mozo
valid member
Posts: 36
|
Post by mozo on Jul 28, 2014 15:55:01 GMT
Hi All,
After having enough of reading about everyone's fantastic builds and watching all available youtube videos, I couldn't take it any longer and I decided I might jump into the deep end.
Having not a single slither of building experience (i didnt know the difference between mortar, cement and concrete), I decided to take it very slow and build a 90cm WFO.
Obviously all the advice and tips, no matter how basic would be incredibly welcome.
Mozo
|
|
mozo
valid member
Posts: 36
|
Post by mozo on Jul 28, 2014 16:12:52 GMT
I was pretty proud of my brick work. It wasn't the best, but it was my first attempt so I was quite chuffed and hope it can support the oven. Next was to cut the plywood form ready for the concrete pour. As I wasn't using any hardibacker, I needed to make sure it was in two pieces for easy removal later on. As you can see it needed to be in a weird shape due to me using the old bbq column in the corner (i regretted this because it meant the whole support wasnt connect and therefore slightly askew) For the concrete slab, I made it 10cm deep, there was a rebar mesh placed which was propped up with a few pieces of broken brick, I think I needed a total of 11 ballast and 3 and a half bags of cement - (this nearly destroyed my ford focus!!) I propped my frame up using old pieces of wood that were lying around, and filled any gaps with small pieces of broken bricks and rock.
|
|
mozo
valid member
Posts: 36
|
Post by mozo on Jul 28, 2014 16:16:57 GMT
This is after I poured the concrete. cheeky photo bomb of my fig bush, hope the oven is ready when I harvest them!
|
|
|
Post by leetheldc on Jul 28, 2014 17:06:30 GMT
Hi mozo looks like your off too a good start. What are going to build the oven out of? Fig tree ! I love these I was lucky enough to work at a guys place for a year with a 10 year old monster fig tree he hated them so we gorged on them all summer as they ripened on the tree each day a million times better and bigger than the no tasting little ones from veg shop or supermarket
|
|
mozo
valid member
Posts: 36
|
Post by mozo on Jul 29, 2014 0:18:32 GMT
Hi Lee,
I have had the tree since last year this is the first year it has grown fruit, and already I can see a lot growing, I cant wait to enjoy them in the late summer!!
I will be making a brick WFO. I spoke to liam to discuss the purchase and I have come up with the following materials to build the oven (35.5')
185 x (230 X 114 X 76mm) fire bricks 2 x 40mm Calcium silicate boards 2 x 7.32m 50mm (96kg) LBT HT blanket 4 x lightweight insulating castable
I was also told to get some ready mixed fire cement, but I read that if the gap between the bricks is larger than 5mm, the mortar wont set.I don't have the confidence to say my brick work will be anything as accurate as it seems like it has to be. Instead I might get some fireclay to make some homebrew, does anyone have any idea of the amount of fireclay needed, also as I don't want to go over the 1000kg limit, I may need to buy the fireclay from elsewhere, any idea on where I can get some cheap?
do you guys think the materials are appropriate or would you change anything?
|
|
|
Post by cobblerdave on Jul 29, 2014 11:07:40 GMT
Gday The high thermal qualities of fireclay are not reached in a WFO. But the clay content does provide a workable mortar one that sticks to the brick and allows you to squish the mortar down. Powdered clay can be substituted or use brickies sand or builder sand witch has a clay content. The sand component is the a stuff that all other sticks too. The Portland cement is the first glue to set and keep you structure together. It tends to break down over 300C and that's where the lime content starts to harden and replaces the final "glue" that's keeps the sand together . Together it all works and provide us mug oven makers with a cheap and easy mix to work with Regards dave
|
|
|
Post by lollabrigida on Jul 30, 2014 17:10:38 GMT
Hi Mozo, another NW london WFO project about to launch in the next day or 2. I was wondering what width those concrete blocks are as i want to build my base from reclaimed London stock, but not sure if they with be solid & strong enough. Any thoughts? Also, is the 90cm the inside or outside of the oven? My slab is going to be 1 x 1.2m and am guessing the materials for the oven are going to be very similar. Thanks Ben
|
|
rokdok
WFO Team Player
Posts: 130
|
Post by rokdok on Jul 30, 2014 21:27:05 GMT
Mozo, You'll have a few firebricks left over with that quantity which is no bad thing, that is if you are going to taper them-if you are going to simply bolster the firebricks in half then you won't need so many. Blanket is about right - you can't have too much insulation, and one roll of 50 mm will not be enough. I had some left over when I got a roll each of the 50 mm and 25 mm.Have you considered using thermalite blocks for insulating the base ? A lot of people on here use Cellcon or Hanson Turbo blocks - if you use the forum discount from Jewsons they are not expensive. I don't know what the insulating cartable is or what you use it for though . Cheers RD
|
|
mozo
valid member
Posts: 36
|
Post by mozo on Jul 31, 2014 19:51:42 GMT
Ben, Goodluck with the build, it would be nice to see how you get on, and also pretty cool knowing there is some near by that I could buy and sell extra kit from! I was hoping to do a 90cm internal diameter oven, and for the concrete slab I made it 120w x 150l because this is all the space I could work with. I think Ideally it should be bigger but I dont mind the completed dome hanging over the sides a bit. This gent on youtube had a a design plan for a 84cm oven and I was hoping to use it as a rough template for mine www.youtube.com/watch?v=cb3ZC74yf9A RD, thanks for the heads up, I was worried I may have ordered too much, I am also worried I got too much insulation, I think one 25mm and one 50mm would have been better for saving space as my slab is only 120cm wide. I did consider thermalite blocks and I was VERY tempted, being a student I wanted to budget heavily. But I was told by Liam (from kilnlinings) that calcium silicate not only insulates the underlying concrete from the heat but also reflects it back into the oven unlike the thermalite. It was more expensive, but I didn't want to regret it later and not have the ability to change it. MZ
|
|
mozo
valid member
Posts: 36
|
Post by mozo on Aug 1, 2014 20:39:15 GMT
3 days since the order and its all here, all 956Kg of it! Cant wait to get started tomorrow.
|
|
mozo
valid member
Posts: 36
|
Post by mozo on Aug 1, 2014 21:11:49 GMT
Guys I was hoping for some help. I have a slab that is 120cm wide and 150cm long. I was hoping to build my 90cm on it. I thought it was large enough and it was all the space I had, but now I realise that some of the blanket layer and a lot of the castable layer around the sides will stick out. Can I get away with some of the outer insulating layers sticking out the sides or should I try and reduce the internal oven diameter significantly in order to get the sides to fit into the 120cm??
thanks
mz
|
|
|
Post by leetheldc on Aug 2, 2014 11:10:35 GMT
Hi mozo looking at your block stand you could put a brick skin around it to give you the extra width needed more work but gives you the size you want and also gives a nice finish to the base so wouldn't need to render it
|
|
mozo
valid member
Posts: 36
|
Post by mozo on Aug 2, 2014 12:43:50 GMT
Hi mozo looking at your block stand you could put a brick skin around it to give you the extra width needed more work but gives you the size you want and also gives a nice finish to the base so wouldn't need to render it Sorry by "brick skin" do you mean adding a wall to the side of my block? that sounds like a good idea. A friend suggested I build a little side compartment on the side which could also be used for storage, this would be a wooden frame, since it is only required to support some of the insulating layers would that work?
|
|
|
Post by leetheldc on Aug 2, 2014 17:22:05 GMT
Hi mozo yes a wall around is what I ment I think if you where to use the wood frame there might be an issue with damp going up through the wood into the insulation maybe if you topped the wood with thin lengths of stainless steel this would create a Barrera between the 2. But I think you need a little wisdom from cobbler dave on this one he would have a better idea I think . There should be a way on this forum to bring tag him in this thread for his attention il do my best to ask him
|
|
|
Post by cobblerdave on Aug 2, 2014 22:37:50 GMT
G'day www.fornobravo.com/forum/f51/new-36inch-castable-build-brisbane-19976.htmlThe link here is on oven that has its insulation overhanging its base. Its doable if you like the look. You could caste another slab on the top overhanging your base. Its strong as long as you use steel in the structure. It's called counterlevering . I'd be mindfull of how high it makes your hearth. Best practice has it about you elbow high to be comfortable to operate your oven. Building a brick skin, a wall around your base sounds great idea it gains you another 230 mm, if you have enough space left on your ground slab, that would be my choice. It would give you some brick practice as well. Any thing you do I would include a waterproof membrane under you insulation layer to ensure you have at least one unbroken water proof layer between the ground and you insulation. Hope something here might help Remember to enjoy the journey on you way to a WFO Regards dave
|
|