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more ?s about wood ash

updated fri 29 feb 08

 

Tim See on tue 26 feb 08


Haven't had much of a response on the last question so maybe not much is known about that issue.
So how would anyone suggest testing a sample of wood to collect the ash. I want to collect it at
temperatures from cone 012 to cone 13, to see the difference in ash composition through out the
range. Has anybody else tested this? Are there ways to test the contents of "fly ash" the stuff that
land on the pots opposed to what is left in the ash pit of a wood kiln.

I feel there is a significant difference in ash from wood burnt at low temps compared to ash from the
same wood burnt at high temps. I hope some of the super brains can add to a possible way of testing
for this.
Thanks in advance Tim see

Jeoung-Ah Kim on thu 28 feb 08


Dear Tim, I am a normal brain.
I do not know other way of testing for chemical analyses of ashes than use science laboratory methods such as XRF, XRD, or SEM, etc. However, I have read a book "Ash glazes" for the potters that you may use as a reference. Otherwise, there are many articles and books about ashes from field of inorganic or forest or environmental chemistry.
I am working with different ashes for clay bodies, etc. As you understood, the quality or chemical components of ashes are differ from temperatures but also type of kiln, firing methods, type of wood or bark, or between fly ash and bottom ash. You will get different quality of ashes by time to time you get from your own kiln too. I wonder where you are going to use wood ashes. I think you have to concern the trace metal levels in wood ash in case you are purposing to use it for functional pottery, for example of Pb content in ash should not be exceeding 100 mg/kg (in Sweden). The regulation may be different in USA.
Best regards,
Kim
___________________________________________________
Kim Jeoung-Ah, Ph.D
Post doctoral researcher
HDK, University of Gothenburg
Box 131, SE-40530, Gothenburg, Sweden
Tel: +46 31-7864771
Mobile: + 46-739849906
http://www.hdk.gu.se/fou/forskning/kim/index_e.html
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Tim See wrote:....
So how would anyone suggest testing a sample of wood to collect the ash. I want to collect it at
temperatures from cone 012 to cone 13, to see the difference in ash composition through out the
range. Has anybody else tested this? Are there ways to test the contents of "fly ash" the stuff that
land on the pots opposed to what is left in the ash pit of a wood kiln.

I feel there is a significant difference in ash from wood burnt at low temps compared to ash from the
same wood burnt at high temps. I hope some of the super brains can add to a possible way of testing
for this.
Thanks in advance Tim see


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