Hi all from Aussie

[robertjusher]

Re: Hi all from Aussie

Thanks Al
I gave it a good going tonight with a powered mixer ( work drill) and seems ok. Still quite thick. I did a few bricks tonight on the arch , so I see how it goes. It had 10mm or so of liquid on top and steadly got stiffer towards the bottom. Any thing less then perfect and the drum goes back. I don't need help making a mess of this.
Aussie , I have not got insulation yet. I will have some down time soon to sort out the last of the shopping list. Still to choose tiles, pavers,etc... Igot 75 mm thick 230 sq bricks for my floor. should hold plenty of heat.
Rob

[Aussie Pete]

Re: Hi all from Aussie

Rob, our decision to go the 230 SQ fire bricks 3", is something i'm interested to know if is the right one or not (is there a right & wrong answer??). Majority of the builders here just use the 230 x 115 bricks on their side or flat, is that because:

a. all they thought of
b. couldn't get anything bigger
c. is all they could get.

what would retain heat better, a large surface area brick, or more smaller bricks?. Does it even matter?

My thinking was it would retain and capsulate more heat because of the surface area. Surely a larger brick would retain more heat than a smaller one.

I've done no further work on my oven, work . Unfortunately work is a necessary evil. Hoping to do more work on weekend, hopefully get most of tiling on base done or even finished, will post more pics as i go (if i remember).

Al, i have a question for you ( or anyone for that matter)..... as you know i have the sandstone tiles on the top, in my lack of tiling professionalism the tile glue wasnt as thick as it probably should of and a few of the tiles have slightly (ever so slightly) sunken, so that a few of the tiles arent exactly level, (nothing that requires pulling them up or anything), how or what can i do to fix it up. My finished effect will be grout in between the tiles (not sure of color) & the grout nice level & flat, then i'll seal it. Nice & flat, so i can move plates & glasses around easily without them catching on the tile edges.
I've thought of sanding the tile edges down a bit, so there all nice and flat, but not sure on what type of sander or how rough to go, would i need to sand then do some kind of polishing to it...just not sure. the tiles have got that nice rainbow effect through it, so it should still look normal even after sanding.

Any thoughts??

[brickie in oz]

Re: Hi all from Aussie

Cant help with the tiles sorry, not my area of expertise.

[brickie in oz]

Re: Hi all from Aussie

I gave it a good going tonight with a powered mixer ( work drill) and seems ok. Still quite thick.

Dont get it in your eye or its a trip to emergency.

[robertjusher]

Re: Hi all from Aussie

HI Aussie Pete.
I used 230mm sq becouse I thought it would be easier to use less bricks and fewer joints.
I had a bit of a play with mine this afternoon and the 230sq's might not have been that good an idea. I tried my best but seem to have gaps betwwen them apx 1mm at the widest. The bricks are crap, not square, not straight and have curved edges.
But I hope still work well.
Seems to be flat and no ridges to catch a peel. If not I can pour a 15mm thick refractory mortar base over the floor , but should be fine......?
I got my arch started and 2 rows around the base tonight, I need to work out wedge sizes to begin the next course.
I have a question for the group-
After the dome is built I then want to fill in the gaps with homebrew mortar. How do I ensure that when rendering the mortar over the brick that there is no air pockets in the narrow gaps at the points where the bricks join.
I am thinking that pockets of air will cause expansion problems when heated and cause cracks?
Is this a problem or am I just dreaming up a new problem?

Thanks for the eye tip AL!!
Rob

[Aussie Pete]

Re: Hi all from Aussie

Not sure what bricks you got then, mine are perfectly flat & straight edge (not rounded), & they seem to be pretty square, and they butt up to each other very nicely. I wouldn't worry too much about a little gaps, you need that for expansion anyway i think.
With the dome, dont you lay the bricks with a bit or mortar as you go around the circle...(not sure though), that would eliminate air gaps between the bricks .
wheres the pics Rob??

[david s]

Re: Hi all from Aussie

The larger the pieces of refractory are the more likely they are to crack. Having said that 230 mm square is not really large and I think you should be quite ok. It is better not to mortar the floor bricks IMO because the gaps allow for the expansion movement. The gaps will soon fill with ash anyway. If you ever have to replace any of the floor bricks, which is unlikely, it is much simpler if they are not mortared.

[robertjusher]

Re: Hi all from Aussie

Thanks David
I kinda figured ash would fill the gaps. They are not that big but I am a little annoyed they are there.
I need to strat working out the flue joint and inner arch/ dome joints. I am still trying to cut as few bricks as possiable due to the only method I have is a 4 inch grinder anf diamond blade.
Anytips of rendering the dome with homebrew mortar to avoid air gapes?
ROb

[robertjusher]

Re: Hi all from Aussie

HI Pete
As you go around the circle the inner face of the brick touchs the next brick, no gap, but the outer face of the brick has a gap due to being on the outside of the circle.. The plans show just filling this with mortar, but Ithink this could cause a air pocket.
The 230mmsq I got are the end of the run as I was told, very old stock and they are not making more..
I will try to get pics soon. Just getting home from work and hooking in till dark. Got to get soem done when I can and today it was not raining !!!
Rob

[david s]

Re: Hi all from Aussie

Rob,
Use something like a 1/4" steel rod to poke that homebrew into the spaces between the bricks.
Dave

[cobblerdave]

Re: Hi all from Aussie

Gudday

Use a "clip lock" kitchen Bag fill with mortar cut off one corner and use like a kitchen piping bag .....works like a charm. Also use "fine washed sand" probably marked as suitable for kids playpits at you local bunnings in 10 kg bags....makes for a nice plastic mortar. Mix small amounts in 20 ltr drum using "mums" tupperware continer" as a measure and an "el cheapo" paint mixing stirer on your electic drill....you will not waste any mortar that way. Dont forget though ....let the inside brick edges touch ....no mortar if possible and fill the gapes in the brick backs ....same for you dome and arch.... it will have it max strength that way.

Regards Dave

[brickie in oz]

Re: Hi all from Aussie

After the dome is built I then want to fill in the gaps with homebrew mortar. How do I ensure that when rendering the mortar over the brick that there is no air pockets in the narrow gaps at the points where the bricks join.
I am thinking that pockets of air will cause expansion problems when heated and cause cracks?
Is this a problem or am I just dreaming up a new problem?

You can either just make a sloppy mix and sponge it on, or get a plastic bag and cut a corner off icing sugar bag style, fill it with wet mud and ice the dome.

I dont think any air pockets will matter too much.

[robertjusher]

Re: Hi all from Aussie

HI
Thanks for the advice guy's
I hope to get the first layers rendered with homebrew tomorrow.
Got to hook in while I can.
Rob

[david s]

Re: Hi all from Aussie

rob, give it at least a week to harden and dry. Because of the lime in the mix it takes longer to harden and allowing the weather(ha, ha) to do most of the water elimination is safer.

[robertjusher]

Re: Hi all from Aussie

HI
I hope to render each layer the day after I lay the bricks.
The whole oven is some time away and I plan on leaving it for a few dry weeks before lighting any fires and going real slow. After the oven is built I still have to finish render on base, add sink and plumbing, paint, tile, pave the floor, clean up mess and then get to insulation, etc...
Going to be a long build, and a another wrist/hand opperation next Friday to slow me down some more.
Good thing I have the pizza stone to get me by.
Rob