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skywalker 12-18-2013 11:49 AM

Agricultural lime in home brew
 
What will happen if I used Agricultural lime in my home brew mortar? I'm way past the disturbing mistake where I just realized I used the wrong Lime.

I've already finished the oven and I've been cooking already. I have a few "normal" hairline cracks, which I'm not too worried about, but now I'm starting to lose sleep after finding out I've used the wrong lime... will it collapse? Did I severely shorten my oven's lifespan? or what?

I obviously did not do enough research on lime...

brickie in oz 12-18-2013 10:41 PM

Re: Agricultural lime in home brew
 
Quote:

Originally Posted by skywalker (Post 167012)
What will happen if I used Agricultural lime in my home brew mortar? I'm way past the disturbing mistake where I just realized I used the wrong Lime.

I've already finished the oven and I've been cooking already. I have a few "normal" hairline cracks, which I'm not too worried about, but now I'm starting to lose sleep after finding out I've used the wrong lime... will it collapse? Did I severely shorten my oven's lifespan? or what?

I obviously did not do enough research on lime...

I thought slaked lime was lime was lime? :confused:

skywalker 12-19-2013 04:46 AM

Re: Agricultural lime in home brew
 
I found out that slaked lime (Type S) is what you want to use. Not agricultural lime, which is what I used... I really would like to know what it'll do to the oven.

Tscarborough 12-19-2013 05:43 AM

Re: Agricultural lime in home brew
 
It is, but you have to actually slake ag lime, while Type S is already once hydrated, so simply adding water will slake it.

You should be alright anyway.

Greenman 12-19-2013 05:24 PM

Re: Agricultural lime in home brew
 
You will probably find that agricultural lime is hydrated. Like many things destined for agricultural use it is only processed to the form that meets the need of the industry. The lime bagged for domestic and construction use is likely to contain less by way of impurities but I don't believe that the different specification would make any difference in your application. Like Brickie said - lime is lime.

I am sure that your oven will be OK.

skywalker 12-19-2013 05:31 PM

Re: Agricultural lime in home brew
 
Thanks guys! Feeling a LOT better already!

Tscarborough 12-19-2013 06:46 PM

Re: Agricultural lime in home brew
 
Ag lime is hydrated, Greenman, Type S is double hydrated, meaning 2 different methods to involve more of the chemicals in lime.

The difference is small but not insignificant, and Type S can be considered to be dry slaked lime, while ag lime should be slaked by immersion and time.

skywalker 12-19-2013 06:49 PM

Re: Agricultural lime in home brew
 
So I guess that just by adding water to make the 3-1-1-1 homebrew mix wouldnt be considered slaking wouldn't it?

wotavidone 12-19-2013 07:07 PM

Re: Agricultural lime in home brew
 
I thought about it for a while before posting this reply, because I did not want to dishearten you.
However, in the interests of making sure others don't have the same issue, I gotta say, lime ain't necessarily lime. I suspect it probably depends where on the planet you are.

Quote:

Originally Posted by brickie in oz (Post 167031)
I thought slaked lime was lime was lime? :confused:


"Lime" is a catch all term for the common calcium compounds.
The trouble is, there are many traditional names, that vary wherever you are in the world.
In the game of extracting lead, zinc copper and silver from ore by the process of sintering and smelting, we take care to distinguish the different types. The old nomenclature has potential to derail the process if the wrong lime is used in the wrong place. (It's not helped by the fact we tend to use all three common types in different parts of the process.)

In Australia:
There's quicklime, soft burnt lime, or burnt lime = Calcium Oxide.
There's slaked or hydrated lime = Calcium Hydroxide.
There's Lime stone, Lime Rock, lime sand, or Lime rock sand (lime stone crushed to our required particle size) = Calcium Carbonate.
The last one tends to confuse our new graduate Metallurgists the most, for reasons which escape me.

Quote:

Originally Posted by skywalker (Post 167049)
I found out that slaked lime (Type S) is what you want to use. Not agricultural lime, which is what I used... I really would like to know what it'll do to the oven.

This will depend on what they use for agricultural lime in your part of the world. The point of using lime in mortars is to use either burnt lime which will convert to slaked lime when you mix it with water, or slaked lime calcium hydroxide.
Either of those will, on exposure to the carbon dioxide in the atmosphere, slowly turn to limestone, calcium carbonate, as the mortar ages, adding strength as the process goes on.

If they use calcium carbonate for agricultural lime in you part of the world, like we do in Australia, no chemical reaction is going to take place and no extra strength is going to develop.

If, as Tscarborough says, agricultural lime in you part of the world is hydrated, you should see some contribution of strength from the lime.

However, don't forget you have used two other agents in your mortar that help harden the mortar - clay and cement.
If you used Portland cement, it's possible that we are going to find out if
there is any truth to the oft repeated assertion that pizza ovens get hot enough to break down the Portland cement over time.
Also, possibly not, as I expect you used clay as well. There must have been plenty of ovens assembled with clay as the only binder in the mortar.

Quote:

Originally Posted by Greenman (Post 167090)
You will probably find that agricultural lime is hydrated. Like many things destined for agricultural use it is only processed to the form that meets the need of the industry. The lime bagged for domestic and construction use is likely to contain less by way of impurities but I don't believe that the different specification would make any difference in your application. Like Brickie said - lime is lime.

I am sure that your oven will be OK.

As I explained above, slaked lime is lime, but lime ain't lime, and according to this explanation from the NSW department of primary industries, agricultural lime in Oz is limestone, not burnt or slaked lime. As you rightly assert, that used for agriculture has the least amount of processing they can get away with. I've used a lot of finely crushed lime stone, 3000t per month of minus 2.5mm at one stage, and when it's wetted it does not develop any strength at all.

Which liming material is best? | NSW Department of Primary Industries

Quote:

Originally Posted by skywalker (Post 167091)
Thanks guys! Feeling a LOT better already!

I apologise for disturbing you mood, but I really felt the issue needed to be explored further. I reckon your oven won't fall down anytime soon, regardless of what lime you used.

skywalker 12-19-2013 08:46 PM

Re: Agricultural lime in home brew
 
Thank you wotavidone for that thorough answer. Its ok I can take the honest answer and I did want to hear an answer like yours so we can make a useful thread for others that might do the same (gosh I can't be the only one, right?... right?).

I've searched a lot after I realized my mistake and nowhere did I find what happens if you do use Agricultural lime in the homebrew. I did find a lot of warnings agains doing just that (I should have done the lime research before). But no explanation of what would be the consequence.

What you say makes a LOT of sense. I have noticed a that my homebrew is not very strong. When I installed the chimney on the anchor plate, the bricks that the anchor is screwed onto came loose. So I had to glue them back together with high heat cement. Hopefully I did a good enough job with the brick work in the dome and it truly is self supporting.

I swear when, and if, it collapses or something, I will come back and update the thread for the greater good of having a record of it.

By the way, I got the Agricultural Lime at HD and the construction guy told me to look for lime in the garden section, so I went to the garden section. The garden guy told me, "oh yeah! lime, we have it pulverized and in pellets, I asked him if I can use this lime for masonry and he said "lime is lime", ironically, so I went with the pulverized lime (Agricultural lime, which is pulverized limestone).

Live and learn.

Lucas


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