WFO in Utrecht, the Netherlands

[Gulf]

This devise will do nicely for your lower temp firings. I have found many uses for it. From drying out a new or damp oven, adding a little extra temp for an oven on the decline, to live fire cooking. I have plenty of pics of it in use for cooking. However, this pic is not of food. It is of the rapid drying of processed clay for the "home brew".

The device is a stainless steel charcoal chimney starter. I use lump charcoal. Start it outside the oven, puts out plenty of heat, and no direct flame impingement on the dome.

[Mr. Slowhand]

Bear in mind that this type of heater is not designed itself to withstand higher temperatures. Just the insulation on the wires and the lead are vulnerable.
Just as there are safety problems with using a home gas burner, the reason we've agreed not to discuss them, so to an electric heater that's not designed for this purpose. Far safer and more instructive to use wood. BBQ fuel which doesn't produce flames like wood is also useful for reducing flame impingement on the dome.
Here's the recommendation for the drying fires for my ovens, but bear in mind they smaller and are cast, not brick and therefore a lot thinner so the times and amount of fuel required will vary from oven to oven as well as the quantity of water that's required to be driven out.

Driving off the moisture

Day 1: 1 sheet newspaper and half a dozen small sticks, 1 h’ful of heat beads (about 5 mins of flame)

Day 2: 1 sheet of newspaper and about 10 thicker sticks, 2 h’fuls of heat beads (about 10 mins of flame)

Day 3: Bigger sticks, plus 3 h’fuls of h’beads (about 15 mins of flame)

Day 4: More wood, plus 4 h’fuls of heat beads (30 mins of flame)

Day 5: wood plus 5 hfuls of h’beads (45 mins of flame)

Day 6: wood plus 6 h’fuls of h’beads (1 hr of flame)

Day 7: wood plus 7 h’fuls of h’beads (1 ½ hrs of flame)

Clear, fully. I was thinking more of some sort of heat resistant heater, but the fire is also OK,

Thanks!

[Mr. Slowhand]

Huston, we are vertical!!!



The build is going great!. Yesterday was one of the most productive days.
I used a wire wheel mounted on a drill to clean the inside walls, and managed to lay approx 2.5 rows (3 rows over the entrance arch, as there was a gap), plus 2 on the entire one

Also started to taper the bricks, avoiding as much as possible the "wee" joints



My son adores working on it, looks quite adept as well!.

So, for tapering and other compound curves, using a clamp

[MarkJerling]

Looking good! And nice to see your son helping. My son dug the foundation for our oven, but he was 18 at the time so made short work of it!

[Mr. Slowhand]

So, finally some progress, Actually, I need to catch up with posting





Everything was going good until the 2 before last rows. In that row, a couple of bricks "escaped" and ended sliding down some half a centimetre. Not a big problem, just looked crooked. After I cleaned it it did not look that bad, decided not to do anything on it.

[Mr. Slowhand]

And, then, there was the dome completed!!!







It was a tough one to complete, but all good!



The keystone had my wife's and my name

Looks pretty ok, once cleaned up

[Mr. Slowhand]

I spent some time making the entry. After reading the comments, decided to make a big(ger) than usual entry, while still having the heat gap






The heat gap is 2.5cm

[Mr. Slowhand]

I finished, the entry, and made it with the bricks going over the ege of the entry arch

[Sixto]

Nice work! Keep it up!

[Mr. Slowhand]

so, as I understand, the idea is that the chimney opening in the entry arch is 2X of the surface area of the chimney. In my case the opening for the chimney is some 3X of the surface area of the chimney pipe. Should I decrease it, by adding some bricks to the middle opening?

Hope to start with the chimney work tonight!!

[david s]

What you have is fine. A smooth flow of smoke from the gallery to the flue pipe helps enormously. This is already partly achieved by the arch of your gallery, but a reduction of area between the gallery and the flue pipe to create a smoother flow is better. This is not as easy to achieve using brick units as it is by casting. Also bear in mind that placing too much more weight on top of the gallery increases the sideways thrust on its arch. Let the pics tell the story.

[Mr. Slowhand]

What you have is fine. A smooth flow of smoke from the gallery to the flue pipe helps enormously. This is already partly achieved by the arch of your gallery, but a reduction of area between the gallery and the flue pipe to create a smoother flow is better. This is not as easy to achieve using brick units as it is by casting. Also bear in mind that placing too much more weight on top of the gallery increases the sideways thrust on its arch. Let the pics tell the story.

David,

Thanks. Cannot delve now into casting, so will have to resort to using firebricks, although, casting would be my preferred route. I thought, as the funnel does not need any thermal mass, I can save on the width, and lay the bricks as shiner, instead of stretcher. I think I would make max two/three rows of shiners above the top of the arch of the gallery, in order to make the base for the anchor plate.
Is there any reason I should not do shiners. I see a lot of flue constructions with normal stretchers.
As regards the outward pressure on the arch, I might double the walls, as sort of buttressing

Anyhow, hope to finish this soon, than we go to isolate. The morgan rockwool is delivered, and the vermeculite also, fun times ahead!!!

Marko

[Frenchie]

Nice build, just stopping in to say it’s enjoyable following your progress, thanks for documenting and sharing.

look forward to seeing it complete (if a project is ever truly complete)

[Sixto]

so, as I understand, the idea is that the chimney opening in the entry arch is 2X of the surface area of the chimney. In my case the opening for the chimney is some 3X of the surface area of the chimney pipe. Should I decrease it, by adding some bricks to the middle opening?

Hope to start with the chimney work tonight!!

Beautiful work! I don't think you need to reduce the size, it won't probably improve the draft. For me it the solution was a compromise between minimizing weight on top of my arch, have a big enough opening, and being able to span the opening with shaped bricks to make the flow as smooth as possible. My arch is quite different than most (taller, wider, deeper) but here is how I shaped the bricks spanning the 12' x 8" opening in the arch....I am trying to do something like David's Option 3. Took me two days to cut/grind 12 bricks, I'm just showing the inner 8 ....the outer 4 just have a simple arch cut out. Each brick bears 3" on the arch, plus I'm hoping that by mortaring these 8 into 4 pairs, the installation will be easier, since the outer half of 4 of the bricks are not totally cantilevered into the opening..

Photos added for reference, (Center photo is quite distorted due to the wide angle shot) and yes I need to fill some major gaps

[david s]

That looks like an excellent solution, although I’m not surprised it took you two days. Just to make you feel worse, it takes me 45 minutes to mix and lay up a flue gallery casting and because it’s one piece and fibre reinforced, is probably stronger than one made of individual bricks.