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Post by cannyfradock on Apr 8, 2015 18:58:32 GMT
Hi Phil
Great to catch up on your build thread. Brilliant advice from the members on each stage. I also use the same technique for laying the hearth bricks as other members. Lay the mortar bed with a notched trowel and gently tap home with a rubber mallet. Always dry butt the bricks next to each other. Fire-bricks look perfectly square....they're not! and sometimes you can't avoid the odd few from slightly sticking out by 1 or 2 mm's from your flat hearth. If I come across this I simply use a 4" angle grinder to gently grind down any edges that might catch on your pizza peel.
I normally lay my hearth bricks on homebrew. When I order bricks for a new oven build I always get a bag or 2 of dry fire-clay. This mixed with Hydr. lime sand and cement (ratio of 6:1:1:1)creates the homebrew.. I use this for my dome and laying the hearth. I have also used sand cement and lime (ratio 5 or 6:1:1). I have also used (powdered) flexible floor tile adhesive.....as far as I know ...they still all work well.
Terry
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Post by miniadventure on Apr 10, 2015 17:03:11 GMT
Hi, Just so im clear i presume you mean builders sand? normal cement used for brick laying ? not too sure what portland cement is... and hydrated lime and powdered fire clay, with a little water?
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phi1
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Post by phi1 on Apr 10, 2015 18:33:24 GMT
Had a fantastic day, oven base firebricks laid and levelled, first course of bricks laid as soldiers. Never going to make any money as a bricklayer, it took me all day Question I have now is do I fix my IT to the fire bricks or do I raise the base of the IT to the hight of the soldiers? I am guessing I work from the firebrick level or it will make my dome 150mm higher than planned and mess up my calculations for the opening (63% of the hight)
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Post by oblertone on Apr 10, 2015 21:56:38 GMT
Excellent progress, now the fun starts ! As an aside, is the base board in sections because it needs to be to get it out off the dome once you've built it.
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phi1
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Post by phi1 on Apr 11, 2015 8:23:43 GMT
Excellent progress, now the fun starts ! As an aside, is the base board in sections because it needs to be to get it out off the dome once you've built it. The base board you can see is MDF to protect the base, I have a second base board made from thin ply which is cut in half, if all else fails I can burn the ply inside I'm not sure how to fix the IT to the base without damaging a fire brick Raining again today so stalled again
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Post by chas on Apr 11, 2015 9:49:36 GMT
I'm not sure how to fix the IT to the base without damaging a fire brick Hi Phil - IT... are we talking about the bit of stick (trammel) used to swing round and keep the diameter constant as well as giving the angle for the dome? For it to work, it describes a constant arc and so produces (with your help) a perfect hemisphere. So yes, it will raise the dome above the floor by the net height of your 'soldiers', and yes, that may well cause you to re design the doorheight to keep to the 63%. Your internal roof will be net height of the soldiers inside + radius of circle. You don't fix the trammel, it pivots around a fixed point. You can put anything heavy in the centre of the floor, raised to the height of the soldier course with a screw or something set as a pivot-point at dead centre to work from. That heavy ie stable base could be bricks laid in a weak mortar easily broken out afterwards or a timber frame - anything you can get out of the doorway afterwards. You could mortar the bricks down to the protective ply or mdf. If raising the dome height and its ramifications aren't acceptable/possible and the trammel can't do it's conventional job, then you could work the trammel off a screw set in the centre of your protective board and accept a less-than-exact hemisphere or, maybe use a mound of sand instead and accept the dome won't be a hemisphere: lots of ovens aren't. Big, commercial ovens aren't. Enjoy this next bit, the dome bit - it's the magical bit. Chas
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Post by cobblerdave on Apr 11, 2015 22:03:20 GMT
G'day phil Your oven has a solider course so to have that 63 per cent height to width your dome has a flattened arch. The IT will have to be adjusted at each course of brick. To achieve this one way is to cut yourself a half shape of the inside profile of you oven. Prop this up and set you IT length and angle for each row. You can just even use the profile for the lower levels. Cut the base fitting ( to conect the IT to) into 1/3 rds as the oven mouth usually ends up under 1/2 the width. Screw them together with a few battens covering the screw heads with tape so you will not fill them with mortar. Hope this helps in some way Regards dave
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Post by bigdavenorcott on Apr 12, 2015 7:06:55 GMT
Phil - if you need any Fireclay I've a couple of full 25kg bags you'd be welcome to, just north of winchester. A dozen storage heater bricks and a few left over firebricks too
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Post by bigdavenorcott on Apr 12, 2015 7:08:27 GMT
Lol - just seen how old the thread is
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phi1
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Post by phi1 on Apr 12, 2015 8:35:00 GMT
Phil - if you need any Fireclay I've a couple of full 25kg bags you'd be welcome to, just north of winchester. A dozen storage heater bricks and a few left over firebricks too Hi Dave, will probably take you up on your offer, my initial order was from Kilnlinings but I have probably under ordered, I am really surprised how much sand and cement I am using. I do get Southampton way in the Summer as my Scuba Dive club regularly dive at Portland Great idea to post surplus bits on the forum I shall do the same (if I ever finish this project) Unfortunately I have to go into hospital on 15th for an operation on my shoulder so I think the project will come to a halt for a few weeks. Re your other post, haven't got a clue why I started this in December, just a mad moment
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Post by bigdavenorcott on Apr 12, 2015 8:45:52 GMT
Doh - sorry my mistake, saw 'Apr 11' and thought that was the year not the day =D A few months is nothing - there's ovens on here that've taken a year or two to finish
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Post by bigdavenorcott on Apr 12, 2015 8:47:03 GMT
You dive at Portland - don't know a Richard Payne do you?
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Post by bigdavenorcott on Apr 12, 2015 8:49:15 GMT
Oh yes - also got tons of second hand small quarry tiles if you want any for surround etc. No rush, I'll hang on to fireclay etc till you're up and about
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phi1
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Post by phi1 on Jun 6, 2015 15:19:35 GMT
Hi Guys, got the ok to continue with the oven as part of the physio treatment I have completed the back wall to hold the chalk back and three courses of brickwork (first course soldiers) Built the arch in the dome, taken out the former and it's still standing. Next question I can now construct the inner arch of the tunnel. Di I cement the outer arch to the dome arch or does it have to be a separate construction to allow for expansion? If I have to leave a gap, should it be filled with fire rope re can I just leave say a 100mm gap. I would like to start on the outer tunnel and chimney while I am doing the next courses as I have to let each brick "stick" individually as I have to defy gravity and use the IT . I now know my geometry knowledge is crap, I now also have the greatest admiration for bricklayers. Thank god the dome will have to be covered, it looks like a bricklayer on drugs constructed it so far. I will take some photos this evening and post them Phil
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phi1
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Post by phi1 on Jun 6, 2015 18:18:19 GMT
Photos as promised Stone wall at the back to retain chalk (South Downs). I brought the damp proof membrane up the sides of the slab and Thermalite blocks and will trap them with tiles to prevent damp from the earth seeping in. Interior brickwork and pointing. looks ok to me but I'm not a professional Indispensable tool. Still not confident at defying gravity as the dome proceeds ? Inner Arch with former in place. Don't think I would be accepted as a freemason with the construction of the arch Outer Arch former in place Finally a side view, hope to surround the oven with a rockery to try to blend it into the garden. I will use the smaller block paving bricks for the tunnel so that I can put tiles on top No work tomorrow, family day with the kids, weather looks good next week so hope to make some progress. Really appreciate any comments including tips or critism so I can get it right now rather than have to go back and fix it. Phil
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