UK 34" rounded square Oven Progress.

[dmun]

Re: UK 34" rounded square Oven Progress.

Don't go crazy beefing up your render just quite yet: One inch of blanket is about half what's recommended. You may find you may need a few inches of vermiculite concrete before your final finish.

Good looking job, by the way.

[hulkiebear]

Re: UK 34" rounded square Oven Progress.

With the cracks in the FB dome sorted, I set about covering the dome with 2 layers of 1" ceramic blanket! When the guy in the builders merchants said, "careful with this stuff, it's nasty!" he was not wrong! I felt like I had been dragged through a field of stinging nettles, topless! Ouch!

Next, I covered it with chicken wire, then a scratch coat of render(I added some quick drying cement to the mix for the lower parts of the side, to avoid it slumping off!)

Hopefully tomorrow, I will do a much thicker top coat, as it sounds very thin and easter eggish!

Then early next week I have a 4 foot vitreous coated 8" flu to put on top, then job done!

[hulkiebear]

Re: UK 34" rounded square Oven Progress.

More good progress over the last couple of days, the brick chimney fronting is almost complete, and some of the terracotta quarry tile are down, and it is all looking good!

I did end up putting some steel reinforcing angle iron that runs right down into the concrete slb, this will definetly stop ay outward force of the entrance arch!

Ceramic blanket has been ordered and hopefully a stainless steel twin wall flue, will be won on ebay on the weekend.

then it is just a bit of rendering and painting!

[hulkiebear]

Re: UK 34" rounded square Oven Progress.

Thankyou dmun,

I think if I had been working to the limits of the materials, then my design may not have worked, but the screed(as the morter is called) really worked well, and bonded the bricks together to make them very solid.

Yes, the gaps have already been filled, I was running low of screed, so added the dust and crushed up scrapes of fire brick(I'm glad they had some use). I still have 2 small bags left over aswell.

Next up is the insulation, hope to use 25mm ceramic blanket, and I guess I will need to use the dreaded vermiculite concrete ontop of that!

Can't wait to put a fire in it, but I am just about holding myself back!!!

[dmun]

Re: UK 34" rounded square Oven Progress.

I must say, that despite my initial skepticism, that's a good looking dome. I'm still concerned about the full radial running seams up and down the dome, but it really looks good. Are you planning to fill the gaps on the outside?

Congratulations.

[hulkiebear]

Re: UK 34" rounded square Oven Progress.

a few photos, sorry all, this thing stands up proper solid!

[hulkiebear]

Re: UK 34" rounded square Oven Progress.

The dome and enterance is finished!!! Yippee!!!!

I am really pleased with it! It is really tough and solid! I have also finished the firebrick side of the chimney/entrance area, and hope to get some red clay bricks to clad and build the chimney, then on top I plan on a 5 foot stainless steel 6" dual lined chimney(which will be removable when not in use).

This project seems to have been going on forever, but now there is definetely light at the end f the tunnel!

I will post some pictures as soon as I can!

HB

[hulkiebear]

Re: UK 34" rounded square Oven Progress.

Had a couple of productive days, but this still seems to be going on forever!

The dome is about 70% finished, the back half as good as done! Just a corner key stone to go! I am quite pleased with the finish too!

I also did the firebrick part of the front arch enterance that ties in to the dome. At the moment it is strong enough to support itself, but it will also have to support the dome and chimney, so I am going to resin a rebar into the concrete slab, vertically either side of the arch, then fix a piece of angle iron between the two, this will stop any outward force and help support the chimney.

I need to decide on the dome finish, I am worried a little about using Vermiculaite concrete, as I just can't see that it will support itself whilst going off. I think I will need to experiment with this a little.

[hulkiebear]

Re: UK 34" rounded square Oven Progress.

A few photos of the progress over the weekend.

Centre and rear arch up, very strong!!!
started to fill in the quarters(phew lots of cutting an fine tuning cutting!)
The enterance is taking shape and I know where I am going with it, and feel confident it will work.

A couple of issue's I am thinking about are, The size of the flue(maybe 8" diameter) and the insulation over the dome, originally I was going to form a house around it and just pour in vermiculite, but I (and importantly the missus) are really starting to enjoy and appriciate the dome shape and want it on veiw, so now, can I just use vermiculite cement(like with the base and a render over the top to water proof it? I really don't want to use blanket insulation or make it to large?

Thoughts?

cheers
Lee.

[hulkiebear]

Re: UK 34" rounded square Oven Progress.

Thankyou dmun, for all your input! I really appricciate it!

I checked out the link, interesting stuff! I think I mentioned in a previous thread about a concrete sleeper at either end of the arch, the suggestion of bracing at the bottom of the arch in a C shape was kinda what I meant. but I was just going to brace the centre arch at either end, also the rear arch. The reason that I was only going to do it at the bottom of the centre arch was that I figured, if that is solid, the 4 quarters will just lean in on them, also, I was a bit concerned about heat bleeding out through the support, if only a little!

I have added a couple of blue blobs on a picture to help show what I mean.

The bracing at either end, will have a couple of spreader bolts down into the slab, to act as ties.

what do you think?

[dmun]

Re: UK 34" rounded square Oven Progress.

but for now, the thing is solid enough.

I'm glad to hear this. The bracing ring you should be thinking about is around the bottom, not around the top. All the forces trying to bring down your dome have to work outward, before there's any downward movement. I would urge you to consider a "C" shaped ring around your dome, tied to your support slab. Did you look at the page I linked? Look at the illustration under example one of "STABILITY PRINCIPLE". It almost exactly describes your dome shape, and if I were you, I'd try to buttress those outward forces.

Remember that a dome that heats and cools is changing shape and size with every cycle. It's not a fixed shape, it's a dynamic system.

[hulkiebear]

Re: UK 34" rounded square Oven Progress.

It does appear that I do enjoy a challenge!

I am still thinking about the stability of the arch, for now, it seems very strong, but that could change, but Idon't think by much. I think that the weak spot will be the middle of the arch on either side, it is impossible for the key stone to fall, unless the arches either side fail some how. So, I am toying with the idea of a rebar and concrete belt over the top about 3" by 3", or maybe a pillar behind each side, but for now, the thing is solid enough.

Today, hopefully the enterance will get designed!

[dmun]

Re: UK 34" rounded square Oven Progress.

I'm watching this come together with interest. You have designed the anti-catenary arch and have at least six running seams from the top of the dome to the bottom. I think the success of the whole enterprise depends upon how you build your entry arch, and tie it into the dome, as it will bear a greater than usual proportion of the weight of the dome.

So, let's see... Strange geometry, unknown mortar... I really wish you the best, but i'm sceptical at this point.

[brickie in oz]

Re: UK 34" rounded square Oven Progress.

Never seen an arch done like that before?

Once it heats up and expands the top will drop out, maybe not the key brick, but those holding it in will......then the key brick.....

[hulkiebear]

Re: UK 34" rounded square Oven Progress.

Progress report, things have been a little slow on the buildig front over the last couple of weeks, I am training for an Iron Man at the end of June, so need to concentrate on that quite alot. Anyway, had a good couple of days, I built the arch accross the centre and to the rear and cut the blocks for the bottom course.

My main concern was the arch not holding up, but after building the arch upto the key stone then the next day putting the 3 centre bricks in, it held up just fine. then after building the rear arch and that held too, I am feeling much more confident and euthisiatic about the project.

Due to the morter(or screed) having larger particules in it(about 4-5 mill at times), I was unable to create neat morter joints, so opted for joints with no morter and bricks jointed directly to each other, this does mean, all my cut bricks will need to be spot on, but this just means taking a little bit longer. I fill the rear of the joints with the screed, but I am trying to leave 20-30 mill so once it is built, I can point the whole outer oven to make it air tight.

here are a few pic's, should get another day in this weekend to hopefully build the enterance.