Pompeii oven in Switzerland: pics

[Frances]

Re: Pompeii oven in Switzerland: pics

Fourth course and still going strong. Keep catching myself humming the songs "I'm still standing" or "solid as a rock" while building. The last picture shows the reason I'm keeping cuts at a minimum.

My neighbour said she thought the cracks are nothing to worry about as they aren't structural. And she's an architect so she should know . I'm still trying to get the guy who sold me the mortar to tell me what exactly is in it... But hey, it's good to work with and seems to be holding up ok.

Can anyone point me in the direction of some pics of an oven doorway built with angle irons (specificaly how to attach the irons)? All I can find are beautiful arches, and the photos in the ovenplans. The irons are horizontal but the bricks are angled, how does that work?

[wlively]

Re: Pompeii oven in Switzerland: pics

I would say your mortar supplier would be the person to ask, may want to show him a picture. My comments were based on home mix, HeatStop or other "wet" mortar. If you are using a "wet" mortar, one that requires mixing water or water based than soaking the bricks should not be problem.

If you are using a pre-mixed mortar straight out of a tub that air drys also known as "air set" then you are correct and definitely don't want water anywhere near at any time.

Three quarters of my dome is 4.5 inch thick "half-bricks", with the last 1/4 1/3 bricks. I think it is a good insurance policy to layer at least a 1 cm coating of cladding to help seal the dome. I don't think that is enough to make any significant difference to the thermal mass.

Good Luck.

[Frances]

Re: Pompeii oven in Switzerland: pics

Thanks Dave. Yep, its so cool to be working on the dome!

About the cracks: the guy who sold me the mortar said not to wet the bricks too much, as the mortar needs them to absorb some water in order to dry properly. Its a heat-set mortar without cement, so as far as I can work out it doesn't need to cure or stay damp. The advantage, he said, is that it is more flexible in high heat, which means, and you're going to laugh when I tell you this, it won't crack...

The bricks seem pretty stable, I keep on catching myself leaning on them to reach further along, and they feel solid enough.

Actually I was thinking I wouldn't cover the dome, as my bricks are slightly bigger than the US ones anyway (4.9 inches a side on the half bricks) - but if its a structural issue of course I will. The problem is, if I hose down the dome before firing it, the mortar will turn back to mud. Won't it?

Any more advice is welcome :-)
Frances

[wlively]

Re: Pompeii oven in Switzerland: pics

Frances

By the looks of the cracks I have to ask, did you make sure and soak your bricks before you started mortaring? The bricks wick water just like a sponge and if the bricks are dry it sucks the water out of the mortar and the mortar tends to pull away from the brick, like your photo suggests. I filled a tub with water and placed my bricks in as they were cut to soak for 10 minutes or so while I was working.

I am no expert, but if the bricks are stable and secure enough not to move, then you can probably fix the cracks by giving the dome a good coat , say 1-2 cm , of cladding. But remember to hose down the dome first.

[asudavew]

Re: Pompeii oven in Switzerland: pics

Looks good to me!

I bet it's feeling really nice laying bricks!

I'm not sure about the cracks. .... I would imagine you could just fill them with mortar. The seasoned builders around here will know more, and I bet they will let you know soon.

Good work!

[Frances]

So far so good. It may not be not perfect, no beautifully tapered bricks or anything, but its mine!

And - sorry, but I have to ask - is the cracking in the range of the acceptable?