Help!!!

[kurt]

I'm in the process of building the 36" Pompeii oven. I've got the dome built along with the doorway and chimney. I've fired the oven according to the directions. Unfortunatley, I started following the forum a tad bit late. The reason I say this is I wasn't watching the heigth of my oven as closely as I should have when building it. My dome heighth is 23" and my doorway heighth is 12". After rewading on the forum I see that I should have been closer to 18" dome heighth for a 12" doorway. I fired the oven up and cooked pizza a couple weeks ago. It took much longer than I think it should have. I was using wood that was quite wet. Weather permitting I'm going to try it again this weekend with good wood. I guess my question is if I have a oven that will work with the dimensions I've stated here? I haven't insulated the dome or finished off the outside of the oven yet. If I have made a critical mistake here I'd rather tear the dome apart now and start over than finish the oven and be dissapointed for years to come. Any and all suggestions would be appreciated. Thanks!

[papavino]

Re: Help!!!

Kurt,

How long did it take you to get up to pizza temps? I've recently completed my 36" pompeii and have cooked a few times with it, but it has been taking over an hour to get to pizza temps with a raging inferno inside. That time is supposed to lessen the more your oven is seasoned, and once you get insulation on top, it will hold the temp much easier. I think the issue you'll run into most with a high dome is the top of your pizzas not browning as much as a lower dome. You can just lift the pizza up towards the dome for the last few seconds as it cooks to brown your cheese. No need to tear it down, IMO. At least yet... Get some dry wood.

[dougrappe]

Re: Help!!!

Kurt, too soon to panic! I think we need a name for what you're going through, maybe "builders remorse"? I've been there myself, just a few months ago in fact.

There are lots of variables and it sounds like you are on track to eliminate some of them. First, wet wood, so much energy used up just by boiling off the water, not much left to heat up your oven. So definitely get some dry firewood and try again. Second, no insulation yet, so you're losing heat and will have a hard time getting up to temperature and staying there.

I don't think you're door height to dome height ratio is going to end up being a problem. I think the real problem is if your door opening is too tall, allowing all of the heat to bleed off through the top of the opening.

If you're using insulation blanket, I would go ahead and wrap it on the oven and try again. Heat-up times can vary greatly from what I've read, depending on how dry your wood is and how big you build your fires. I've had my 36" oven up to pizza temperature in as little as 45 minutes or as much as twice as long.

Good luck, I'm sure other more experienced builders will weigh in as well.

Doug

[kurt]

Re: Help!!!

Thanks for the help. I'm definetely going through "builders remorse" right now. I'm feeling much better though! I'll get some dry wood, get the dome insulated and try it again this weekend. I can't wait!!!

[dmun]

Re: Help!!!

Your oven is taller than standard, but be of good cheer: it sounds like you have approximated the true catenary shape that's the most strong form. As for the heating issue, your oven is probably still damp, along with your wood, and will continue to improve with the first half dozen firings or so.

Don't hesitate to insulate the exterior and continue. The worst case scenario with a too-tall oven is that you may have to lift your pizza (sky it) to get the last bit of top browning.

The only reason I'd start over at this point is if you didn't insulate under the floor.

[james]

Re: Help!!!

Don't forget that new ovens take many fires to fully cure and if there is any moisture left in the bricks, mortar or insulation, that will really slow down how quickly your oven heats up. I think you are going to be in great shape!

There is one plus side to the higher dome -- your oven should be efficient with wood, as there is an "air cushion" in the dome above the oven opening which will hold heat. I don't think you will have any problems making pizza.
James

[backinoz]

Re: Help!!!

The time that your oven takes to heat up is about thermal balance.
The heat in from the fire is absorbed by the bricks. Obviosly wet wood will take longer to put heat in than other types. Heat is lost thru the flue and insulation. This is often the biggest factor in the heat balance. The difference between the thermal mass your 23" dome and an 18" dome will be negligable. you can probably count the number of additional bricks you have used on two hands. The secret is to manage the heat losses so get that oven dry and put that insulation on.

[nissanneill]

Re: Help!!!

This creates a n interesting discussion!
Wet wood or green wood?
I often used to burn 'wet wood' in my slow combustion heater because I would run out of dry wood or I didn't want to get wet getting any dry wood that I might find.
Wood that is wet is usually only wet on the surface and will dry off very quickly in a hot heater or oven environment, but green wood is another matter!
I burn green eucalyptus wood without problems PROVIDING that there is a lot of residual heat and it will burn fiercely as there are a lot of flammable oils in it.
I have mentioned this before on this forum, but I was introduced to burning freshly cut, white dripping sap from feral walnut trees, cut and burnt within minutes. Within 5 minutes, you could not get to within 20 feet of a roaring, hot as hell fire with absolutely no smoke, a true fierce fire, so some green wood is fine, but others not!

Neill

[Lars]

Re: Help!!!

NissanNeill,
Very interesting. I had the same problems in the curing stages of my oven, by the way, and just last night I started our pizza party just after the rain broke. It's always hard to get up to temperature when there is so much moisture around ( EVEN IF YOU HAVE DRY WOOD)

And, the black locust wood I had was dry, but green. The hissing sizzle really let's you know the fire is working hard to dry out the green wood.

Over the past couple of months, I have build a couple of more storage areas and a couple of lean-to style metal roofs to keep in the forest where I am getting my wood. Dry wood is essential, and the more you split it, the more energy you can release from the same log simultaneously. Eventually I'll get it.

HELP--- where are you in Iowa? ( Eastern, Nebraska, here)

Lars.

[kurt]

Re: Help!!!

Thanks for all your help. I'm feeling much better at this point. I made pizza Saturday and the oven worked much better. I used dry wood and had a really hot fire. I put the insulation wrap on temporarily and it made a huge difference heating the oven up. I realize now that I really need to finish the dome so I can finish sealing it up to keep it dry and insulated. We've been having a lot of rain lately. I can't wait to get the dome finished so i can use the oven.
By the way, I'm from north central Iowa...about 20 miles from Minn. border.
Kurt

[nissanneill]

Re: Help!!!

Kurt,
my oven was rather water logged a couple of months ago (as the rain falls from the outdoor kitchen roof directly onto it and also down the flue void) and although it got to 500˚C it took considerably longer and a lot of extra wood.
You will also find that some woods are better for the oven than others, a little trial and error. There are other threads with such details here within the forum.
I really do need to do a little more excavation, put in the agricultural drain and a small retaining wall and extend the roof for extra protection. On the 'next to do' list.

Cheers.

neill

[Archena]

Re: Help!!!

...

Over the past couple of months, I have build a couple of more storage areas and a couple of lean-to style metal roofs to keep in the forest where I am getting my wood. ...
Lars.

What angle did you use on your lean to's? I've got to build a couple and haven't been able to decide how sharp the angle should be.