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alexi82 01-07-2013 01:12 AM

clay for homebrew mix
 
Hi guys

this time round I am going to use the homebrew mortar mix instead of paying 40bucks a bag for ciment fondue.

question is, is clay from a pottery place suitable? They say they use it by mixing with water, shaping, then firing at 1000degrees centigrade. Is this the same as "fireclay"? I.e. would it be usable for the homebrew mortar?

Cheers!

david s 01-07-2013 01:51 AM

Re: clay for homebrew mix
 
No, the powdered clay from a pottery supplier is probably not fire clay unless it is labelled as such. Personally I believe that most powdered clays would be ok up to the relatively low temps we fire to so it is really only price that is the consideration. Try bricklayers clay from building suppliers. It is incorrectly labelled by Cement Australia as fire clay, but should be ok and about the cheapest you'll get.

alexi82 01-07-2013 01:57 AM

Re: clay for homebrew mix
 
Interesting.

Not so worried about price for this component, rather do it right. was more that the pottery place i called didn't know what i meant by fire clay, and talked about this powdered clay, and I wanted to clarify.

This bricklayers clay sounds interesting. Anyone else used it?

alexi82 01-07-2013 04:27 AM

Re: clay for homebrew mix
 
Very interesting. I just did the same research (sorry should have done before hand) and have seen what you are referring to.

In my mind it should do it. On their MSDS it says "Clay is used for jointing refractory brickwork, pottery clay mixes, modelling and rendering"

Seems odd they would state it is good for refractory but it not be....

david s 01-07-2013 05:00 AM

Re: clay for homebrew mix
 
The product labelled "BRICKLAYERS CLAY - Fireclay" is not true fireclay. The confusion arises because fireclay in America and Europe is plentiful and cheap. It is basically a raw clay that is quite refractory. Unfortunately fireclay is much rarer in Australia and therefore quite expensive, presumably because it requires more processing. Bricklayers traditionally used small amounts of fireclay to add to their mortar to improve workability. Cement Australia have produced a product called "BRICKLAYERS CLAY- Fireclay" About three years ago I investigated using this product as it is way cheaper than the true fireclay I was buying from Claypave in Brisbane. At that time there were no specs provided by Cement Australia about their product, so who knows what it contains. So I rang their tech division and was told that it was not suitable for refractory use. I complained that the product was therefore mislabeled and misleading, but was informed that they were not about to change from one complaint. About a year ago specs appeared on the product and they now say it is suitable as a refractory.I have been using it ever since without any problems. However it is still not fireclay and a proportion of between 30-60% Kaolin does not make it fireclay either.
Hope this throws some more light on the issue.

david s 01-07-2013 06:34 AM

Re: clay for homebrew mix
 
Yes an assay could be useful, although if you make a home brew you are adding lots of silica in the form of sand. Fortunately as we only hit around 500C in practice there are no problems with eutectics.

deejayoh 01-07-2013 11:50 AM

Re: clay for homebrew mix
 
If you are cutting your firebricks, you'll have more "fire clay" than you need for homebrew. Cut base bricks and clean out your tray, and you are ready to go. Problem solved

alexi82 01-07-2013 02:24 PM

Re: clay for homebrew mix
 
Quote:

Originally Posted by deejayoh (Post 143608)
If you are cutting your firebricks, you'll have more "fire clay" than you need for homebrew. Cut base bricks and clean out your tray, and you are ready to go. Problem solved

Yea i've thought of this. The fire bricks are second hand from an old kiln so they should be fine.

Might try that first and see how much i get.

alexi82 01-07-2013 08:30 PM

Re: clay for homebrew mix
 
I called cement australia out of curiosity. Even though the MSDS says the clay has refractory properties and can be used in refractory mixes, they say on the phone that it doesn't. I informed the bloke that the MSDS says so...so he is off checking now......crazy.

david s 01-07-2013 09:00 PM

Re: clay for homebrew mix
 
Yes, that's what they told me, but the data sheet does say now that it is suitable. Maybe if folk keep complaining they'll do something. I think there is probably quite a wide range of composition between batches, as indicated "between 30-60% kaolin." It is after all primarily designed as an addition to mortar.

Did the bloke say he'd get back to you with an explanation? If so, ask him again, why is it labelled fire clay if it isn't ?


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