|
Post by veauifru on Apr 25, 2012 14:13:38 GMT
By the way... What insulation have you used between the arch at the back and the wall or do they touch the wall?
|
|
|
Post by jonnycj on Apr 25, 2012 16:22:03 GMT
Insulation is cal sil (calcium silicate board) with a cushion of fire blanket stuff round the perimeter. Good progress today, got the flu in, whole of the outside skimmed in the remaining cement/mortar, and then 3 layers of the fire blanket. This was then covered with the ubiquitous tin foil and finally chicken wire. We're now at the render stage, so more piccies tomorrow. The render comes in bags and is mixed to a porridgey type consistency with water. No need for cement mixers or getting quantities right, just add water until it's the correct consistency and apply ! Doing two coats of render, the first with waterproofing agent and the second au natural. The render has thermal insulation properties and will probably be a couple of inches thick by the time Brian finishes. It seems to have vermiculite type granules in. I have to say, going for the easy option of just ordering everything from Kilnlinings has saved mucho head scratching, wasted materials and potential cock ups. It's been a relatively simple build, with Liam at the end of the phone for idiot type questions which always arise for the novice builder :-)
|
|
|
Post by cannyfradock on Apr 25, 2012 16:37:50 GMT
Looking great!!!
I bet you're just itching to bake your first pizza.
Terry
|
|
|
Post by jonnycj on Apr 25, 2012 18:44:33 GMT
I am - but want to get the oven finished first ! Tempted to do a test pizza, but the weather forecast is miserable for the next few days, so decided to get it all finished.
|
|
|
Post by veauifru on Apr 26, 2012 6:55:52 GMT
The fire blanket looks very thin compared to the stuff i have seen that is a couple of inches thick. What type is it?
|
|
|
Post by jonnycj on Apr 26, 2012 17:57:59 GMT
This is the blanket I used kilnlinings.co.uk/body-soluble-blankets/body-sol.-blanket-1100gd-14.64m-610-x-13mm-density-96kgIt's body soluble, which is important as these things are potentially toxic and any particles that get into the body dissolve and are excreted within 10 days. I've used 3 layers of the stuff, so combined with proper fire bricks and two layers of thermally insulated render it should do the trick. Today's progress.. There's one more layer of render to go on and then paint and then we're there ! Just wish the rain would p:ss off !
|
|
|
Post by bookemdanno on Apr 27, 2012 12:17:57 GMT
What was the render mix again?
|
|
|
Post by jonnycj on Apr 27, 2012 18:41:23 GMT
Render mix is this stuff kilnlinings.co.uk/castables-refractory/castable-kl16fIt can give a very smooth finish if you put it on with a bit of skill. The height ratio between inner and outer leaves was around 80% - not ideal considering how much time and effort has gone into the build. I therefore came up with a solution using a piece of cal sil board cut to give the perfect 63% ratio. One thing that was troubling me however and that was beer can chicken ! I didn't want to be constrained by the arch height and not be able to get a leggy bird in there, so have come up with the perfect solution. The cal sil board is going to be faced front and back with 25mm fire bricks and will be removable ! It'll sit on top of some fire bricks we've put into the front corners (cut on a 45 degree angle) and will have right angled feet so that it stands up on its own. This gives me the option of having a high entrance for easy access and a low entrance for perfect cooking conditions :-) Now ready for a coat of masonry paint. Anyone got any suggestions for a colour ?
|
|
|
Post by cannyfradock on Apr 27, 2012 18:56:24 GMT
Jonny
I like the idea of you additional removable cal-cil board. If can also act as a rebate for a door if you ever decide to bake bread.
Any of the colours of your back wall would be ideal for the finish. You will always get some discoloration on the top of your arch from cold firing.....but I always like seeing that. It's a mark of a decent hard working oven.
Great build
Terry
|
|
|
Post by jonnycj on Apr 27, 2012 19:00:55 GMT
Thanks Terry - the removable cal sil was a 3am eureka moment. Good point about the back wall colours.
Going to make a door with cal sil as a centre, wooden outer and steel inner. I need to find a high temp thermometer to build into the door.
Also need a bit of decent weather !
|
|
|
Post by cannyfradock on Apr 27, 2012 19:28:34 GMT
|
|
|
Post by tonyb on Apr 27, 2012 21:57:45 GMT
Jonny, the removable calsil puts you in a perfect position to clarify the issue of the 63% rule of thumb. If you feel willing to try it would be interesting for you to compare building the fire with and without the calsil in place with your personal opinion of whether it makes much difference.
|
|
|
Post by jonnycj on Apr 28, 2012 16:23:41 GMT
Happy to be a guinea pig ! Need a few firings to get things up to temp and then will try some test runs.
|
|
|
Post by jonnycj on May 4, 2012 19:59:45 GMT
Pretty much done now ! Having a test cook of the first pizzas tomorrow :-) Just need to know if I need a specials heat resistant paint to go on the render ? Missed a trick I think by not putting a colour into the final render coat.
|
|
|
Post by cannyfradock on May 4, 2012 20:16:19 GMT
Jonny
That's the dogs bollocks of a Wood-fired oven.....many thanks for sharing your build with us.
With your insulating blanket ...and vermecrete the top of your dome should only get ever get hand warm, so you should be able to use any waterproof masonry paint you choose.
I always say.......slowly slowly with the curing fired. It's amazing how much moisture needs to be driven out of your oven before it's first full firing.
On the FB (American) forum they say cracks are par for the course with wood-fired ovens......due to the nature of the contrasting heat that these beauties produce, they may appear.....or maynot. Don't dispair if you see a few.....they're easily repairable and do not affect the integrity of the oven.
.....Happy bakin!!!
Terry
|
|