Oven Build 900mm - NZ

[kriso]

Re: Oven Build 900mm - NZ

After finally getting all the info on the lime front I have a better understanding between Hydrated lime (Ca(HO)2 calcium hydroxide) and horticultural lime (CaCo3 calcium carbonate).
I have just laid the first layer of firebrick for the base......

[kriso]

Re: Oven Build 900mm - NZ

John
Thought that I had stuffed up on the lime part, however the lime that Farmlands sells is hydrated lime. Went to the web site of McDonalds lime (McDonald's Lime | ONLIME | Home).

Hydrated Lime Ca(OH)2
Calcium Hydroxide Ca(OH)2
Common Names: slaked lime, hydrated lime
Available in Bulk or 20kg bags

They sell these at farmlands for $9.00 a 20kg bag.

I did some other checking on the horticultural lime which is CaCO3 (calcium carbonate) which will not work as you said like the hydrated lime Ca(HO)2 (calcium Hydroxide).

Glad that I double checked it and hopefully any others can benefit from this info.
Cheers
Kriso

[John French]

Re: Oven Build 900mm - NZ

Using cheap tile cutter - adequate. Relime try placemakers or PG Wrightsons. Both have 40 kg bags of hydrated lime ( Calcium hydroxide ) at reasonable price. Do not buy horticultural lime it is the rong product. Iam usinghomebrew which is working well.

[wemme]

Re: Oven Build 900mm - NZ

@gene, I have a Large CNC router Brilliant on things like this.

@Kris, Cheers i will need to give them a call i'm not having any luck here.

@Tscarborough, Cheers for the info. How do you make or apply the render does it leak or weather off over time or is it better to use stucko ?

[Tscarborough]

Re: Oven Build 900mm - NZ

Kriso, what you have is called "type S" double hydrated lime here. It is not the same as agricultural lime which is single hydrated. Either will work for normal low requirement mortar (like laying stone), but the type S is what should be used for refractory and render. You do not have to slake it for refactory, but should for render.

To slake, gently cover with water, no stirring, and keep it covered with water for at least 3 days. It is then slaked and can be used. To use, pour off the water, save it to use to cover over what is left over. So long as the slaked lime is kept covered with water it can be kept and used indefinitely.

Edit-and FYI it is low toxicity but is an extremely caustic alkaline. Be careful around it when it or you are wet. Dry it is no problem.

[ggoose]

Re: Oven Build 900mm - NZ

Hi Bart,
Nice looking forms...with what type of machine did you construct those? They look a little too uniform to be freehand.
gene

[kriso]

Re: Oven Build 900mm - NZ

Bart
Just got this off the net..... it's full of answers.......
Calcium hydroxide, traditionally called slaked lime, is an inorganic compound with the chemical formula Ca(OH)2. It is a colourless crystal or white powder and is obtained when calcium oxide (called lime or quicklime) is mixed, or "slaked" with water. It has many names including hydrated lime, builders lime, slack lime, cal, or pickling lime. It is of low toxicity and enjoys many applications.

I brought a 20kg bag of hydrated lime from Farmlands today for $9.00 (states on pack used in motar), good to see there is one thing in this build that is cheap, anyway I have just purchased a new diamond blade for the brick cutter and are just about to get into it.
Will Post a few pics soon
Cheers
Kris

[wemme]

Re: Oven Build 900mm - NZ

Hi kris,
Yes i will be using that mix. I'm not sure if the horticulture grade is what you need. i have to have more of a look but bunning no longer sell builder lime
i didn't use this mix to secure my base bricks though.
Regards
Bart

[kriso]

Re: Oven Build 900mm - NZ

Bart
Try farmlands or RD1. I have spoken with them here in Rotorua and they have hydronized lime which should do the trick if you are thinking of the mortar. I am picking us some tomorrow for under the fire bricks. I just got a 20 kg bag of fireclay from shinagawa. Are you making the 1 part cement, 1 part fire clay, 3 part fine sand and 1 part lime mix?

Cheers

Kris

[wemme]

Re: Oven Build 900mm - NZ

Hi John, Yeah has been a few rumbles....
How are you cutting your bricks?
And What are you using for mortar?
I went around to bunnings to get some builders lime and have had no joy.
Regards
Bart

[John French]

Re: Oven Build 900mm - NZ

Hey John,
where you get your bricks from, how are you cutting them?

I've had a look at Canterburyclaybricks they have a range of flu tile from about $8
(they have fire clay, firebricks and have a cast pizza oven for $800 but its made from crushed brick mixed with cement and only ~75 thick not sure if any good.)

Re materials have a look here...

http://www.fornobravo.com/forum/f2/building-supplies-nz-7192.html

I'm planning on using about 4-6 flu tiles from a few of the chimneys that came down in the earthquake. also going to use the clay bricks for decorative work around the chimney. No shortage of bricks since the quake. also have a good look at chimney pots on trademe. was thinking of using something like the ones attached however they look rather heavy and not sure if my structure would support the wieght. but they would look dam smart!

Regards
Bart

Using bricks from Caterbury Clay - they were the cheapest i could find. I did look at trade me but could not pick up enough 2 nd hand bricks. Canterbury Clay has some seconds going cheap but i decided not to risk them. I have been a bit disappointted at the number of bricks that are cracked or out of shape - i returned a few. Going to need some more. I have not looked at flue tiles / chimney options yet. The inner arch is my next phase as i am upto 3 rd ring. Brick work not brilliant but i think it will stand up as it has already experience 3 earthquakes over 4.5!!

[John French]

Re: Oven Build 900mm - NZ

John
What type of brick are you making your dome out of?

Kriso

Firebrick. Got from canterbury Clay bricks - who were helpful. However, these are expensive compared to US and not all bricks are equal. i had a few that we rather deformed or badly cracked. I am trying to avoid using these at the moment but i think i am going to need a considerable numbe rof extras

[wemme]

Re: Oven Build 900mm - NZ

Almost have the suport stucture complete.
with some luck i might be able to start preping bricks this weekend and may even start laying some. I was originally worried that we would have an issue with the dome/arch area but think with this form it should be ok.
Need to cut some holes in the arch form to make the drying and burn out easier.

[wemme]

Re: Oven Build 900mm - NZ

Hey John,
where you get your bricks from, how are you cutting them?

I've had a look at Canterburyclaybricks they have a range of flu tile from about $8
(they have fire clay, firebricks and have a cast pizza oven for $800 but its made from crushed brick mixed with cement and only ~75 thick not sure if any good.)

Re materials have a look here...

http://www.fornobravo.com/forum/f2/building-supplies-nz-7192.html

I'm planning on using about 4-6 flu tiles from a few of the chimneys that came down in the earthquake. also going to use the clay bricks for decorative work around the chimney. No shortage of bricks since the quake. also have a good look at chimney pots on trademe. was thinking of using something like the ones attached however they look rather heavy and not sure if my structure would support the wieght. but they would look dam smart!

Regards
Bart

[kriso]

Re: Oven Build 900mm - NZ

John
What type of brick are you making your dome out of?

Kriso