sand under firebricks?

[cobblerdave]

Re: sand under firebricks?

Gudday Poetryart
In a perfect world you should have oven dome and dome insulation sitting on your slab insulation...but sometimes the world less than perfect.You can operate with the dome insulation outside of the slab insulation I'm sure
If it was me I would first consider taking the oven down in size by 2 ins you'll lose a little oven entrance height but this would be only ay 3/4 of an inch.
Secound perhaps you could use some of the FB board from the entrance area outside the oven dome itself to fill in the gapes.
Lastly be patient and obtain some more FB to extend what you have got.
What ever you come up with try not to have the firebrick hearth in contact with your slab you lose a great amount of insulation value in those few ins

Regards Dave

[Poetryart]

Re: sand under firebricks?

Great minds think alike...I brought in the inside diameter by about a half an inch, cut some of the corners of fb board that weren't under the floor and placed them where I had firebrick. It's not perfect, but i think it will work. There's only one place where I had to put a firebrick for support under the floor which is under the half soldier course and it's only a couple inches. I cut the half soldiers, as well as the next round then mortered the soldiers in place. The brick store here swore that I needed stuff called Heat Stop for the mortar, it's pretty thin stuff, hope I did it right, I'll know in the morning...
I made the mistake of researching the forums and found Les' photos of his build. Geez, he set the bar way above my head. No chance mines going to be so gorgeous. Sigh... Oh well.

[cobblerdave]

Re: sand under firebricks?

Gudday poetryart
You have got to keep it in mind that as long as the oven inners are built of good materials and correctly it will work....no one sees the inside mainly the outer of your oven. They have no idea the wheather the bricks are individually
cut to each angle or not. Now I'm not saying I dont admire the workmanship but not for me. I can't wait to see the outer of yours!
If you want to see the thread of my oven it's dave's build in the Australian section of the forum. I have tried to get an earthy look... plenty of different colours and textures to the brick and matt finishes to the stucco. Worked for me and covered my less than perfect briclaying skills! Let me use a lot of recyled materials as well most of the stand and oven outer is recyled.
Heatstop not sure what that is from my perspective you cant beat the hombrew mortar from the forno plans its cheap, simple to use and above all a proven product.

Regards dave
hand on the mend...plenty o little tingles and pains looks like the nerves are connecting up again.Signed up next Feb to complete my full qualifications as a Bespoke Shoemaker they have recognised my previous work and experience and I have very little to complete to finish

[angel123]

Re: sand under firebricks?

I agree with using the fire clay..And in the beginning i was as doubtful as you..And finally i took up my friends suggestions and put fire clay..From past one year it is quite fine..

[cobblerdave]

Re: sand under firebricks?

Gudday Poetryart

Hows progress???
Would love to see some Pics too!!!

Regards Dave

[Poetryart]

Re: sand under firebricks?

Holidays, 28 people for thanksgiving dinner, impending deadline for big sculpture, rain, too much to do....yet... I did manage to mortar in the entry bricks, and figured out my archway! It's s'posed to rain, with possible snow, for the next couple days. It's covered with a tarp at the moment and when I get to uncover it, I'll take photos...in the meantime, I'm studying all the pizza making posts and drooling profusely...
I'm frustrated that it's not done yet, I'm not a delayed gratification type of girl, sigh...I used to wonder why it took so many people so long to complete their ovens... Now I know. Life gets in the way.
Even in it's unfinished state, it impresses my friends.... Lets hope the pizzas do too! Lol.

[cobblerdave]

Re: sand under firebricks?

Gudday Poertyart
How things going? survived the winter? back to oven building yet?
Summer in Brisbane has again been wet.....soaking oven again ! waiting for winter cool and dry.... perfect for wood ovens in QLD Aust.
Hands on the mend....still gets sore....but out of bandages so I feel normal again


Regards Dave

[Poetryart]

Re: sand under firebricks?

Hey Cobblerdave! Yep, back to oven building. I've got a question for you, though. I hope I didn't mess up...I put in 4 inches of insulating concrete this afternoon. I built the oven on the fb boards and fire brick and needed to raise the rest of the platform/ hearth to match the level of the oven floor minus the dimension of the mortar and tile I'll put in for finish out. The concrete stuff doesn't seem to be setting up at all. It's still kinda crumbly feeling. It's also still quite wet. I did it to the consistency of oatmeal, so I don't think I did it too wet. What should I expect of the concrete?
Thanks, glad to hear your hand is healing well. - Poetryart

[cobblerdave]

Re: sand under firebricks?

Gudday
Now...have I got this right? you have used perlite/cement to raise the outer to height?
I only mucked around with perlite/cement but didn't use i in my own oven due to it being built during the biggest "wet" we have had here in QLD so all my insulation was "dry".
The stuff uses and retains heaps of moisture so its going to have to have a considerble period to dry out....all that water you have added is trapped in the tiny holes that gives the stuff its geat insulation value.
I've mixed up a batch and let it cure... it first appears to be softer than cement but will from all accounts support a full blown oven!!! ther'se heaps on the forum!
I'm not sure what your local conditions are in regards to climatic conditions but I pretty sure that the portland cement in that mix doesn't like cold conditions I'm pretty sure that it retards it curing. (We have the opposite it has to be covered and kept wet lest it cracks)
So I'd be patient and see how it sets over time... its to be covered in tiles so this will protect its soft surface!
Hope this helps

Regards Dave
PS No more excuses.....some pics...please
If you had trouble uploading them just ask I'm a computer illiterate so I could probally explain in English

[Poetryart]

Re: sand under firebricks?

Test - did this photo come through? ~

[Poetryart]

Re: sand under firebricks?

yippee! It did, it did!
The perlite/portland cement has been drying for almost 24 hours. There's still a little "crumbly" surface on top, except where I dumped the slush from the bottom of the wheelbarrow - seriously wet stuff - it's now the firmest. Should I go back and put a layer of soupy portland on top to seal it? I do plan to put some tiles on for finish. This weekend we'll put the FB blanket on, and the layer of portland/perlite on top of that. We still need to decide exactly how to do the flue. We'll stucco for the dome finish.
Don't laugh at the shape of my dome, btw, I know it looks a bit like a big zit...but that will get covered up. I hope....

[Poetryart]

Re: sand under firebricks?

another view.
i hope.

[cobblerdave]

Re: sand under firebricks?

Gudday
Thanks for the the pics... ovens looking good!!!....your on the home stretch now...

Regards Dave

[cobblerdave]

Re: sand under firebricks?

Gudday
Just hoping for a few more pics on your progress to date

Regards Dave

[big dumb & stupid]

Re: sand under firebricks?

Just to confuse you have you thought of using broken glass under your hearth, loves heat and if broken to very small pieces it will tick all the boxes.
Sri Lanken bakers use this method and they have some very hot/even ovens