New 36" Pompeii at Bundaberg

[Greenman]

Greetings from Bundaberg

I am Steve and have been interested in building a WFO for a number of years. I now have the right place and the luxury of the time to get started. I have been scouring the threads and the instruction booklet for information and inspiration and decided on a 36" Pompeii. I have got as far as completing the base which incorporated a preparation bench beside it. Like most furious reading about a subject that is only being visualised there are plenty of bits of information that are missing or answers that are not fully formed. That is where I hope to get some assistance from those who have learned by doing.

Sourcing suitably priced firebricks in this part of the world is difficult and new bricks start around $5 plus freight. I found some finally about 120km away at the right price and although they have been sitting under a fig tree for long enough for the pallets to decay they are good and at 10% of the going rate they are better - they are also new which is even better. The only thing is that they are tapered 9" x 4 3/8" x 3" - 2 3/4". I also have 60 at 8 7/8" x 4 1/2" x 3" - 2 1/4".

I have a few questions that stand between me and progress at this point:

1. Is there a way to use tapered bricks that utilises them to best effect?

2. What is the optimum depth of the entry from the decorative external arch to the inside of the internal arch? The 19 x 12 entry dimensions in the plan is what I intend to use. Also, does this need to be wider as it goes out?

3. Is a thermal break outside the internal arch a necessity? If so, what provision needs to be made when laying out the floor and the flue landing?

I would appreciate any assistance you can offer.

I will attempt to add some pics of the build up to now if I can figure out how to drive this beast.

Cheers

Steve

[UtahBeehiver]

Re: New 36" Pompeii at Bundaberg

Welcome Steve,

Nice base work, clean, neat and well thought out. Where is Bundaberg, AU, UK ??

IMHO

1. Check out OASISCDM under the Australia Region thread. He is using tapered bricks in his build. I just want to make sure I am seeing correctly on the tapper. If the thickness of the brick is constant then you can use on the floor. See pic one, I used tapered brick here. If the taper is on the thickness then it may be harder to use on the floor without a lot of leveling and would be better suited for the dome and arch.

2. Depth, lots of discussion on this and various opinions. But flue size will dictate min. depth. Mine is about 14" on a 42" oven. Flaired opening, again lots of opinions. Some say gives better access. A little more difficult to build arch vs a straight entry. Mine is straight.

3. This is currently being discussed in OASISCDM thread. Check it out. I installed a 316 SS thermal break in floor and a partial air gap with ceramic fiber rope and HT caulk in mine. Pictures on my thread and picassa album

Good luck.

[fabby]

Re: New 36" Pompeii at Bundaberg

That's going well and is gonna be nice.

"Somebodies got sum game......"

[david s]

Re: New 36" Pompeii at Bundaberg

Hi Steve,

1. Maybe you could cut the bricks in half leaving you with two bricks of different widths. So long as you staggered the vertical joins on each subsequent course it could work ok with minimal cutting.

2. IMO the shallower the entry the better, providing you have adequately flued the oven, it makes it way easier to manage when firing and cooking. This is not so easy to accomplish if you build the entry with bricks though. (I cast mine)

[david s]

Re: New 36" Pompeii at Bundaberg

3. A thermal break between the oven and entry is a good idea IMO. We rabbit on about insulation yet build ovens that are thermally connected to an entry with a large mass.i raised the thermal break idea a couple of years ago, not my idea originally (I got it from Rado of Traditional Oven) if made of a flexible material it can also act as an expansion joint. If you are separating the entry from the oven then it would also make sense to separate the floor at that point too.
Because my entry is light and has small contact points with the oven I preferred to place my thermal break between the entry and the outer decorative arch. There is probably a greater thermal differential between them. I've seen lots of pics of ovens without the thermal break/expansion joint that have cracked outer arches

[Greenman]

Re: New 36" Pompeii at Bundaberg

Thanks for the responses folks. Bundaberg is about 300 km north of Brisbane in Queensland, Australia. The home of Bundaberg Rum and Mon Repos turtle rookery. I have had a brief look at the 'recommended reading' and it is fertile ground. I will spend some time looking closer. These bricks taper over the length on the flat, if you get what I mean, so I will have to cut them for the floor. I picked up a 14" wet saw second hand with a notion of selling it after the build. The best laid plans of mice and men............. Given the way the bricks taper I will end up with one half slightly thinner in profile than the other, unless I use the cut ends in. The smaller ones will probably be best used higher up the dome.

The thermal break/expansion joint seems to make good sense and now is the time to think about that and incorporate it.

It seems that there are a lot of considerations at this particular point of the construction and the end result may well reflect the decisions made now.

I made a version of the IT today which is different but should work. My twist was to drill and tap the wheel in the coaster. It needs a bit of care to get the hole in the wheel straight and square and a pedestal drill helped there. The thread putting pressure on the axle damps the movement as you like. It is completely simple but I think it will work.

It looks like we are to be blessed with a little more rain now that the floods are over so that pushes things back into the shed for a couple of days.

Thanks for the information and encouragement. I will keep posting (and asking questions no doubt).

Cheers

Steve

[UtahBeehiver]

Re: New 36" Pompeii at Bundaberg

Steve,

A new variation on the IT, creative thinking on the threading of the caster wheel. a couple ideas that may help you. Cut the all thread and add a long barrel threaded nut. This will give your IT some adjustment length. The dimensions of the build vary slightly, some case more, during the build and being able to adjust the length will help alot. Second on the wood support holding the face of the brick, taper the bottom edge about 45 degrees this will aid in moving the IT after you set the brick. A 14" swa will handle most anything you will see on your build. Good luck.

[david s]

Re: New 36" Pompeii at Bundaberg

Steve, have you tried laying the floor bricks side by side, head to tail?

[brickie in oz]

Re: New 36" Pompeii at Bundaberg

If your dome is on top or next to your nicely cut hearth bricks you are going to lose mega heat out the side of the hearth bricks where it contacts the concrete slab.
It will make all that cutting and prep work almost worthless.

I know this because my first build was similar.

[Greenman]

Re: New 36" Pompeii at Bundaberg

Russell - Thanks for the feedback on the IT. I will make those adjustments. It is the tweaking that brings things to life.

David S - The bricks are thicker at one end than the other on the flat side. They have one square side and will make a symmetrical shape if placed head to tail on their side. Looks like a cutting job to remove the taper for the floor bricks.

Al - Not sure that I understand what you mean. The vermicrete under the oven is big enough that no bricks sit on concrete and the outside of the finished dome including insulation, should just make the concrete surround. Am I on the right track or have I got lost.

Might celebrate Easter Monday by cutting the floor bricks.

Cheers

Steve

[brickie in oz]

Re: New 36" Pompeii at Bundaberg

Sorry, just re read the post, I saw Beehivers post and thought it was yours.

[Greenman]

Re: New 36" Pompeii at Bundaberg

No worries. I can only aspire to that quality of work.

[Greenman]

Re: New 36" Pompeii at Bundaberg

Had a good day with the saw and the floor bricks aren't tapers anymore and are ready to lay and enough are now cut to get the dome started. I figured on putting a thermal break outside the inner arch so I pulled the floor up there for now.

Can I get clarification about laying the floor inside the dome rather than building the dome on the floor bricks? The FB instructions talk about doing it that way but most of the pics show the dome on the floor. I have cut the bricks but it is not laid yet.

Another question I have is about consistency of bricks in the dome. I have mostly light bricks but I do have some smaller redish ones that I thought might be handy higher up the dome. Is is ok to mix them or does that create problems with different heating/cooling rates?

And finally, is it imperative that the manufactured surface of the brick face the interior of the other or is presenting the cut surface ok?

That is another load of questions but I figure it is better to ask first. Used up my quota of 'act in haste, repent at your leisure' for this life.

Your advice would be appreciated.

Cheers

Steve

[UtahBeehiver]

Re: New 36" Pompeii at Bundaberg

Steve,

IMHO, If you building and enclosure around your oven then building the dome on the floor bricks are easier since your floor cuts need not be as precise. If you are not enclosing your oven the you can go either way on the floor or around the floor but you need to factor in how the floor bricks will affect the overall shape of your oven. I did around the floor.

When I placed bricks I chose which face had the cleanest face regardless of cut or factory face. Can't comment on mixed bricks, did not use in my build.

If you have any high spots/edges on your floor you may want to use an angle grinder with a cupped diamond wheel to smooth out. This is so your peel will not catch the edge of the brick. Good luck.

[Greenman]

Re: New 36" Pompeii at Bundaberg

Thanks Russell - I will build around the floor. The floor bricks ended up very close to flat and level at the dress rehersal, a few rock on an imperfection but that will sort itself out when laid.

Onwards and upwards when I get to it this afternoon.

Cheers

Steve