Another UK oven started

[Frances]

Re: Another UK oven started

In effect, you are doing the same thing that Frances did with the fireclay mortar, except you are using really really tiny firebricks.

Funny!

Mine's working fine, so that's a good omen. When do you plan to start firing it Carl?

[Xabia Jim]

Re: Another UK oven started

Continues to take shape....very nice and inspiring.....

[dmun]

Re: Another UK oven started

It's an interesting project, and I look forward to seeing what the cracking situation is going to be. In effect, you are doing the same thing that Frances did with the fireclay mortar, except you are using really really tiny firebricks.

Good luck with your dome. Dry it slowly, and keep us posted.

[Carl]

Re: Another UK oven started

And when you look at it from the back, it looks like this:



I even had some time to finish off one wall of the summerhouse, using my recycled fence boards:



Building the dome this way was good fun - very fast, and easy to do. Hopefully my idea of building the oven around the chimney will work out OK - I plan to fill the gaps with a vermiculite/fireclay mix once the dome's dried a bit. I'll scrape the sand out of the dome in the next day or so, then leave it to dry. I know I'll get some cracking with such a high clay content, but hopefully I can patch these up once it's dried out.

More pictures on the blog if anyone fancies a look. Hope you're all getting warmer weather than me...

[Carl]

Re: Another UK oven started

I used a sand dome as a mould for the clay dome - planned for 32" internal diameter, and 15" high:



I've used a 50% fireclay, 50% firebrick grog mix for the clay dome. The grog was very coarse - more like fine grit:



I built the clay dome in about 3-4h - very quick, compared to how long it would have taken me with bricks. Three quarters of the way through it looked like this:



The walls were about 3.5-4" thick all round. When finished off it looked like this:

[Carl]

Re: Another UK oven started

It's been a while since I last posted - but I've been busy! It's been cold here - below freezing most nights, and only around 2-5 degrees C during the day.

Firstly, I finished off the chimney bricks and flue (a recycled length of twin wall 6" internal stainless chimney, ?30 off ebay):



Once this was finished I could finish the roof of the summerhouse off:



After that came the oven hearth - recycled firebricks (from ebay) laid on their thin sides, on a thin layer (~1inch) of sand on top of my insulating concrete blocks:



Next I built an inner arch (the oven entry) that will become embedded in clay when I build the dome. The bricks were held together with the same 50% grog, 50% fireclay mix that I'll use for the dome. The top bricks in the arch were my fancy ones with the corners chopped off - these were all from freecycle:

[Frances]

Re: Another UK oven started

Beautiful archway - I allready liked the stand more than a little, so I'm looking forward to seeing how the dome turns out!

I'm always amazed by the range and quality of the used building materials on ebay.co.uk : of course you have a compact geography and a thousand years of built structures to demolish and re-distribute.

This comment of Dmun's fascinates me. I lie awake nights thinking of all the old buildings that must be being knocked down around here, all the beautiful old bricks I could do things with, old tiles, whatever. The difference is, in Switzerland no-one would ever think of putting them on ebay

[gjbingham]

Re: Another UK oven started

Interesting Carl. I'm watching your progress. Spring's coming!

[Les]

Re: Another UK oven started

Sometimes the easy route is the best path to take

Looking good.

Les...

[Carl]

Re: Another UK oven started

More work on the entry and chimney this weekend. The arch was soul destroying - I spent an hour making a beautifully measured mock up, cut two fibreboard supports to size, then wasted 2 hours trying to get the bricks to fit.

In the end I just dropped the support and used wooden wedges to jam everything in tight.



This was the most infuriating bit of masonry work I've ever done - mind you, I've learned from it and would do it differently next time. My bricks are all different sizes too, which doesn't help. Excuses, excuses...



The arch is about 1/2 inch away from the brick ledge behind, with an air gap in between. I want to fill this with an insulation mix to reduce the risk of the arch cracking as the chimney heats up. Making a rod for my own back I guess by making this more complicated than it needs to be. The only recycled bit this weekend was the angle iron supports - free, after 20 minutes angle grinder work on an old bed frame

[gjbingham]

Re: Another UK oven started

Awesome work. Summerhouse huh? Looks like a real house around here.
George

[Carl]

Re: Another UK oven started

Well, the timber frame is up now, covered with a corrugated roof. It took a long time to do, especially since most of it was done in driving rain.

The frame will be clad with timber eventually, but right now I've hung a halogen light in there so I can keep working on the oven masonry. I've started on the entry to the oven and the chimney. Sounds daft, but I want the chimney done before I've done the dome - the roof isn't finished yet because I've got to poke the chimney through it. Once the chimney's done, I can finish the roof, and build the rest in the dry.

Hopefully I can get the entry arch done in the next week, if our very mild weather continues - only going down to 7-8 C at night at the moment.

[sarah h]

Re: Another UK oven started

This is a very intriguing idea!
I want to build a second oven on an island this summer but can't see loading and unloading individual bricks and blocks into the car, out of the car, onto the boat and then off again - sacks of materials like this if I can find them, mixed up once on-site, might just be the solution.
I'll look forward to seeing how you get on with this - best of luck!

Sarah

[Carl]

Re: Another UK oven started

Not a lot been happening on the oven build at the moment as it's so cold outside. Instead I've nearly finished the wooden frame of the summerhouse - but haven't taken any pictures yet as I'm working right up to when it goes dark - about 1630 at the moment...

I've decided to build my oven dome out of 'mouldable firebrick' - a mix of gritty firebrick grog and fireclay. I've run a few tests on different mixes - testing to see how strong the wet mix is...



and testing how strong the bricks are after drying (and firing in the centre)...





There's much more info on my blog if you're interested. I've settled on a 50% grog, 50% fireclay mix - this has a small degree of shrinkage, and is really tough when dry. I'm hoping that this will turn out to be a sort of hybrid between a firebrick oven and an earth oven - the ease of moulding of the earth oven, with the strength and heat resistance of firebrick. As ever, I'll keep you posted with progress...

[dmun]

Re: Another UK oven started

The cladding for the summerhouse is coming from a demolished fence - more recycled products being used. Also very cheap - good old ebay!

I'm always amazed by the range and quality of the used building materials on ebay.co.uk : of course you have a compact geography and a thousand years of built structures to demolish and re-distribute.