George's Pompeii progress

[gjbingham]

Re: George's Pompeii progress

Hey! No rain! Back to work!

Here's yesterday's progress:

Two rolls of blanket got everything covered to a 3 layer thickness, except for about a four square foot area on the back side, which has just two layers. For whatever reason, it seemed like the top of the dome was more important to insulate, so I managed to get four inches of thickness across the top, and in one area, five.

I lit a fire immediately after putting on the blanket, then started putting on chicken wire, which I felt would be easier to work with than lath. Maybe I should have waited for the fire 'cause I was eating smoke from my chimneyless oven the whole time I worked on the top of the dome.

It turned out that I tightened down the chicken wire too much, so that there was no space for the vermiculte/concrete mix. The wire holds it in against the blanket rather than acting as a scaffold to for it to adhere to. I ended up going back and loosening it all up a bit and put on an inch or so (two in the back and on top).

The vermiculite layer seemed a bit excessive considering the amount of blanket I had on there. I'm still thinking of doing a stucco finish, and for that reason alone, it seemed that the firm layer of insulation would be easier to apply the stucco to.

My arms were completely worn out after this work. Seemed like I spent the whole day laboring with my hands above my head. I'm sure glad I don't do this for a living!

Anyway, except for some small areas at the front that didn't get covered (and likely never will), this step is complete. The stuff is pretty well set up this morning, and no rain in the forcast for the next few days! The oven seems a hell of a lot bigger after all the insulation. From the other side of the yard, it really does kind of look like a big bug sitting out there. Maybe I'll do the VW finish...

I sure wish my chimney would get here. I got the wall strap and chimney cap yesterday. The other parts are yet to ship, so I'm kind of spinning my wheels again...... Back to curing the thing I guess. I've had four fires that were hot enough to make my arms hairless. I've still got steam and sweat coming out, and the dome isn't getting that hot, even after an hour of fire.

Anybody else experience this? Without a door, the morning burn, (till about 11:00 AM), my oven had cooled down to probably 150 - 200 degrees by mid-afternoon. I was expecting better than that after putting on the insulation.

From what I've read, it sounds like it takes many fires to finally drive out the moisture, and at that point the oven gets easier to heat and will hold the heat better as well. I'm resisting the urge to build an inferno in there, which would no doubt have the same result, but might be a bit too hard on the mortar joints.
G.

[Frances]

Re: George's Pompeii progress

Hey George, cool! Looks like you made the absolute most of the break in the weather.

I dunno about the inferno. I thought you were about finished with the curing, so maybe that's just what the oven needs now?

I'm happy for you that you managed to get some more work done on it anyway

[gjbingham]

Re: George's Pompeii progress

Thanks Frances. I'm still watching your progress too.

As far as curing, I took it to the five logs-plus stage, several times, trying to get past the point where I thought freezing temps would hurt the oven. Then I relaxed a bit.

I did another today and got the top 1/3rd of the dome to burn clean, which is an improvement. A couple hours later, its probably hovering around 300 degrees. I think a couple of more burns at moderate temps and this thing's going to be ready to go.

George

[gjbingham]

Re: George's Pompeii progress

Two more fires.......

One of these days I'm actually going to cook something in this behemoth.

I think the oven is about completely cured. I got it burned clean down to the second course of brick. A couple of nasty looking vertical cracks are evident in the back, about 90 degrees apart from each other. Only one is visible at all out of five pics that I took. They seem to tighten right back up as the oven cools. They appear to be about a millimeter or so in width. Nothing serious (I think?) I'm betting there's at least a couple more in there that I cannot see.

The insulation blankets and vermiculite seem to hold in all the heat. I cannot feel any sign of warmth on the outside of the insulation. Absolutely cold to the touch. The disconcerting part is that the oven still cools down pretty quick. 12 hours later, with the vent and door covered as well as possible with boards/bricks, the oven is probably at around 150 degrees. I was hoping for something better. Perhaps a real door? I guess that's where I'm headed next.

Regardless, my chimney is supposed to ship today, so in a week or so, I'll be in the final stretch.

[asudavew]

Re: George's Pompeii progress

First of all... Outstanding work George!
You got that puppy humming!

One of these days I'm actually going to cook something in this behemoth.

2nd - You need to be putting that heat to good use, and practicing your mad bread skillz.

I think the oven is about completely cured. I got it burned clean down to the second course of brick. A couple of nasty looking vertical cracks are evident in the back, about 90 degrees apart from each other. Only one is visible at all out of five pics that I took. They seem to tighten right back up as the oven cools. They appear to be about a millimeter or so in width. Nothing serious (I think?) I'm betting there's at least a couple more in there that I cannot see.

3rd - My guess is that if they don't get any worse after another couple of plasma fires, then they probably never will! No worries~

The insulation blankets and vermiculite seem to hold in all the heat. I cannot feel any sign of warmth on the outside of the insulation. Absolutely cold to the touch. The disconcerting part is that the oven still cools down pretty quick. 12 hours later, with the vent and door covered as well as possible with boards/bricks, the oven is probably at around 150 degrees. I was hoping for something better. Perhaps a real door? I guess that's where I'm headed next.

4th - I think you have plenty of insulation.
But... what are you using for a door? Have you tried blocking it off with leftover bricks?
Also, how long are your fires burning? If you really want some leftover heat the next day. You need to burn long and hot. 2 hours seems to work for me, but you have more insulation, so maybe 1.5 hours or so.
Try a 2 hour fire though, and let me know how it turns out!

Regardless, my chimney is supposed to ship today, so in a week or so, I'll be in the final stretch.

Finally - Great work! I can't wait to see the end result.
I've been spending my weekends cooking in mine, I need to get back to the "finishing"!

Dave

[gjbingham]

Re: George's Pompeii progress

Dave,
I'm firing the oven for an hour or so. I searched the forum and found some interesting posts on temperature curves during firing, and in the cooling phase. After seeing them, I think that my 12 hour temps are pretty reasonable without a door in place.

I would be using bricks to close it off, but I only have 2 whole bricks and a bunch of pieces left out of the original 200. I think I wasted about 20 along the way, mostly around the dome/opening transition.

My first cooking will be both a pizza and bread bake. I need to get the door issue ironed out first.

[gjbingham]

Re: George's Pompeii progress

Still working the door issue. Walt, my neighbor who helped me with a lot of the concrete and brick work, snuck off this morning and made a door for the oven out of a 2 X 12, milled, glued and cut to the arch shape. He put some nice handles on it and left a slot at the base for O2 to get to the fire with the door in place. What a nice surprise that was to find upon returning home from Christmas shopping.

Pics tomorrow. It's almost 5 AM. I've been up since 2:00. God knows why.

One of my other neighbors is a iron worker and has a lot of his equipment at home. I'd already hit him up yesterday to cut a door from a 1/8" iron plate, to which I plan on sandwiching kaowool insulation and my new wood door. Somewhere amongst all this work, hopefully a functional door will appear.

I gave up on my internet chimney supplier. They shipped the two 48" pipes today, but after nearly 3 weeks, still did not have the anchor plate in stock. I cancelled the order and bought one from the FB store. They've already shipped it - incredible!

G.

[gjbingham]

Re: George's Pompeii progress

Hi all,
Happy holidays for everyone, I hope!

I took pics of the doors, but for whatever reason, they didn't download from my camera. I'll get back to that topic later when my insulation for the sandwich door shows up.

As I eluded to in Ken's thread about his arch cracking in the Firing Your Oven Forum, I found that my entryway bricks were being pushed outward by the apparent thermal expansion of the floor during firing. I think the major cause of this is that I cut back the vermicrete insulation under that area during my previous pour to make additional space for concrete stability under the cantilvered hearth area. The lack of insulation seems to cause differences in the way the bricks heat and cool. At least that's my best guess. I attached a pic of the 1/16th - 1/8th inch gaps in the bricks, but it's really hard to see.

I attempted tapping the bricks back into place, but the edges started to crack and crumble, so I gave up on that idea. I decided to live with the gaps and fill them in with fire brick dust, and then try to lock them in place with my final planned pour for the oven landing.

Walt made the front portion of this form out of 3 pieces of 2 X 8 glued together and then cut with a band saw. I had to retrofit rebar into the existing hearth using bolts in drilled holes. Then yesterday, Walt and I poured this little section with two 80lb bags of Quickrete 5000 and stain.

I should have mixed both bags at once because despite my best efforts to get equal amounts of stain in each batch, the two mixes came out with different shades. It will be interesting to see what this looks like when the forms come off.

Anyway, it was a coldish day. 40 degrees slowed the rapid set of the concrete down to that of normal concrete. We poured at 8:30 AM and I was finally finishing the stuff at 3:30 PM. The edging tool refused to give me good results in a couple of spots and I'd hoped to get a better result than I ended up with. Regardless, it's done. Hopefully it will hold the entryway bricks in place.

I did put rebar uprights on the sides for my next concrete work. Once I've got the decorative arch in place, I'm going to butress the entryway walls and arch with a two inch +/- wall of concrete. After picking up all 8 feet of my Duravent chimney, I couldn't imagine the vent arch holding that much weight. Hopefully, the concrete butressing will do the job.

[gjbingham]

Re: George's Pompeii progress

Rain, rain, go away.....

Work continues, slowly. Just about freezing in the morning, 10ish in the AM before I think about going outside, too dark to work at 4:00. Watch the baby, deal with life...... So it goes.

Progress pics:

-The landing turned out pretty well. Perhaps a bit too bulky, but I like it.

- Decorative arch in place, still needs a bit more style. I'm working on it.

- half-assed forms held in place by 2 X 4s for concrete butress of vent walls.

- Landing's finish ruined by scrubbing off mortar. RE-DO!

- Oven door - two views. The camera batteries crapped out on me so I lost the interior. The interior door is an iron plate fabricated by Keith, my iron worker neighbor and great guy, in the shape of the oven opening. Your imagination will probably suffice. Four 1/4 inch bolts welded in place. Wood exterior door complements of Walt, my best helper and advisor. Holes drilled through wood door, rasped by hand to fit, and space left for insulation....... still coming????? Walt is a retired fireman, and insisted that the door need a vent to keep the oven from blowing up. When you tip the door backwards towards the vent, it should allow air to enter the oven from the bottom cut out and direct smoke out the chimney.

Thanks all for your help with this awesome project. It's almost done. Most of all, thanks to James for making it happen.

Buon ano a tutti! (Happy New Year to all)

George

[Acoma]

Re: George's Pompeii progress

George, I had similar concerns about heat issues and door closures. I will likely build some type of slit, opening for the door. Your neighbor is kind indeed to offer his knowledge.

[dusty]

Re: George's Pompeii progress

For whatever reason, I haven't seen your project for a while...it looks fantastic. I need to pay more attention. The door seems really clever - what with that slit in the bottom and air space between the wood and the steel. How does it work?

dusty

[Acoma]

Re: George's Pompeii progress

George, why not insulation board inbetween the ply and steel?

[gjbingham]

Re: George's Pompeii progress

We'll see how well it works. I played almost no part in it's making. Walt made the wood portion, with the slot at the bottom. I already commissioned Kieth to make the iron door and once I saw the wood door, I figured I could sandwich them together so that when I tipped it back, it would allow for a good draft door allowing O2 to the fire, and serve as a good heat containment door when fully sealed. Kind of blind luck. The Doug Fir may just burn up, but if it works reasonably well, I'll do it again in hardwood.

Acoma, I ordered kaowool fiber for the insulation for the door about 3 weeks ago. McClendon's Hardware was the seller. It turned out that they had sold out. They promised to send it express as soon as it came in........ Santa came and went but I didn't get my insulation. It is a ceramic fiber blanket, so it may not hold up over time going in and out of the oven.

I would have used ceramic board, but it is more expensive and I only need a small piece. If anyone wants to split the cost of one and cut it in half, let me know. I just couldn't see spending $53ish for my small need.

G.

[dusty]

Re: George's Pompeii progress

If anyone wants to split the cost of one and cut it in half, let me know.

I'm in! Let's do it.

dusty

[Acoma]

Re: George's Pompeii progress

George, Dusty and I have extra from our ovens. Thanks Dusty, beat me to it.