still trying to figure it out but made a start on some cuts today that may be a good starting point.

[Yokosuka dweller]

Looking good danhem. Only point of caution is if, potentially, you might run into some constraints when fitting the anchor plate. I can't see the flue opening dimensions from your photos. Overall 60sqi is good, I think. But given the standard anchor plate is square it might constrain that down a lot because your flue opening is so rectangular. I don't know about semi arch openings, so it may not be an issue at all. Alternatively one option to increase the 'squareness' of the opening could be to very carefully grind off an inch or so at the inner arch overhang. But yeah, check this on other builds in the forum. Some people also speak of a venturi effect, so even if your opening is less than the required area, as long as your chimney maintains the required sq/area you might be fine.

Btw, I'm glad to hear you found a good option with that pizza company, yes, you are probably avoiding some potential trouble and miscommunication pitfalls by not going with the local welder/metal works option.

[danhem]

Looking good danhem. Only point of caution is if, potentially, you might run into some constraints when fitting the anchor plate. I can't see the flue opening dimensions from your photos. Overall 60sqi is good, I think. But given the standard anchor plate is square it might constrain that down a lot because your flue opening is so rectangular. I don't know about semi arch openings, so it may not be an issue at all. Alternatively one option to increase the 'squareness' of the opening could be to very carefully grind off an inch or so at the inner arch overhang.

Yes I will be looking to square the arch off as I go vertical - just trying to work out how the arch can go upwards to form a flue gallery. Seems like JRpizza and RandyJ had a similar issue to over come in their builds.

I realized after completing the vent opening that the depth is right on the button at 6” so a little tight and a definite over sight. I’ve been so careful not to make any stupid errors all the way through the build and leaving the vent right is an error.

I have plenty of width room to allow for a narrowing into a square as I go upwards. It will reduce the area dimensions but again I think I have a lot to play with there for a 6” flue.

I plan to grind an angle on the outside edge of the inner arch to aid with smoke flow into the vent chamber so hope to gain some more depth space during that process.

Eventually I hope to create a square vent chamber for the anchor plate to sit on. Not sure how I’ll do that but running with some ideas on that at the moment based on inspiration from an number of builds.

This seems to be the last real hurdle before insulating the outside and setting the curing process into action.

[Yokosuka dweller]

I had similar issue where my vent opening was a bit too tight but on the sides, not front to back. When my anchor plate arrived I scribed the circumference onto the bricks and used angle grinder to get a roundish transition. As you said you're going to have 1,5m chimney, so with that length it should very well.

[danhem]

Got my vent figured out and bricks cut into place. I am waiting for my chimney to arrive so have not stuck anything in place yet incase I need to make adjustments for the anchor plate.

I had to cut some notched bricks to create a rectangular chamber of sorts as my vent opening was formed by the arch making it difficult to work upwards. The notched bricks make the arch work vertically before the rectangle chamber is closed into a 6inx6in square with some angled cuts. I'm hoping my anchor plate will sit snugly on top. I do have some wriggle room so am confident that I can slot things into place.

I began to grind an angle on the lower outside of the inner arch to encourage smoke flow upwards. I don't have much of an idea on how well my current set up will draw but pleased nonetheless that I'm getting very close to the end of the brick work.

[danhem]

Finally took delivery of my chimney flue and anchor plate, a custom job and a pretty good effort I think. It was a month in the making so I had plenty of time to cut bricks ready to stick in on arrival.

Knowing that the refractory mortar used for the dome build is likely to fail me a some point, I have been on the look out for home brew ingredients. Thankfully another forum member based here in Thailand has only recently sourced the hard to find hydrated lime and has been kind enough to provide a 25kg bag (big shout out to SvH for this).

I wasn;t overly happy with the look of my outer arch and got sick of hanging around whilst waiting for the flue to arrive, so decided to put the home brew to its test and ripped down the arch (I was pleasantly surprised at how much force was needed to break the arch with the refractory mortar, it leaves me with a little bit of hope that the dome will hold) and rebuilt with home brew. Also filled in the gaps between bricks on the outside of the dome with home brew. Boy do I wish I'd had this stuff from the start of this build.

Built up the vent chamber and installed the anchor plate. I went with UtahBeehiver's anchor plate fixing by sandwiching the plate between bricks.

I let the brew set a couple of days under plastic wrap before sliding the flue over the anchor extension to look upon what has been in the making for some time. I'm pretty happy with the way it has turned out and it feels like a huge milestone complete as I don;t think i'll need to cut any more bricks.

I have purposefully left enough space to allow for the flue to be removed. I'm concerned about high winds and with 5 months of monsoon around the corner I will wrap the oven tight after the curing process to protect from the weather. I will have to look at the best options to secure the flue from the elements going forward but at this stage the removable flue seemed to be the best step.

Plans to insulate and lath this week before starting the curing process and tidying the odd jobs up such as mortar cleaning etc.

With any luck we may get a pizza cooked before the weather comes in or my dome caves in!

[UtahBeehiver]

Caveat Emptor, this is where we see a lot of builders get impatient. They cure their ovens too fast and too hot and crack them. The turtle wins the race in curing. You can start with charcoal briquettes (cook something while you at it) maybe a couple times. This heats the oven to about 200-250 F, then really small fires, one extra piece of wood can really spike the temp on the dome almost immediatedly. If you are seeing steam, you are running too hot too fast. David S suggest placing plastic over the insulated dome and if their is condensation forming then oven still is wet.

[danhem]

Insulated and chicken wired - damn horrible job, probably the least enjoyable part of this build. What followed later in the day however was the first curing fire and that made up for the morning shift.

Its humid here with sporadic heavy rains. I've tried my best to cover the oven dry but the under oven ceramic FB has sucked in water. I set a small fire with BBQ briquets. I use these for my home made tandoor oven. I lit a couple of briquets and expected the oven to fire up to 200F quickly. In the tandoor after an hour a pile of these briquets with hit 900F without trouble.

An hour in the pompeii after slowly adding briquets the doe hit 130F. Careful not to push to hard too fast I added more fuel without much gain. I concluded at that point that moisture and humidity must be my enemy so let the fire burn with the occasional addition of fuel. Over 2 hours later the internal temp began to rise rapidly and some areas of the oven hit the 200F mark. I moved the fire to cooler parts and once they hit temperature pulled the blaze and let settle for another day.

Its amazing at even these relatively low temperatures to feel the moisture coming off the bricks.