Welcome to our B.O.C. blog. Learn about the world of handcrafted ceramic beads, buttons, pendants & components from our talented and knowledgeable Artisans.

Third Friday Commercial Cone 6 Glazes

Welcome to the December post for Cone 6 commercial Glazes.
I'm going to continue my previous tests (the large cone 5 and 6 results soon).
But I was having some issues with some of my older Cone 6 glazes that were dried up and thought that since a lot of you might be having the same issues - we could discuss how to remedy it.
 Sometimes glazes just dry up a bit over time and need some extra water.
Always used distilled water, and not tap water because of the chemicals tap contains.
 When your glaze is wet, but chunky, you can get a larger mixing bowl,
Not to be used with food ever again,
Then add some distilled water, then mix.
 I like using this "milkshake mixer".
Again, once a tool is used on glaze it should not ever be used with food.
This one has a pulse setting that I like to use. 
I make sure to get all the chunks until it runs smooth like yogurt.  
 When finished, unplug the mixer before cleaning it.
I know at least two people that have thought, I'll just quick clean without unplugging it before moving to the next glaze, and they have had their fingers severely mangled. 
Not a good idea. Take the extra time and be safe.
So here it is, back into it's glaze container, ready for brushing application on to some pieces.
But wait, after it dried, there were lots of cracks. I guess it is too thick.
So do I add more water, or try something else... 
 I decided I didn't want to thin this out too much with water because it was already pretty wet (although thick), so I would give this Brushing Media a try…
See the directions online or on the container for how much, when and why.
This photo above is the glaze before adding the media (peaks formed and held well). 
 Added some of the brushing media (reminded me of separating egg whites).
 Just a spoonful dip into the container, then into the pint...
I used the spoon (non-food use) to mix in the media.
Looked pretty cool and it shows the state of the glaze consistency pretty well - thick and wet…
This is not a very smooth glaze. It is a satin matte finish. 
Then I went in with a brush and finished stirring, getting all the edges and bottom of the container.
It was so thin it could drip, not glop off the brush… 
Perfect (so I thought!)
I tested it on one of my pieces. Boy, this glaze was now a bit more wet than I wanted... 
 And it takes much longer to dry now.
On the left is the first coat, pre-brushing medium (big cracks)
On the Right is the second test, after adding brushing medium (less cracks).
 Here you can see a bit more detail of them together.
There are still some fine cracks on the right one with brushing medium.
So I'm not quite happy with it yet. Not sure if I can do much else for it now that I've added the brushing medium, except for order another pint to see if the glaze manuracturer has changed the formula up a bit to deal with this thickness and drying out issue.
Or maybe it is my clay body. It just might not be a good fit for this glaze...
 Here you can see how easy the glaze (pre-brushing medium) flakes off of the clay.
This is a sign that you should look for and realize that it might be a clay-glaze fit problem or a glaze suspension issue (most likely a fit issue).
Then there are glazes like this…
Rock hard (seriously - a hammer wouldn't dent this).
Into the old mixing bowl it goes.
With concerns of silica and creating dust, I decided that after a few good whacking attempts with this solid wood (the wood end was damaged more than the glaze chunk - which didn't even flake)…
I decided it was best to submerge this completely dry glaze chunk in distilled water.
And because I have cats and little ones (even though my studio has doors that are lockable, they can still wander in behind me and I want to avoid accidents) there must be lids for things like this.
After two to three days, it didn't look like there was much hope.
But I took my spoon and chipped away at the chunk under water.
Then felt that there were no really hard pieces that could damage my mixer, so out that came for a turn.
I wasn't too concerned about the amount of distilled water, although I did eyeball it and poured off a bit of it from the soaking chunk of glaze photo into the empty glaze container for temporary holding. That way I could add more if it was a bit thick while mixing.
And as you can see - it was pretty thin, so no extra water needed. There are still some bits of chunky glaze particles, but some glazes just have hard stuff in them. And you can't see it once they are fired.

If there was too much water (if my eyeballing was off), I would have just let the glaze settle after mixing for a couple of days, and pour the clear water off of it.

Which leads me to another situation - that I have no good example photos for.
What do you do when your glaze falls out of suspension?
You go to stir the glaze that "looks fine" but you hit a hard solid chunk of glaze at the bottom of the container…
First thing is to mix it good. Sometimes that is all a glaze needs.

But if it is settling while you are using it (I'm talking a glaze mixture here, not oxides or colorants) then you probably can use some Commercial Glaze Suspender.
A little of this (Bentonite) goes a long way to keep those particles in suspension.

I'm always on a quest to learn about different techniques to figure out issues in the studio to make my creative time better (I hate how fast a non-cooperative glaze can ruin good studio time).

So how do you deal with your glaze issues?

Any suggestions or expansions on to what I've written.
This knowledge is from my experience and looking around and reading directions, and seeing what others are teaching through their mistakes and successes...

5 comments:

  1. the glaze cracking off after it has been reconditioned is typical with some glazes..it's not about fitting the clay body in the normal sense..a fresh fluid bottle from the factory won't do this.. this reconstitued cracking glaze can jump off the clay during firing and also spread apart to expose the clay body..it's some water ratio thing that happens when a clay drys out and you rehydrate it. i googled and finally found some info about it..but can't remember where right now..

    ReplyDelete
  2. Great and informative post Marsha, thank you! I use all commercial glazes and so far water is all I have needed. But I do have a few glazes that I see that need a little more help so this post is very useful. I may have to get one of those hand held thingies for clay. Thanks again!

    ReplyDelete
  3. The process is very nicely shown through pictures here.It is not an easy task to make the clay pieces as we see and wear a lot of hard work and creativity goes into it surely.

    ReplyDelete
  4. Thank you for such a great post Marsha. Love your use of the kitchen tool I have and use for blending soups and sauces. They are quite inexpensive and getting one for the studio is such a great idea. I imagine one could mix glazes with it too, but for sure wearing a respirator. You know I love tools so this post is perfect!!

    ReplyDelete
  5. ou can also use epson salts to keep glaze in suspension. 1 T dissolved in warm water to 1 kg. (2lb)of dry glaze

    ReplyDelete

Note: Only a member of this blog may post a comment.