Calcium Aluminate - Ciment Fondu

[Mistertoy]

Think about using calcium aluminate homemade refractory mortar...

Does anyone know where to buy it in Brisbane ??


Thanks for your help
Brett

[david s]

Re: Calcium Aluminate - Ciment Fondu

Try total refractory management. They should have a calcium aluminate mortar ready mixed, but it will be way more expensive than the Portland, lime home brew mortar.

[cobblerdave]

Re: Calcium Aluminate - Ciment Fondu

dear Brett

I too looked into commercial types and too expensive. Used the home brew recipe and it works really well. Fireclay can be got from Dimore Brickworks for $30 a bag ( 1 and 1/4 used but sorry a mates got dibs on the remains) and the rest easy to get at the hardware. By the way I used washed sand by the bag (20kg) the type used for kids sandpits it made a finner mix which was easy to work with.

Regards Cobbler Dave

[Johnny the oven man]

Re: Calcium Aluminate - Ciment Fondu

try Kerneos on 0242722851, they make the stuff and should point you to a local seller.

[chidding]

Re: Calcium Aluminate - Ciment Fondu

I went for the premixed refractory option from SILA, picked it up at a pottery place in fremantle.. Yes it was $60 a bag, but at this stage its only going to take 2 bags to finish the oven. Which in the scheme of things isnt too bad.. I just figured i dont want to go through all this effort in building an oven, to have the mortar i made up myself go bad.

Choice is yours..

[Mistertoy]

Re: Calcium Aluminate - Ciment Fondu

I followed up Kerneos Australia today and they have referred me to Lyndons in Brisbane and I checked they do have Ciment Fondu

I have also done some searching and Kerneos is the new company which has evolved from the Lafarge company who originally patented and manufactured calcium aluminate cements. Kerneos has some data sheets that are good reading, one of the best one I found was:

http://www.cimentfondu.com/de/artisa...arConcrete.pdf

There is no mention of using lime which makes sense given the experience of others that have written on other forum threads about making home brew calcium aluminate mortars. So even though the pompeii plans indicate to use lime in the home brew calcium aluminate mortar, I think all the evidence says it is not required and I don't intent to use lime in mine.

Thanks
Brett

[david s]

Re: Calcium Aluminate - Ciment Fondu

http://www.cimentfondu.com/de/artisa...arConcrete.pdf

"There is no mention of using lime which makes sense given the experience of others that have written on other forum threads about making home brew calcium aluminate mortars."

They don't mention lime, but they do say you need to be meticulous to make sure there are no traces of Portland cement, which also acts as an accelerant. From my experience lime is way more effective in this regard, so eliminate it unless you want to mix a new batch every ten minutes. If it is really hot, as it may be by the time you get to starting your project, you can add chilled water to give you more working time.

[Johnny the oven man]

Re: Calcium Aluminate - Ciment Fondu

http://www.cimentfondu.com/de/artisa...arConcrete.pdf

"There is no mention of using lime which makes sense given the experience of others that have written on other forum threads about making home brew calcium aluminate mortars."

They don't mention lime, but they do say you need to be meticulous to make sure there are no traces of Portland cement, which also acts as an accelerant. From my experience lime is way more effective in this regard, so eliminate it unless you want to mix a new batch every ten minutes. If it is really hot, as it may be by the time you get to starting your project, you can add chilled water to give you more working time.

Dont tell anyone but...............................you can add sugar to slow down the set time on C/alum. cements.
And if you want to set it off quicker in winter............add Lithium Carbonate.

[david s]

Re: Calcium Aluminate - Ciment Fondu

I know cement mixers often carry a kilo of sugar in their trucks in case they get stuck and the load goes off. Apparently it is sufficient to stop the stuff going off at all. Johnny, how much sugar do you need to use and will it effect the end product ?

[Johnny the oven man]

Re: Calcium Aluminate - Ciment Fondu

Not much at all, 1 teaspoon is usually enough for a bag or two of castable.

[Johnny the oven man]

Re: Calcium Aluminate - Ciment Fondu

I know cement mixers often carry a kilo of sugar in their trucks in case they get stuck and the load goes off. Apparently it is sufficient to stop the stuff going off at all. Johnny, how much sugar do you need to use and will it effect the end product ?

LOL, they use the sugar for their coffee when they are stuck at a job.

[johnb]

Re: Calcium Aluminate - Ciment Fondu

There is no mention of using lime which makes sense given the experience of others that have written on other forum threads about making home brew calcium aluminate mortars. So even though the pompeii plans indicate to use lime in the home brew calcium aluminate mortar, I think all the evidence says it is not required and I don't intent to use lime in mine.

Thanks
Brett[/QUOTE]

I used Ciment Fondu (7.2 lt) mixed with Blue metal crusher dust (25 lt) water (3.9 lt)and mixed in 2 percent melt extract fiber from ANTEC. No lime. The dome was cast over a sand mold and is 100 mm thick. I have fired up the oven about 10 times and so far there are no sign of any cracks or spalling of the surface.
John.

[david s]

Re: Calcium Aluminate - Ciment Fondu

Hope it works ok, cracker dust is not a suitable aggregate for high temp. application. This brew is often used for the lining of chimneys. Maybe it will be adequate for WFO temps. Time will tell.

[johnb]

Re: Calcium Aluminate - Ciment Fondu

The Ciment Fondu web site rates basalt and granite to 800 deg C. My actual dome temp has never been over 600 C yet so heres hoping!

[Mistertoy]

Re: Calcium Aluminate - Ciment Fondu

Found the attached article which talks about accelerators and retarders - a bit techno but some of you might like it. P9 Figure 7 lists Lithium Carbonate and Lime as accelerators and citric acid and sodium citrate as retarders.
It also shows how temperature affects setting.

Made my first small batches of CAC homebrew with grog (crushed firebrick) instead of sand and fireclay. The first small batch I didn't use fireclay and found I really needed to wet the grog and let it absorb some moisture before mixing.
The next few mixes I wet the grog and fireclay before adding CAC and water which worked a lot better.

Set time was over 2 hours at < 20 celcius which is pretty much what the datasheet says. I will try a batch for interest with quarter the lime of FB recipe as others have used.

Brett