search  current discussion  categories  kilns & firing - misc 

salt firing questions

updated sun 2 mar 08


Jeff Tsai on thu 9 may 02

So many questions...and I can't answer most...

Here are those that I can.

Firing a lid in place is great, but try putting three wads of a 50/50
alumina/kaolin mix between the pots and the lids. the lids won't warp too
badly and will still fit well, but they won't stick as readily. The sticking
is from the salt buildup right on the clay, wax burns off at very low
temperatures and then the salt seeps into the area that is in between and
sticks them.

You asked about white and gray spots...You've fired an atmospheric kiln
firing, expect variation, thats the whole point. You also said flashing
occurs mostly at the bottom and not on the walls or inside. Well, inside I
can understand. The salt, even when vaporized has a hard time reaching the
interior walls. Why the outer walls are blank is beyond me. Space out your
work more and you'll get heavier salt on the walls. Or for more flashing
a avery style slip, condense the pots tightly so the flame really has to
along the sides of the pots. The best variable flashing I've seen is from
tightly stacked work.


MT Hannigan on fri 29 feb 08

These questions are for all you salty dogs... Mel, please chime in--
you are one of them! I'll be using a propane-fired salt kiln for the
first time this summer and am doing a little research.

1. Is it possible to single fire when using salt or do you recommend
bisquing first?
2. Do you use flashing slips? If so, which recipes?
3. If you use glazes, which work best?
4. Does salt react well with oxide stains applied on the unglazed
clay body?
5. What process do you use to "apply" the salt? Shoveling in dry
salt, spraying a supersaturated salt solution, spraying salt solution
plus woodchips and optionally whiting, spraying a combo of salt and
soda, etc.?
6. Do you recommend using plain old rock salt? With iodine or
without (kosher)?
7. What cone 10 claybodies do you recommend (stoneware--iron, no
iron, porcelain)?
8. Is it true that salt firing is no more "toxic" than soda firing?
I've heard the warnings about deadly chlorine gas and hydrochloric
acid, but water evaporates instantly at 2110 degrees and anyone with
a swimming pool knows how quickly chlorine dissipates in sun and
air. Even so, is enough salt used to cause a problem? I'll be way
out in the boonies, so it's not an issue for me, but just wondering
what the actual emissions toxicity is.
9. If you had one tip to give a newbie on salt firing, what would it
10. What is the best book on salt firing?

Thanks, y'all!

Teri Hannigan