36" Pompeii in DC

[rsandler]

Re: 36" Pompeii in DC

After closing the dome on Wednesday, while my in-laws went out sight-seeing, I started working on my vent arch. This ended up being a bit more work than I expected, and I ended up having to finish it in the evening, and left s-curve for the chimney incomplete.

Thanksgiving morning, I took a few minutes to remove the forms, and clean up the mortar from the arches and the debris from around the oven. To my everlasting surprise, the arches stayed up!



Today, with the in-laws having gone home, I finished off the chimney base, such that it's ready for a flue to go on.



I must have mis-calculated somewhere, because instead of the opening being almost 10" across side-to-side at the top, it's only a bit over 5", giving me an opening slightly larger than 5"x6"


Still, since my oven opening is just over 200 square inches, a vent of just over 30 square inches comes to right around the 15% ratio that seems to be recommended. Given that I'm planning on putting a relatively tall flue on top of the thing (haven't figured out whether to go ceramic or stainless, round, square or what), I think/hope it will draw just fine.

If I'm wrong about that, someone let me know! I could still knock the top couple of bricks off and shave them down or something.

Cheers!
-Ryan

[mrchipster]

Re: 36" Pompeii in DC

Looking vey nice, and the shirt sleeve weather is a bonus this time of year. We woke to 2 inches of snow on the grass. The snow melted off any pavement right away but the snow is still there this evening.

As you can see from the lawn mower in the back of the photo the snow was a surprise.
Chip

[rsandler]

Re: 36" Pompeii in DC

Well, I started curing fires this week. Started off Tuesday by burning newspaper, and slowly worked my way up through twigs, branches and logs over the next few evenings. Last night I had a couple of logs burning off and on for about 4 hours, and had the floor and walls hovering around 300 most of the time.

This morning I put the InsWool insulating blanket on and tied it down with rebar wire. At least 3" all around, with 4" in most places and 5" at the top. This was perhaps a bit pre-mature, as towards the end of todays fire (going for around 3 hours as I write this) I saw loads of steam rising off the dome. Probably would have been better to do that without the insulation in the way, but oh well.

Today's fire got a little out of control at one point, but as far as I can tell there's still no cracks. The load of firewood that we got delivered on Friday turned out to be pretty wet, so I was drying a couple logs at a time in the oven on the side away from the fire. The inevitable happened at one point, and the whole thing burst into flames, with flames licking up the vent. Broke up the fire a bit and let it die down, and eventually got it steady at around 500-550, with the dome clearing a bit at the top. Outside registered about 50 degrees, roughly ambient temperature (lovely weather for December in DC).

[rsandler]

Re: 36" Pompeii in DC

I still haven't put a flue on my vent--picking up a few ceramic flue tiles from the local brick yard is on my to-do list. Still, I've been surprised at how well my vent has been drawing all by itself. I'd say between half to 90% of the smoke goes up the vent, depending on how smoky it is and how hot the vent has gotten. The remainder is pulled upward by the vent and generally goes over my head instead of into my face, which is a plus.

I guess technically, if you start counting from the inflection point of the vent sides, I currently have a 12" flue which narrows from 14"x6" to 5.5"x6". Not huge, and not quite big enough, but it sure makes a difference.




I'm thinking I may only need one 12" flue tile to get enough draw here, although since they're cheap I'll probably buy 3 so that I have enough. I'm reconsidering whether I actually want to build the chimney tall enough to clear the deck, as so far the deck has not gotten very smoky. I think the thing would look better with just a short flue sticking out.

[cobblerdave]

Re: 36" Pompeii in DC

Gudday
And the good news is .....as the oven dries out and your fires get bigger ....your have hardly any smoke apart from at first lighting
Regards dave

[rsandler]

Re: 36" Pompeii in DC

A bit more progress on the oven. I did another couple of curing fires last weekend, including one that cleared the dome completely, and so called it good (plus a bonus fire last monday when I left some wet logs in a too hot oven to dry out overnight and *foosh*). I built myself a slightly decrepit door by covering some leftover board insulation with aluminum (still need to get a picture of it).

We have company coming tomorrow and I figured that would be a good time for an inaugural pizza bake, and we've also had a bunch of unpredictable rain lately, so I fired up the oven on Saturday just to "re-cure" and get any moisture out of the insulation. Saturday evening I made 4 dough balls for pizzas on Tuesday. I also decided I would try baking a big batch of bread on Sunday with the residual heat from the re-cure. Some combination of insufficient heat retention and bad oven management (letting the fire burn down to low coals before putting the door on doesn't seem conducive to long term heat retention) meant that by Sunday morning the oven was down to 400--too cold for bread.

So I fire the thing up again late Sunday morning until it cleared the dome. And there I was, at lunch time, with a pizza-hot oven and pizza dough in the fridge. I couldn't resist. Sure, my oven tools from FB hadn't yet arrived, but I figured I could fake it with a wood peel and a fireplace poker.





Homemade barbecue sauce, tomatoes and cilantro. A Texas Margherita, if you will. Room for improvement on the cooking. Fumbling around with the poker I burned one half, and then undercooked the other. Still pretty tasty. I just got my oven brush, square peel and round peel via FedEx today, so tomorrow's bake will go better!

After the coals were out of the oven, a good hour later with the door off the temperature finally dropped low enough for bread.
Came out pretty good! Need to let it sit with the door on to equalize a little more before baking though--on some loaves the bottoms burned.

Then Sunday evening, with the oven now at 450, we roasted a chicken--man, that was a tasty bird, wonderfully moist.

I'm loving this oven!

[rsandler]

Re: 36" Pompeii in DC

Also this weekend I started trying to stucco the outside of the dome. Based on discussions over on the "Design" forum, I established that it would probably work okay to smooth out the lumps in the insulation by piling in more stucco, as long as I had plenty of rebar wire and added fibers to the render. This only kind-of-sort-of worked. Or rather, it would have worked with more wire and more materials. Especially more materials. Lumping extra render into the weird low places created by the layers of blanket insulation was fine, but takes a lot of render! I only got about half of the dome covered before I ran out of sand, mostly ran out of fibers, and totally ran out of daylight :P. I covered the parts I'd rendered with plastic wrap to keep them moist, and I'll try to finish next week with lots more materials on hand.

[UtahBeehiver]

Re: 36" Pompeii in DC

Congrats on the inaugural fire. Your end product turned out much better than my first cooking experience. Have fun with your new toy....

[REE REE B]

Re: 36" Pompeii in DC

Awesome pics! looks like fun I think you are going to enjoy the oven so much and its good for the kids to get involved as well. You did a GREAT job!

Best

Maria

[waikato pizza]

Re: 36" Pompeii in DC

great project result - well done - hope mine is any where near close to this and I will be happy.

Once again, Well Done - Andy

[Tscarborough]

Re: 36" Pompeii in DC

I call that a "Guadeloupe".

[mrchipster]

Re: 36" Pompeii in DC

Came out pretty good! Need to let it sit with the door on to equalize a little more before baking though--on some loaves the bottoms burned.

Try giving the oven a damp moping about 30 minutes before the bread goes in and it will help with the oven temp equalization.

14 pound turkey going in the oven this evening outside temp 22F.
Chip

[rsandler]

Re: 36" Pompeii in DC

Over the last three weekends I put two coats of stucco on the outside of the oven. I tried to make a web of rebar wire in addition to what I used to tie down the InsWool blanket to give a base to render onto, and I was trying to get the lumps of the blanket (and especially from overlapping layers) smoothed out.

This did not work particularly well. I never had enough wire, the render would not stick to the blanket by itself, and even where there was wire I had big clumps of wet render flopping off the dome as I worked :P. Independent of the difficulty of the task, I ran out of materials halfway through the first layer and had to wrap it all up and continue the following week. With, as it turns out, a different kind of sand that gave the render a different color. What a pain!



The key lesson here is that it just doesn't work to use stucco to smooth out big hills and valleys. It's not that a 1-2 inch layer of render with reinforcing fibers won't hold together once dried. It's that a 1-2 inch layer of render will collapse under its own weight rather than stick to any surface at all. I don't think there was room for it or time for it, but I really should have gone with a small layer of vermicrete to smooth out the lumps instead.

Anyway, this weekend I put a second coat on, using white portland for the cement. Went on much easier, and came out cleaner, and with a more pleasant color too. It will do for the short term, anyway!



When done, I wrapped the whole thing in plastic wrap, then put a blanket on top (in case it freezes in the next couple days), then a tarp.

At this point, the plan is to leave the oven alone until spring (except for cooking, as the weather allows). Once it warms up again, it will be time to build the counter extension, pour concrete countertops, put some kind of finish on the stand and decorate the outside of the dome with a tile mosaic.

[Gulf]

Re: 36" Pompeii in DC

Sorry, that what you were trying to accomplish, wasn't what you ended up with. Vcrete/Pcrete is, (then render) in my opinion, the best way to true up a well insulated dome. However, pompeii's don't have to be perfectly symetrical spheres to be appealing. Most ain't.
I am all about "the build", but the cooking is what really counts . Your's is built by the plans, well insulated, and (I bet) is the best pompeii in the whole dadgum state. The food, the family, and the friends gathering around your oven is what we are all really looking forward to.

[rsandler]

Re: 36" Pompeii in DC

Got home yesterday after two weeks in California, to find that we'd had enough wind to rip the covers off my stucco layer--tarp, blankets and plastic wrap all in a heap! Had a moment of "Hey, the stucco came out looking nice...wait, I didn't leave the stucco uncovered, did I?" Ah well, I'm fairly sure it stayed on long enough to let the stuff cure. And if it doesn't, and cracks? We'll cover it all with tile in the spring.

Quick question for the forum: with two layers of stucco on (and most of it fairly thick), approximately how waterproof is this thing? I recognize that it won't fully keep rain out without some kind of acrylic or other seal, and so I ought to tarp it if major rain is expected, but how worried should I be about it getting drizzled on in its current state? It seems like it couldn't be too bad--even if moisture gets to the blanket, all that will do is decrease the insulating efficiency a bit, and it seems unlikely that water is going to get through an inch of plaster and 5 inches of blanket to reach the bricks, barring a deluge.

This weekend for some reason we're supposed to get weather in the 60's (San Diego weather followed us home?), and I'm planning pizza, bread, and pork spare-ribs during the week with the retained heat.