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Post by cobblerdave on Mar 16, 2015 10:57:04 GMT
G'day Phil If you going down the path of cutting both sides to get rid of those inverted Vs and cutting top and bottom to get full tight brick of course go the fireproof mortar. It sets fast and handles the sub 5 mm gaps. If your cutting the sides only the "home brew Mortar " is better as it allows you to set the angles of the outside of the bricks with a bigger gap. The large inverted V gaps are not really noticeable in the lower rows of brick they only really start about a half up the oven. So that point is where you put you biggest efforts and fancy cuts. 1/2 way up the oven is also where gravity starts to make itself known. With home brew use and a bigger outside gap an angle grinder to put some random scours on top and bottom surfaces of the brick it helps the Mortar to key much better. As the brick count for each ring of brick goes down and the time in setting each brick goes up it time to mix less and less mortar. Measure by the cup into a 20 ltd plastic drum mixing with a paint mixer paddle on an electric drill works well. As for grog which is basically crushed fire brick, I can't see myself needing something that's rated at 1200C when the most your oven should need is 600C. Use the lyocal sand and spend you money on the important things like insulation. Anyway Phil your the builder and your the man on the ground, I can advise and give my own opionions but you have to make the decisions. Regards dave
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phi1
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Post by phi1 on Mar 16, 2015 18:26:23 GMT
Really interesting weekend, wasn't allowed to go shopping so didn't get Thermalight blocks or sand and cement for the insulating base between the slab and hearth base (Mothers Day so SWMBO ruled the weekend) Too the opportunity to cut the hearth fire bricks and lay out my design. Must stress I am not a builder and defiantly not a bricklayer but having great fun with this project. The base was going to be 1m diameter but is now 900mm following Cannyfradock post below my home made former is too large, the width is 520mm (should be 450mm) and the height 260mm ( should be about 280mm) Also as can be seen the sides of my pro-former are lower than the soldier brick at the sides, should I redesign the pro-former so the arch matches the top of the brick? Finally, is the throat big enough? As I am just setting this out I can move it back a fraction, as can be seen I have excavated the base out of solid chalk, put a 100mm base down which is 1500mm x 1500mm and cemented the stones back across the front. (I still ache) Please be as critical as necessary, I would appreciate any ideas or comments at this stage. Thanks Phil
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phi1
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Post by phi1 on Mar 16, 2015 18:28:22 GMT
I forgot to add, I am going to cover the slab with insulating blocks (100mm)
Any suggestions how to finish the area around the oven once it is completed?
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Post by cobblerdave on Mar 17, 2015 10:48:15 GMT
G'day phil Sorry my main computer screen is down at the moment so I have no way to refer back to you questions except to use desktop which is a bit hard on my phone. r.search.yahoo.com/_ylt=AwrSbmIU_wdVthEAV5rpQyE5;_ylu=X3oDMTByaTNkOWxlBHNlYwNzcgRwb3MDNwRjb2xvA2dxMQR2dGlkAw--/RV=2/RE=1426616212/RO=10/RU=http%3a%2f%2fwww.wood-firedoven.co.uk%2fdownloads%2fwood-fired-cooking.pdf/RK=0/RS=2ojplw2abqUJEVNMCaNmCvOSYeE-The link I've attached is the one I used for my oven . No it's not perfect but it will help. 101 pages from memory. Enjoy First, you have been busy. Mother's Day or not. Don't try to build your oven and entrance as one. Build the dome with an opening , an oven mouth at 63 per cent of the height of the oven roof. Width will be roughly 1/2 the width of the oven. Depends on where you set it. Then build the entrance way to but to it. It's wider and higher than the oven mouth do you have a revel to fit an insulated door too. The entrance is to protect the oven door from winds and to funnel the smoke above your head. The 63 per cent oven mouth is to make the oven breath correctly. Build it bigger than the oven mouth, If you start with a solider you will find that you dome will have to have a lower dip than a half hemisphere to keep you internal hieght at 1/2 the width of your dome. You can use just an ordinary brick height to start the dome and get the 1/2 hemisphere dome. Or if you want the full soilder row, cut yourself a full size cut out of the dome shape and cut that in 1/2 down the middle and use this to set you IT for every course. It wil work. As for the set back, you'll want about 1 and 1/2 bricks set back, this is of course dependent on how far you oven mouth bisects the circle which is the base of your dome. Me I'me your visual type so I got a couple of big cardboard boxes and cut out the dome size and hieght and door. Regards dave ukwoodfiredovenforum.proboards.com/thread/1877/budget-pompeii-build-winchester Big daves oven is a great example of an oven entrance built after the dome. Again fat fingers and I-phones. Sorry
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phi1
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Post by phi1 on Mar 28, 2015 14:20:30 GMT
Another question
I have ordered a tub of fire cement for where the joints are >5mm, hopefully the inside of the oven and also a supply of sand, cement lime and fire clay
Is it ok to mix home-brew mortar with fire cement? I don't mean together but use fire cement up to 5mm and then the rest of the joint with home-brew
Thanks
Phil
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Post by cobblerdave on Mar 28, 2015 22:34:47 GMT
G'day. Phil Thad a big NO on mixing fire cement with homebrew. The lime in the homebrew set off the fire mortar nearly instantaneously. Fire mortar set fast enough as it is. Regards Dave
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Post by Dave the cobbler on Mar 29, 2015 7:26:00 GMT
G'day Phil Sorry for the blunt answer but I was heading to work. Now I was talking about ciment fondue, calcium aluminate, not air dry products that set by heat, you don't want them. I know that type as flu set. Ciment is used to make rapid setting agents for Portland cement produces like floor levelers. So it looks like it reacts with the Portland as well. One of the members used ciment fondu and grog ( crushed firebrick) as his mortar. When I find a bit of time I'll track it back and see how it worked. For my personal preference I used homebrew and found the clay content allowed you a certain amount of moving the brick about to get it right, without lossing the bond to the brick. The longer setting time means you have more time to muck about getting the brick right without the mortar being wasted. I'm a pretty poor bricklayer so these were important. Regards Dave
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Post by cobblerdave on Mar 29, 2015 11:59:07 GMT
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phi1
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Post by phi1 on Mar 29, 2015 14:27:12 GMT
Thanks Dave, Ive dropped him a pm
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phi1
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Post by phi1 on Apr 7, 2015 11:55:25 GMT
At last a weekend with no rain and a bank holiday I laid the Thrmalite blocks on the concrete stab. My first attempt at bricklaying and quite chuffed with myself. Any bricklayers out there you are my hero trying to get levels on three dimensions not easy Anyway I have now set out my firebricks on the blocks but it's not 100% flat, not too bad for a first attempt but some joints out by 1 or 2mm. I will tidy up the cuts, cutters got a mind of it's own My question is should I lay the firebricks on a bed of dry sand? If so, how deep? I was not planning on using any mortar or cement on the base of the oven based on posts on this site. Heres where I am at
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Post by leetheldc on Apr 7, 2015 12:42:26 GMT
Hi Phil, I just laid my floor bricks on sand so they could easily be replaced if needed I used the grog I had for my mortar, I used a notched tiling trowel with 10mm notches so I could tap the bricks diwn where needed so all in all the sand layer was about 10mm thick hope this helps
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Post by cobblerdave on Apr 7, 2015 12:56:12 GMT
Gday Phil Id lay it on a layer of 50/50 dry sand and powdered clay. If the thermolite block is out 1 ml or 2 id make it a 3 to 4 mm layer. If those thermolite block is like the hebel I'm used to and pretty soft, take a house brick, you know the ones with the holes. Rub it across the raised edges of the thermolite block and it should shave of the raised edges. It won't make it perfect but it will help. When laying the hearth brick, bring the brick up and touch the side of the previous brick layed. Then drop into position. If you just push them together the sand/clay builds up at the front of the brick and you'll never get them tightly together. Bricklaying a definite art. I"m the first to admit I"m "masonry impaired" Even though I pulled off building a dome out of square bricks my bricklaying still sucks. And that's why I always like the "homebrew Mortar" its pretty forgiving and easy to use Regards Dave
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phi1
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Post by phi1 on Apr 7, 2015 17:39:53 GMT
Hi Phil, I just laid my floor bricks on sand so they could easily be replaced if needed I used the grog I had for my mortar, I used a notched tiling trowel with 10mm notches so I could tap the bricks diwn where needed so all in all the sand layer was about 10mm thick hope this helps Thank you both, exactly the advice I am looking for. I understand dropping the bricks so as not to cause a bow wave of sand. I have a rubber mallet to tap down the bricks, I was thinking about using an old vibrating sander to vibrate the bricks home, any thoughts. Lee, you said sand then grog, is this the same advice as Dave but grog instead of clay? Is building sand ok? I have bought some for me Home-brew Mortar ? Its soaking wet, should it be dry? Weather looks good this week so I am hoping I can crack on. Dave, thats two of us Masonry Impaired, cack handed with the trowl, drop mortar everywhere, took me as long to clear up as lay the base . To be honest I am really enjoying it, really satisfying at the end of the day
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Post by leetheldc on Apr 7, 2015 20:25:45 GMT
Hi Phil I was referring my grog to sand I just used the grog as that's what I had to hand. As you have the home brew ingredients like dave said dry 50/ 50 with your sand and clay will be great easier to work with dry. As the weather is ok at the moment spread some sand out to dry in the sun enough to lay the hearth bricks.As for the sander method you must have watched some block paving crew lay an area at some time in your life to say something like that! Just like a mini whacker plate.but a simple rubber harmer will be just fine for what you need
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