Tuesday, 8 April 2008

soda ash - where from, how, and what is it really?

The early part of February was taken up with investigations into soda ash, that versatile white powder used not only with fibre reactive dyes as a "fixative" but also as a traditional and versatile household chemical. The article was published in the March 2008 Batik Guild magazine and is also available on my website. There was a lot for me to get my head around, and indeed I needed (repeated) assistance to grasp some of the chemistry. Looking back to my first delvings into soda ash last July I realise that what the article doesn't do is assess the sustainability of using the chemical - in end use in dyeing and scouring (or by inference household use) and through sourcing and manufacturing. The trouble is I'm not confident or clever enough to draw conclusions, only to take them from published research. And I don't know if there is any.

However, I have no problem 'feeling' my way... science is all very good and proper but there is nothing like trusting instinct for getting it right.

After I'd finished the article I sat back and while resting my tired brain considered my earlier thoughts on the white stuff (pre-July 2007). I hadn't really thought about it, of course, but had a vague inkling it was naturally mined something like salt, say. But without any regard for resource sustainability. So my research has left me gobsmacked!

Of the three processes - manufactured (as in UK), mined (as in eg, US and Kenya), and 'gathered' from kelp or salsola ashes (the Old Days) - I cannot say with any certainty or feeling which is the most sustainable. But I've a feeling that at quantities produced globally today, none are. In line with everything else... I feel very uncomfortable at the thought of ripping out Mother Earth's innards, as required to retrieve limestone and rock salt for manufacture (but recognise my hypocrisy as today I put 33 more litres of petrol in my car without flinching). I'm less sensitive to surface mining of trona or natron as they are naturally renewing resources, but I feel Nature is hard pushed to keep up with our consumerist demands. Burning plants would seem the most eco-friendly resource as their annual replenishment is easy to gauge and thus Nature would set the limits. But... 'society' would collapse and (new) resource wars break out if this became soda ash's only source.

I need help to get answers, obviously.


Helen said...

As always Robin your blog gives me mcuh food for thought. It had never occured to me to question the use of soda ash, which I use in indigo dyeing. I increasingly use wood ash lye for othe types of dyeing, mostly for fermenting barks for dyes. The main problem is knowing what is the pH and maybe I need to invest in a pH meter and then use woodash lye. However this are chemically different form soda ash ( washing soda) This of course requires me to have access to the ash from wood burners. I burn wood in my studio but not everyone has access to it. hmm! much food for thought.

Robin Paris said...

It would be interesting to hear how wood ash lye (potash) works instead of soda ash with indigo, Helen. Do let me know if you try. I'm not sure how relevant the sodium or potassium content would be or whether it's the carbon bit which is helped along by the extreme reactive actions of sodium and potassium. I would have liked to have gone into this more, but the article was already a bit over length and it would have been slightly off topic...

Anyway, it's great that you already have a use for your woodburner ashes.