George's Pompeii progress

[gjbingham]

Re: George's Pompeii progress

OK, I decided to pour the concrete up to to level of the vermiculite insulation pad. I pulled out the interior forms and hand mixed 8 bags of concrete yesterday and poured around 75% of the dome.

I'm basically killing time till I can cure my dome and I have other stuctural issues to deal with anyway. I took out the forms under the concrete hearth slab today. I had a vision of the whole 2 tons falling in on me while I was knocking out the legs under the plywood. I'm stll here! Amazing.

Still having the cantalevered entryway to deal with, I couldn't come up with any plan to pour this section than to rip up my vent/archway floor and vermiculite layer, then build new forms, place rebar in order to have enough mass sitting on the original hearth slab that the cantalevered section won't be subject to fracture. I'm just a little short of where I'd like to be to include a decorative arch out front and need more space, so I've kind of painted myself into a corner on this one. I've got to do something, I think.

So after a day of deliberation, I pulled up those floor bricks and went to work. I hit the vermiculite layer with a masonry saw blade. It went right through but left moist mud debris in the saw blade guard. The stuff is still wet in there after 3ish weeks! Regardless, I used a chisel and hammer to remove the vermiculite from the concrete slab. I comes out pretty easily.

On other fronts, I still can't remove the forms from the concrete pour yesterday so I'm waiting, less than patiently, to get going again. and frame in my cantalevered entryway.

In the mean time, I decided to do a casted vent, to which I will attach a double walled chimney,that will have to rise some 8ish feet to clear the house with 2 feet of clearance. God, this seems to go on and on.......
Pics are coming soon.
G'night
George

[gjbingham]

Re: George's Pompeii progress

OK, it's raining and I'm without meaningful work.

Here's the photos of the last couple of days work:

[gjbingham]

Re: George's Pompeii progress

Let's try that again:

So I pour concrete around the vermiculite layer to bring everything but the front up to one height. That was a couple of days ago. Only nine 60 LB bags did the trick.

I checked out Daves vent/chimney transition. He posted a bunch of great pics for me. I picked up similar hardware at Lowes but decided to try to cast a this piece to try to make it more durable. I used a castable cement with 1/3 firebrick sand from my cutting tray added to pour this thing. I'm kicking myself in the butt now 'cause I forgot to add some wire mesh or chicken wire. It may be 22 bucks down the drain.

The thing weighs a ton though. I think I'll go ahead and mount it and due my curing fires. If it can make it through several 700 plus degree burns without breaking, I'll go with it.

Today, I started work on the front. I'm just a few inches short of what I need for the entryway and decorative arch. I knew this would be an issue when I poured the first hearth slab. The time has finally come to deal with it.

As I said previously, I decided to remove some of the vermiculite to increase the surface area of the new concrete pour sitting on the first hearth slab. I used a masonry saw blade and hammer/chisel to remove as much as possible.
I'm working on the forms for the next pour when the rains allow.

You can see the oven is occluded and I have a space heater in there that I turn on for about an hour or so a day.

The last pic shows the sun exposed side of the dome, shot today. The cladding is dry, but you can clearly see the moisture lines in the mortar joints. Even the short heating periods I've been putting the dome through have had no significant effects on these moisture lines. The soldier course mortar joint are getting close to 3 weeks old and are clearly present. Four more days, and it's time for fire!

That's it. I'm up to date. Next, I pour the front, reset the entryway floor that I tore up, then build some arches and vent.

George

[Ken524]

Re: George's Pompeii progress

Great idea to use the Lowe's vent as a casting mold. Curious to see how it takes the heat!

[Frances]

Re: George's Pompeii progress

I didn't put any wire mesh in my vent either, because the mortar started flowing all over the place as soon as I touched it. Hasn't falled down so far...

Are you going to remove the metal bit inside the vent or leave it in there? it looks really good btw, creative way to get the form you need.

What was the vermiculite like when you cut it off? Because lots of people have said it was still wet inside.

[asudavew]

Re: George's Pompeii progress

Great idea to use the Lowe's vent as a casting mold. Curious to see how it takes the heat!

Yes it is! I can't wait to see how this turns out George.

My system, to put it bluntly, sucks. Well actually it doesn't suck.

It heats up quickly, but it cools quickly if the fire dies down a little, so I don't get a consistent draw. - i.e. Smoke in Dave's face, eyes, nose, ears... etc.

[asudavew]

Re: George's Pompeii progress

I used a castable cement with 1/3 firebrick sand from my cutting tray added to pour this thing. I'm kicking myself in the butt now 'cause I forgot to add some wire mesh or chicken wire. It may be 22 bucks down the drain.


George

Where did you find castable cement George?
I think I am going to copy you on this one!

[gjbingham]

Re: George's Pompeii progress

I'm back with answers and observations.

Frances, yes. The Vermiculite was still moist inside. The dust from cutting it turned into mud in my blade guard and got so think that the blade was having trouble turning. I had to stop and clean the thing out. The Vermiculite comes out really nice and clean wit a chisel though. The saw would only cut to a depth of two or so inches, so I had to dig the rest out.

Re. the vent, I think I would need tin snips to get it out of there. It's rivited and has rough/loose edges, so I don't think it is just going to fall out of there.

Dave/Ken - The lightbulb went on over my head while I was looking at that vent at Lowes. I remembered seeing the pics of casted vents in the photograph sections. I think 24ish years of dentistry has something to do with the idea. We dealt with things like this on a miniture scale all the time.

As I poured the concrete landing area this morning, I noticed minute cracks in the vent casting. I'd forgotton to cover it with a wet cloth! What a DS I am sometimes!
Anyway, I covered it and will ignore the fact that it may be a failure, for the time being.
BTW, I got the cement at Lowes. $14 for about a 10 LB box, 20 for a 50 Lb bag. I think it's called Cementall or something similar. It said it was castable and has a really fast set time. As I said, I added 30% firebrick sand from my saw's water tub.

We'll see how that turns out. I'm on hold for a couple of days waiting for the new pour to set before I reset my entryway floor and get going on the arches and vent.

George

[gjbingham]

Re: George's Pompeii progress

A quick update:

It's been 6 days since I seated my dome's keystone, which had virtually no mortar. Seven days since I put in the previous two rows. I've had a space heater inside the dome for four or so days, gradually increasing the length of time I let it run. I put a digital cooking thermometer in it yesterday after nearly two hours of heating. It was around 120 degrees, plus or minus a few.

You can see my new concrete addition to the front of the structural hearth and the dome's opening occluded by bricks. BTW, I wouldn't recommend fully closing off the dome like this while running a space heater. The dome just sweats buckets. You can see rust stains from the angle iron on the entryway floor in the following photos. Most of the mortar joints are still clearly moist. More freezing temps will be here soon so I really want to get this thing cured over the next week then just keep it as dry as possible until I can insulate and seal it.

Enough messing around! The weather plain sucks today. Rain and a big windy blow this AM kept me in the house. As soon as I saw a break in the weather, I went out and pre-heated the dome with the space heater in order to minimize the rapid change in temps during a 200 degree curing fire. (I decided to skip the plain paper first burn due to the space heater use).

Just a few cedar shingle pieces and a couple of wads of paper. The fire got a little big, so I pulled about half out (better safe than sorry) and let it burn for about 7 or 8 minutes. It sure felt like a 200 degree oven at the top of the dome.

Not too exciting, but it's a start. Tomorrow, weather permitting, I'm back to working on the entryway arch and vent.

Dave, just a note about the castable refractory material. I saw in someone else's thread, a discussion about needles used in castable material to minimize cracking. It turns out if you do an ebay search for refractory, or castable refractory, you can probably find a better solution to your oven.

George

[asudavew]

Re: George's Pompeii progress

Thanks George.

I really need to do something. The setup I have is too small and light weight.

Still deciding.. But I didn't know Lowe's carried that castable cement. That is probably the route I will go.

[gjbingham]

Re: George's Pompeii progress

Dave,
Well don't forget some kind of wire mesh or something to eliminate cracking.
G.

Nice post on the Chicken Farm. I just read that earlier.

[wlively]

Re: George's Pompeii progress

Dave if you are going castable make sure and get refractory castable. I used KS-4. And also get the stainless needles.

[asudavew]

Re: George's Pompeii progress

Thanks guys!

[gjbingham]

Re: George's Pompeii progress

Another quick update.

The casted vent is still in one piece. I didn't take a photo of it yet. We've yet to see if it will withstand the heat from the oven. If not, I guess I'm stuck buying some castable refractory material, or doing it the way Ken posted recently his pic posted on the Photo Forum. That's a really nice solution to the transition to the chimney, and probably easier than my route.

I'm doing two fires a day in the oven. First thing in the morning, then late afternoon, when the brick has come back to ambient temp., or at least till it's not warm to the touch. It cools pretty fast so far without any insulation, though the hotter it gets during the curing fires, the longer it takes to cool. I figure I've got the oven up to about 400 degrees F so far. I'm trying to err on the low side rather than push it too fast.
In the mean time, I set the brick for the entryway floor and layed the brick for the entryway walls this afternoon. I will probably not go much further with the curing fires for the time being as my new brick and mortar will need time to set and cure on the new walls. I'm happy with it so far, but I'm kind of stuck waiting on the the arches, as I want to get the dome cured as much as possible (before the inevitable freezes coming) and before I put in arch forms in the entryway and block any chance at finishing the cure of the oven for the week or so that the arch forms are in place.

That's probably it for the next week or so I figure. It's getting twilight around 4:45 PM these days, so the working time available is dramatically shorter since I can't force myself out there at 39 degrees in the AM without good reason.
Anybody else suffering from the cold??

George

[Frances]

Re: George's Pompeii progress

"Anybody else suffering from the cold??"


Yep. I'm completely stuck on my oven, due to freezing temperatures for the next... dunno, weeks? Ok, so the oven is cookable in, and safe for the winter. Which is cool. But I want to go out there and slap some cement around!! No idea how I'm going to survive the winter... I'll probably have to take up needlepont or something

All I can say is, its lucky I'm the patient type... (like so many others on this forum, yeah?

...is that the kind of suffering you're talking about? Or more the kind where you go "geez, but my fingers are so COOOLD!"