[Clayart] follow up on salt

Tue Aug 21 13:22:06 EDT 2018

Hi Robert - 
Sounds like a successful firing with a good compromise of effects.  I cannot imagine a salt kiln without 2.5x2.25 spy ports in order to accommodate draw rings. How did that happen?  I am not sure how large your ports are, but draw rings can be very small, with the cone pack placed just off to one side but still clearly visible, and the draw rings angled off to the other side.  I would never do a salt or soda firing without draw rings and my students were not allowed to fire without them, no matter how well they thought they knew the kiln.  

As I'm sure you know, the cone pack should never be placed close to the kiln wall in order to avoid inaccurate readings, so even with a very small spyhole, it is possible to place the cone pack just off to one side spaced back 4 to 6" inside the kiln, leaving plenty of room for draw rings. 

I am not sure what you mean by "potentially manic introductions of salt at the crucial ^9 bending moment."  Charging the moistened rock salt is always exciting, but I've participated in hundreds of salt and soda firings and have never experienced "manic."  Charging always stalls the kiln a bit, and unless you've got an over-powered kiln, there is plenty of time for relaxed salting as cone-9 starts to bend, usually with ten or fifteen minutes between charges. Pulling draw rings and quenching them in water to check salt deposition is such an important part of the ritual.

Try making some tiny draw rings that can be pulled through your spyholes.   
- Vince

Vince Pitelka
Retired Faculty, Appalachian Center for Craft
School of Art, Craft & Design, Tennessee Tech University
Now residing Chapel Hill, NC 27516
vpitelka at dtccom.net
sites.tntech.edu/wpitelka/

-----Original Message-----
From: Clayart [mailto:clayart-bounces at lists.clayartworld.com] On Behalf Of Robert Smith
Sent: Monday, August 20, 2018 7:55 PM
To: Clayart international pottery discussion forum <clayart at lists.clayartworld.com>
Subject: [Clayart] follow up on salt

Hi all,
With the fires raging in California, and so many of the clayart people being impacted, this follow up to the salt conversation is both of little import and inconsequential.
However, I did want to conclude the wonderful conversation/discussion about incremental salting, etc.
All went well. The firing was beautiful, soft and subtle, but not too much of either. There was not too much orange peel - which some students were glad about, and some missed - nor too much reduction, which, again, some students missed, and some were glad for. I couldn't be there for the final hours/saltings, but I understand that my head of department chose to remove the light reduction, in favor of a lighter coloration; and that a student, right at the end of the firing, decided to increase the salt dosage in the last application. At the same time, there was no dunting, shivering, bloating - nothing negative.
We started introducing the salt at 1600ºF, at 1 container of salt (1.625#), half in each salt port. We used table salt, which I think I will change to wetted rock salt in the future. We did the same thing at 1700º, 1800º, etc until ^9 was tipping, when we/they introduced 3.25# salt, half in each port, right there at the end.
Again, the results were luscious, but lighter than I would have liked. Had I not been committed to teaching at another venue that next morning when the firing ended, I would have done a few things differently:
I think I will start adding salt at 1800ºF, not lower; I think I would add salt at the same rate that we did, meaning at every 100º or so; I think that I will use rock salt, and not table salt; and i think that I might bump the total amount to 16-20#/firing.
All in all, there were no negatives, structurally or visually. The concept of slow salting (as in the ^6+ salt firings that I am more used to) works for all intents and purposes. I am now trying to discuss/discover/understand the benefits of firing this way. If there are none, then I will have learned that; if there are stronger benefits to salt/soaking at ^9+ that I remain unaware of, then I will hope to understand that as well. With our kiln, test rings are not possible:
perhaps with a new iteration of the kiln door down the road (currently hinged with refractory material/metal) we can increase the size of the peeps to allow for the extraction of the rings.
But this was a great and successful experiment, with satisfied customers, no negatives, and without the need for potentially manic introductions of salt at the crucial ^9 bending moment.
In this, we/I have learned a lot.

I send my best wishes and heart-felt condolences to all those wherever the fires have been raging. Your clay community really cares about you, and can help.

I appreciate all the feedback that I received early on, both the questioning and the supportive. All is good.
Thanks,
Bob
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