Hi all from Aussie

[robertjusher]

Re: Hi all from Aussie

HI
I am using it in the top of the oven entry.
I have not used gal. I know gal will do you in.
I think that once the rest of the dome is in place the steel will not matter too much. Looking at it again today it seems like it will not be needed after all is set and dry. Should be self suporting...

[brickie in oz]

Re: Hi all from Aussie

Pics.....?

[Aussie Pete]

Re: Hi all from Aussie

ok....finally glue'd down tiles, still needs a bit of cleaning up, but you get the picture.
Rains been good lately....(staying away), which has helped.
Back to work this week, then should be able to grout next weekend, then start the building. Told ya's it was a slow build..

Does anyone know anything about polishing sandstone tiles, they're pretty good, just thought i would try and clean them up before i seal.

i will lay down some cardboard to protect tiles.

[robertjusher]

Re: Hi all from Aussie

Pics tomorrow. got dark on me too soon,
Another question.
I have been using ryebond (airset) to set my bricks and then using homebrew mortar 3,1,1,1, mix to fill in the gaps and apply a top render.
Now I am nearing the top courses the angles are getting tighter and gaps bigger due to the dome closeing in. The air set is really only good for 2-3mm gaps so can I stop using it and just go to homebrew or should I use a refractory product.
I have made a sand form and the last few courses will just be sat on the form and mortar almost just poured in.
ANy thoughts?
Rob

[cobblerdave]

Re: Hi all from Aussie

I think you are game tileing then building the oven. I would wreck the tiles for sure if I tried that. I made a few batchs of home brew mortar today. Interesting stuff to work with. Seems and looks like mud to use. I think I got it in the gaps ok. Gave the outer surfaceI have done so far a light coat over the whole thing. Almost at once fine cracks as it dried. I will recoat the whole dome with 10mm or so when I finish. It does set hard fairly quickly and I am sureafter full curing it will be very solid. It's good to finally start a row of bricks with wedges. Kinda looks like what I was expecting.
Question for the wise.
The steel angle used in the plans, Will it rust away in the future? WIll it mater if it does. Going to be hard to replace it if it does.
ROb

Rob I have a rectangle entrance to my oven and 2 pieces non gal angle iron as the support. I was very aware that rust could be a problem and fitted both pieces so that they were not trapped by any brickwork with the hope that they could be tapped out and replaced in the future. 15 odd months on yes there is surface rust (more on the inner piece) its not major and I usually spray with mums cooking spray oil when I clean the oven cold.
With the sand mold you have the advantage of being able to remove it as the mortar sets and get in the oven to clean up and tidy any gapes. I have no experience with air set mortar ...but if its no good for gapes over 2 to 3 mmm go the home brew it will

Regards Dave

[Aussie Pete]

Re: Hi all from Aussie

ok..i'm a little stuck as to what i should do for insulation on top of the dome.
I will be using refractory mortar for the actual dome(approx. 2-3"), then will be laying atleast 2-3" of ceramic fibre blanket, then i will mesh that to keep it all in nicely, then...i'm stuck. A few on here have layed vermicrete then a mortar type top coat. I'm interested in laying dry vermiculite over the blanket (as to minimise water content in the mix's), because the oven will be an igloo style, will i need to make some sort of cage then mesh it in to trap the vermiculite in, or is there another way that i have missed.
is this method going to be ok, do i have the process correct.

i would rather not make a cage, if i can help it....a lot of mucking around.

being a novice, i'm open to slander....so hit me!!

Something else i just thought of.....is there different types of vemiculite, or is it all good.

[Johnny the oven man]

Re: Hi all from Aussie

The only way you could retain the dry V'lite would be to have verticle walls surrounding the dome.
A wet mix will soon dry out. Use Vermicrete, and then when you have dried it all out, use an acrylic render as the final coat.
Yes, there are different grades of V'lite, but its just different sizing.

[david s]

Re: Hi all from Aussie

I use 5:5:1:3 vermiculite, perlite,GP Portland cement, water. Using one hand on the outside and one hand making a horizontal ledge at the top. Apply one handful at a time and starting at the bottom of the dome work all the way around in a layer about 35mm thick. the water pretty much stays in this layer and you won't get too much being sucked into the blanket. You will think "this isn't going to work", but it does and it sets up hard enough so that you can render/stucco over it. The 50/50 vermiculite, perlite works way better than either of them alone for some reason. Try mixing up one batch of 10 litres and applying it then let it set for a day or two and see what you think. The more cement you add the less effective it is as an insulator. I dry mix the aggregate and cement then add the water. Leave the layer for a week to dry out before curing ,then rendering.

[Aussie Pete]

Re: Hi all from Aussie

thanks Johnny & dave, i think i will go the mix you mentioned dave, seems ok to me. I am sure there are so many different mix's people have used, but i'll just go with what has worked i suppose. Also 50/50 verm. you mentioned, is that verm. & perl. with water?
What type of shops sell verm & perl, is it nursery type places or bunnings.
How much would i need for approx. a 36" oven?
I think i am going to have some refractory mortar left over after completing the dome, could i use that with some verm mixed into it? If i was going to do that, which would be better to use verm or perl?
Come to think of it....whats the difference?

[david s]

Re: Hi all from Aussie

. Also 50/50 verm. you mentioned, is that verm. & perl. with water?
What type of shops sell verm & perl, is it nursery type places or bunnings.

Yes, 5:5:1:3 vermiculite, perlite,cement,water. Get it from nurseries, hydroponics suppliers or someone like Elders.
At a guess you'll need two 100 litre bags of each. They are about $35/bag
You could add the mortar to it but it will reduce its insulating capacity.

[cobblerdave]

Re: Hi all from Aussie

thanks Johnny & dave, i think i will go the mix you mentioned dave, seems ok to me. I am sure there are so many different mix's people have used, but i'll just go with what has worked i suppose. Also 50/50 verm. you mentioned, is that verm. & perl. with water?
What type of shops sell verm & perl, is it nursery type places or bunnings.
How much would i need for approx. a 36" oven?
I think i am going to have some refractory mortar left over after completing the dome, could i use that with some verm mixed into it? If i was going to do that, which would be better to use verm or perl?
Come to think of it....whats the difference?

Try Oasis hydroponics in Capalaba 100 ltr for approx $35 of different grades and sizes

Regards Dave

[david s]

Re: Hi all from Aussie

Perlite and vermiculite are both silica based minerals that fizz up like popcorn at around 600 C perlite is a better insulator when dry, although when cement is added there is little difference in their insulating capacity. The perlite contains more fine dust I've found so needs a bit more care to handle as it is irritating to breathe. Ask for a medium grade. The finer grades will require more water in the mix. The coarse stuff doesn't stick together so well. This is my experience, it may well depend on where your supply comes from, there is quite a difference in the characteristics of these materials depending on source.

[Aussie Pete]

Re: Hi all from Aussie

excellent!!...thanks dave, thanks david..
1 last question, then you guys can go to bed...

is it imperitive that both verm & perl are used, can i just use 1 or the other, whats the chemistry with using both....

nite nite

[david s]

Re: Hi all from Aussie

You can use one or the other, I just found that it holds together better if you have a mix of the two, it makes it easier to apply. The alternative is to add more cement, but that reduces the insulating capacity.

[Johnny the oven man]

Re: Hi all from Aussie

Pete, when you do the mix, add all your dry ingredients together, mix thoroughly and THEN add water.