Dale Neese on sun 11 nov 07
could be a time coming in your future when you will be mixing glazes
yourself. You have to have a tried and true recipe. One that you have tested
on your own clay body. Not all glazes will be the same from region to
region, clay body to claybody, glaze material etc. So test first. Find a
reliable glaze. One that works well with other glazes. Then purchase your
glaze materials. The larger the quantity the more saving on cost unless the
glaze you've decided to mix has 12 exotic ingredients. Identify all bags of
glaze materials so nothing is unknown. Make notes, keep a notebook, write
down everything.
It's time to mix. Turn off the phone, throw the cat out, and put a "do not
disturb sign on the door". Give this glaze exercise your complete attention.
Whip out the scales, check for their accuracy and get to work. Whether you
are mixing 3000 grams or 30,000 grams or more of a glaze establish a good
system for yourself and stick to it.
If this is your first attempt mixing a glaze don't mix too much. Just enough
to judge the fluid quality of the glaze suspension in the batch. Coating on
a dipped piece of bisqueware. You can use an instrument to measure exactly
the specific gravity, but I know by feel. I run my hands in the bucket of
glaze to feel the water content. I can feel when it's "right". You only know
this because you've done it hundreds of times as I have. Wash your hands in
a waste water bucket often, don't pour it down the sink! Spray or pour
vinegar over your hands afterwards. Notice how the Ph is changed and it's
good for your hands. Use hand creams when you are done. So if you are
alergic to many things DON'T DO THIS! Pottery is not a clean occupation to
begin with unless you are used to your glazes come from a jar. Be sensible
and have precautions. Wear protective eyewear and dust masks as I do.
I choose to mix my glazes with rain water because I have high alkaline well
water. There is a difference and it shows in the final quality of some
glazes, not all but some that I mix.
Measure each ingredient, place the called for amount in separate containers,
buckets, bowls, bags, whatever. Don't just dump them all in one container
together. I've made my share of measuring mistakes and sometimes they will
bite you and you end up going for the hammer and worthless buckets of crap.
5 ingredients, 5 containers. This way if you are interrupted in the middle
of measuring you can always go back and re check the amount in each
container before combining. Hard to separate materials when they've been
combined. Once you have the correct amounts from your tested recipe, put
some scoop fulls of each in a bucket with some water, not a whole bucket of
water but enough water that you know you will have to add more water because
of the amount of materials you are going to be using will be too thick. You
can't take water away but you can add it. Mix, mix, mix, all the materials
for the recipe in the bucket. Feel it with your hand. Or visually judge it.
Is it going to need more water? Stop. Don't add more water. Sieve it all,
press it through a 30-60 mesh screen into another bucket. Stop. Let the
glaze set over night. You will see next morning that the glaze, depending on
the amount of clay in the recipe will be thicker. Re-screen and add water as
needed feeling the glaze with your hands. Is is milk, cream, just short of
plain creek water? If you did a double dip on your test tile will it as
thick or as thin as your test? By feel is the only way I've learned to tell
if my glaze, for me, only for me is the perfect viscosity to use on my pots.
Dip, count, one thousand one, one thousand two, pull. I know this refering
to my notebook. Put them in a firing, observe the results, yes! it's the
same as what I've been using. Dependable beautiful glaze again. Consistancy
right down the line, "shake-mix well before using". Keep the lids on your
buckets. Mix good and check your viscosity before glazing.
DaleTex
"across the alley from the Alamo"
San Antonio, Texas USA
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