somewhat experimental 36'' build, Fethiye, Turkey

[blackjimmy]

OK, was planning this for a while in my head (with frequent trips to the forum for research!).. I persuaded my folks to let me build it at their place in the Kaya Valley near Fethiye, Turkey.

The main challenges were lack of availability of materials, and lack Turkish-speaking ability needed to find out about availability of materials. I had a few advantages at the start though. There was a concrete pad next to some stone steps which was available to build on and accessible by standing on the steps.. not ideal maybe, but it saved me the hassle of building a base/platform. Also there were a few materials left over from the building of my parents house.

I say this oven is somewhat experimental because I couldn't get a hold of:

Fire bricks
refractory mortar
ceramic blankets
vermiculite or perlite

(That's not to say you definitely can't get these materials in Turkey, just that I couldn't get them. I'm sure you could get them imported at some expense. I asked in about 10 garden centres, building suppliers, brick yards, landscape suppliers for vermiculite or perlite, but nothing.)

So working on the principle that an unconventional oven was better than no oven at all, I used:

• terracotta tiles (2 layers of 1 inch thick tiles) for the cooking surface
• clay bricks for the dome (they really are the dodgiest, crappiest, crumbliest, misshapen, barely-fired brick imaginable!)
• pumice for the insulation (hearth and dome)

So it's nearly finished. Just finished the insulation, although it needs some more shaping. It was very tricky to get an even thickness all the way round because I was using cardboard as a retainer and pouring up against it in layers.. it collapsed on me a few times ! Working with 'pumice-crete' is like trying to build with breakfast cereal.

I've had a few small curing fires and I'm going to start ramping up the temperature from now on. So far so good.. the chimney seems to draw well and no cracks/split bricks/falling chunks of mortar yet.

By the way although I saw a few mentions of the possibility of using pumice has anyone else actually tried using it on an oven yet? What kind of efficiency do you get compared to vermiculite? I hope it's insulating enough..

[jmhepworth]

Re: somewhat experimental 36'' build, Fethiye, Turkey

My guess is that it will work great. Keep us posted.

[cynon767]

Re: somewhat experimental 36'' build, Fethiye, Turkey

Working with 'pumice-crete' is like trying to build with breakfast cereal.

don't worry- the perlicrete/vermicrete aren't much easier. I likened it to trying to make rice krispie treats with powdered milk instead of marshmallows. It's difficult to make it hold any kind of shape at all until it starts to cure. Once it did, though, it held it's shape just fine.

Did you use portland cement in your pumice mix? If so, at what ratio? I am very curious to find out how well this works; it sounds like a great experiment! Good luck, and keep us informed!

[blackjimmy]

Re: somewhat experimental 36'' build, Fethiye, Turkey

Did you use portland cement in your pumice mix? If so, at what ratio?

I used a *rough* ratio of

5 parts pumice
1 part portland cement
1 part sand

I chucked the sand in as well to try and bind it together better as the pumice particles were pretty big, but I don't think it really worked that great.. most of the sand just flowed to the bottom after pouring.

It's interesting you said that the vermicrete is tough to work with as well? I had it in my head that it was easy and you just plastered it on?! I take back all those jealous thoughts I had about vermicrete users as I was struggling with my pumice!

[blackjimmy]

Re: somewhat experimental 36'' build, Fethiye, Turkey

Well another successful curing fire today. I burned 5 or so thumb-thick sticks, which burned for 20 mins or so. I will continue to escalate the heat tomorrow and may do 2 burns. So far no complaints from either the mortar (non-refractory) or the bricks (standard clay).. which were some of my biggest worries as I know it's sub-standard to what most use. At least a dome is a self-supporting structure so if all the mortar goes to crap it shouldn't collapse!

At times of high smoke (starting and ending the fires) the chimney seems to get overloaded and smoke comes out the front.. I assume this is nothing to worry about? The chimney draws well when the fire is burning nicely, but I think my vent may be slightly too small for the oven. Maybe not.

[jmhepworth]

Re: somewhat experimental 36'' build, Fethiye, Turkey

Smoke out the front will discolor any finish materials. It's likely only to smoke on starting or if you have wet wood. Once it gets up to temperature to cook pizza, there is almost no smoke at all.

[blackjimmy]

Re: somewhat experimental 36'' build, Fethiye, Turkey

Thanks Joe, that's pretty much what I'd thought. The arch does get a bit of smoke on it in the beginning but it soon stops after the fire gets going. I'm not too worried about any discoloration anyway.

Another fire today, this time I got it going pretty hot and it burned for over 30mins. I think one more tonight and then another 2 tomorrow, and then maybe pizza the day after! Can't wait.

[blackjimmy]

Re: somewhat experimental 36'' build, Fethiye, Turkey

Well I had another (final) curing burn this morning in preparation for P-day tomorrow.. my dough is resting in the fridge as I type. The oven is performing admirably so far. I had a large fire and burned it for at least an hour.. the pumice on the top of the dome outside felt only very slightly warm to the touch! Success! I've found only a little info on using pumice on the FB forums.. is this the first documented pumice build???

After the fire had gone to embers (and I'd cooked a massive aubergine (beautifully) and a couple of potatoes) I shut the door. I just rechecked the oven and it's still hot 6 hrs later.. so the insulation seems to be doing it's job. Because of the largish size of the pumice particles, there are quite a few larger air gaps between particles. I've got a feeling some cold air/wind can penetrate down through these gaps and is decreasing the efficiency to some degree. I think once I've rendered over the pumice it should improve the efficiency even more.

I've got my first crack, but it's small and it's where I thought it may crack. When I made the chimney vent I just used scrap terracotta tiles and then mortared all over the top of it. It's the place with the largest areas of exposed mortar (bear in mind I'm just using regular mortar) and it has cracked close to where the steel tube slots in. It's possible even the heat coming out and up over the front from the opening has cracked it. When I apply the render to the outside I was already intending to patch up the chimney vent as well, so it's not such a big deal.

I'm also sure that my chimney vent is to narrow, as smoke leaks out the edges of the doorway and up over the front of the arch. I've found that wedging the door half-in narrows the air intake and gives a better suction.. this suction doesn't allow the smoke to push out through the front and forces it up the chimney.. it seems to work well and is keeping the front smoke-free.

I'm still completely in the dark about what temperatures I'm achieving. I have no thermometer. I was trying the 'counting Mississippi's' method.. but where do you hold you hand??! If I hold it at the bottom it's a lot different to if I hold it towards the top of the dome! I'm slightly worried about getting the temps wrong when I cook pizza tomorrow... I guess if in doubt just go for it with a big fire? Is it likely that I could go too hot? I also have no idea how hot the cooking surface is getting, and no idea how well my underfloor pumice insulation is working? I guess experience will tell.

Bring on P-Day!

[papavino]

Re: somewhat experimental 36'' build, Fethiye, Turkey

Well, yeah, you can get it too hot, but I wouldn't worry about it. If you put your first pizza in and it burns without cooking throughout, then it's too hot. Just let the fire die down a bit and try again. Just go for it. You are right when you say experience will tell.

[Mitchamus]

Re: somewhat experimental 36'' build, Fethiye, Turkey

great job!
I'm sure it will work out fine.

[blackjimmy]

Re: somewhat experimental 36'' build, Fethiye, Turkey

Today was Pizza-day.. and it was very successful! I fired the dome to almost scary temperatures! well probably not scary for you guys, but scary enough for me as it was the first time I've taken it so high. The dome turned white as I've read on here that it would, and the oven seemed to be almost throbbing with heat.. hard to get near it!

I did 2 pizzas.. both worked out well. I made the first one slightly too big for the peel and it got a bit misshapen but it cooked in under 2 mins. The second one was the better one although it took more like 3 mins.. I think the hearth hadn't reheated fully from the first pizza. The 'go for it' method of fire seemed to work well. Also it was my first time working with the peel and it turned out to be a lot easier than I'd thought.

I think here is a good place to say thanks for all the info and advice that I've got from the FB forums! I couldn't have done it without all of the help I've got and been given here.

I'm also pleased with the way the materials have worked in the oven. I remember reading on the Pompeii oven-plans page this advice to people who can't get hold off/afford fire bricks:

"If your choice is to build your oven with clay brick or not at all, we would strongly recommend building your oven with clay brick."

This is the attitude I took with pretty much all of my materials. Couldn't get refractory mortar so used regular, couldn't get firebricks for the floor so used terracotta, couldn't get blanket or vermiculite so used pumice. I figured that having an oven which is slightly less efficient is better that no oven at all! So far the materials seem to be working really well. I did a cost estimate and I think that in total it cost me about 80GBP or 130USD.

[ThisOldGarageNJ]

Re: somewhat experimental 36'' build, Fethiye, Turkey

I did a cost estimate and I think that in total it cost me about 80GBP or 130USD.

wow.... wish I could say that....

Congrats on sucessful completion using irregular materials... Its good others in your region will find out there are other ways to build..

Cheers
Mark