Hi all from Aussie

[Aussie Pete]

Re: Hi all from Aussie

good advice there david, thanks very much.
1 question...even if its a hot day, and i use chilled water with the mix, and mix only small amounts as i go, when i've finished the dome, do i only need to lay plastic over the top, is that enough to help stop it drying too quickly. I do have a gazebo over the top of the oven, so i suppose it should be enough, maybe a sprinkle of water over the top every now and then, what do you think?

[david s]

Re: Hi all from Aussie

I suggest you mix up only half a bag at a time using the manufacturers recommended water addition. With the mix fairly stiff it will stand up vertically without the need for an outside mould. As you get the feel for the stuff you can mix larger amounts. If it gets a bit stiff wriggle it in your hands and it will become more fluid again. If it is hot use chilled water to get more working time. Good luck.

[david s]

Re: Hi all from Aussie

Check the manufacturers recommendations on curing. I'm pretty sure it's calcium aluminate so 24 Hrs should be all you need.

[Aussie Pete]

Re: Hi all from Aussie

sorry David, yeh, i have pyrocrete mix, (just add water),i'll be using that to form a cast dome myself. (layering it over a sand dome).
I know it goes very hard pretty quick, so i'll keep plastic on it for atleast a few days.

[david s]

Re: Hi all from Aussie

Sorry, just re-read your thread, when you said "cast dome" did you mean casting, or are you doing it all in brick?

[david s]

Re: Hi all from Aussie

Castable refractory (calcium aluminate cement) does not require extended curing like Portland (calcium silicate cement) . You just cover it for 24 hrs and it has achieved max. strength. If you plan on making your own castable with lime and Portland cement it will be slow to cure. I'd cover that mix for two weeks.

[Aussie Pete]

Re: Hi all from Aussie

well...she's been raining pretty hard here all weekend, so didnt get to form the dome yet, hopefully next weekend with any luck.
What is the suggested time to allow the cast dome to set?
I will place plastic sheet over the top of the dome once finished to keep moisture in for a few days atleast, then i will take it off to fully dry.
I think i'm just going to make a butterfly damper in the flue, seems the easiest thing to do. Still after a good idea though.

[Aussie Pete]

Re: Hi all from Aussie

I had another look at the arch tonight after work, all seems good, (its still up anyway). I will probably do a bit of chipping & grinding the old mortar of and tidy up the arch on the weekend.
When i make the sand mold for the dome part, how long should i let it sit & dry before pulling all the sand out & cleaning up inside. Would a week be too much?. I'm guessing it will probably be ok within a day or 2.
not that i'm in a hurry or anything, just wanna do it right.
I am going to be placing a couple of thermocouples in the dome and probably the insulation. I know a lot of guys on here are saying "you dont need them"...and i know this but, i have a chance to use some and all the wiring for free...."so why not".
I'd really like to place them somehow so i can replace if need be at a later stage...can anyone help me with pictures of ways to make them replaceable.
I was thinking of some sort of stainless steel sleave to put them into, but doing that, how will that effect the dome as far as losing heat & having holes around the dome?...would it be enough to really worry about?

[brickie in oz]

Re: Hi all from Aussie

As soon as they get it right, promote them to Brick Tender. No more money just the title They will take a little more pride in their work Then maybe you want have to hire so many "labourers"

Just kiddin' Al, Brick Tender (Brick Layers Helper) may just be a local title. As General George S. Patton was quoted as saying (He was addressing a UK audiance at the time) "We are two countries separated by a common language"

I told one bloke that if he could mix 3 consecutive batches Id give him a mud badge, kind of like what you get in boy scouts for completing a task.

Well the day came and he actually did mix the said 3 batches so I presented him with his mud badge, it was 3 crossed trowels kind of fluer de lis style.

He was over the moon and took it home to show his flat mates, they all pissed themselves laughing of course, but he was proud....

[Gulf]

Re: Hi all from Aussie

Getting the mortar just right is one of those things.....
Every time I get a new labourer to mix the mortar you have to tell them how it has to be to suit yourself, they bitch a lot of course.....

As soon as they get it right, promote them to Brick Tender. No more money just the title They will take a little more pride in their work Then maybe you want have to hire so many "labourers"

Just kiddin' Al, Brick Tender (Brick Layers Helper) may just be a local title. As General George S. Patton was quoted as saying (He was addressing a UK audiance at the time) "We are two countries separated by a common language"

[brickie in oz]

Re: Hi all from Aussie

You can chip it or grind it.
I usually try to take the arch profile out the next day to make it easier to clean up.

[Aussie Pete]

Re: Hi all from Aussie

its definately not a profession you could jump straight into and start building a house.

I have formed the arch now, and i took the arch support away from the arch and ...'hey presto'...we have 1 arch standing up. (pheeewwww).
1 problem i have now is because i let it set over the weekend there is now some extra mortar slag around where the arch stood, it looks a little messy, what would be the best way to clean up hard mortar on the bricks and in the gaps...would chipping away be ok, or maybe grind away until smooth, (being careful not to grind the bricks)??
Apart from the bits of slag around...it looks pretty darn good for a novice.

(this is my first arch i've ever built)....

[brickie in oz]

Re: Hi all from Aussie

Getting the mortar just right is one of those things, you have to allow for the bricks, the weather and the way you like it.
One brickies mortar wont suit another, Ive had other brickies help me and vise versa, and we all complain about the others mortar.

Every time I get a new labourer to mix the mortar you have to tell them how it has to be to suit yourself, they bitch a lot of course.....

[Aussie Pete]

Re: Hi all from Aussie

Too runny is not good either - so try to get a nice consistency - you'll know when you have it. This link has a bit about mixing mortar - or brickie might give a short tutorial

it was runny, but i wouldn't say it was extreme runny, enough to pour into the gaps of the arch.
it still set pretty quickly, so i still had to move quickly once it was in contact with the bricks...they really wick that water away huh..It has set rock hard, so hopefully it will be ok when i pull the arch support away...which probably wont be until the weekend now. Give it great chance of full cure i suppose.

[Amac]

Re: Hi all from Aussie

I made sure my mix was very runny.

Too runny is not good either - so try to get a nice consistency - you'll know when you have it. This link has a bit about mixing mortar - or brickie might give a short tutorial


Masonry - Fine Homebuilding Editors, Taunton Press - Google Books
Amac