For just about any question in ceramics there are two good basic answers. 

  1. "It depends."
  2. "Try it!"

How to glaze ware for single firing is one of those questions that seem to lack cut and dried answers. Simon Leach glazes his pots by dipping and pouring in a short time frame on pots about leather hard.

Steven Hill pours interiors and sprays the exteriors and layers without a lot of concern for time between coats, but he starts with near bone dry pots.

The timing and techniques are going to be very dependent on the clay body, the glaze composition and viscosity, and the method of application to name a few variables.

A number of authorities insist that a single fire glaze have a high clay content to allow it to shrink like the clay body it is applied to.

Please use this forum to exchange info on how you glaze your work for single firing.

 

This forum is in response to a Kathy Ransom query

Comment by Kathy Ransom 4/13/2011

I just watched the Simon Leach video about using wax resists and didn't realize he does single firing.  He dipped a bowl, then poured glaze into it and said that both inside and outside need to be done at the same time. Revelation!! I've been carefully brushing my glaze on and letting it dry before carefully brushing more on, thinking that this would keep the piece from absorbing too much moisture.  I've had a few pieces just come apart though as they dried.  Is his method a solution to this and has anyone else tried dipping and pouring in one go and had success doing it this way?

Views: 728

Replies to This Discussion

Over in the Main discussion area is a similar topic "Raw Glaze Problem Solving".

I bought my critter sprayer and actually found it locally at Lee Valley Tool.  After a little experimenting, I love it and thanks to everyone for their suggestions!!  It is perfect for me as my hands don't get so tired and sore plus I handbuild rather slowly due to Muscular Dystrophy so equipment for keeping up with high production is not an issue.  I've also discovered that my work is a great deal safer if I spray my glaze on bone dry greenware until I achieve the thickness I need, then use a heat gun to dry the piece quickly.  I have a convection oven and when I have more work than I want to use the heat gun on, I turn the oven on convection at 300F and let the pieces dry in there.  I've managed to single fire a number of pieces this way with 100% success so far.  As my kiln is very small at about 2.5 cu ft and it uses up 2 days each time I fire, single firing is perfect for me and I'm very encouraged to do a lot more.  My main difficulty now is with getting just the right thickness of glaze as I love glazes with funky, cool effects that require a pretty heavy application such as Hare's Fur, Teadust, flashes of fluorescence in texture, etc.

 

I've also discovered that if I need to refire something which I do quite often, I can spray a light coat of glaze then dry it with my heat gun.  I can then spray a fairly thick coat which will stick really well to the now hot piece, dry it again when I'm finished spraying with the heat gun and can safely move it if I put a plastic bag over it.  I also add 2% of the dry glaze weight of CMC Gum to the water  I use to hydrate the glaze  as it makes the glaze easier to spray and helps to harden the sprayed glaze.  Between the gum and handling the sprayed piece with  plastic between it and my hands I have had great success.  

Just joined so am replying "late"  - I am interested in advice regarding application, too.  I ordered some Ravenscrag slip - and made up a clear for porcelain, that worked well over Cone 6 "Frost" - a golden rather than ice tinge. but I am thinking it will be interesting to test on a few pieces of stoneware for single firing.  Any advice? I am a dipper rather than a brusher.

By the way, Happy New Year, all!

It's kind of unpredictable.  Especially with commercial clays where you don't know the makeup. If your glaze has 20-30% clay in it you can try dipping leather hard and see if it stays adhered.  Glazes with less clay may need to be put on bone dry clay which may react by cracking or bloating, or be perfectly fine. I think its best to glaze bone dry ware quickly or let it dry for several hours between coats. I had good luck with Laguna #80 which is a medium brown stoneware.  It seemed to tolerate dipping very well.

Thanks, George, I will give it a try - my local supplier doesn't carry that particular Laguna clay but she will add a box to an order (I won't be buying lots) - I like a darker body in general.  I noticed the shrinkage is about 14%, so I can use that as a guide.  I am going to throw some bowls and cylinders in the bodies I do use (Highwater's's Speckled Brownstone, Earthen Red and Standard's Chocolate Brown #266). My interest is kind of a romantic one (harking back to the single firing days) as well as ecological and tactile - I like the feel of leather hard, dislike the feel of bisque, so more towards leather hard dipping, but some of my favorite glazes have a lower clay content than 20%.  I guess I just have to jump off the diving board. I don't have a lot of time in my studio, and while I love to experiment, I would rather not have to reinvent the wheel, jealous as I am of my time and energy.  I am intrigued by the idea of using dipping tongs and the actual marks they may leave o leather hard clay, as well as the challenge of designs that give one natural dipping finger holds. Of course bone dry dipping might not work with tongs ;-)  - and if I can get my hands on some Laguna #80, would try the bone dry route. Heck, I'll try bone and leather on all of them.  Thanks for your quick reply.

RSS

Videos

  • Add Videos
  • View All

Use These Links to Support Us

Low cost flat lapping disc can be used on you potters wheel if you, drill bat pin holes in it, and provide a trickle of water to cool it. At amazon.com, 120 grit for aggressive material removal. Click the image to purchase 

Members have had great things to say about John Britt's new book, Mid-Range Glazes. Click the image to buy from Amazon.com

Purchase Glazes Cone 6 by Michael Bailey, The Potters Book of Glaze Recipes by Emmanuel Cooper, or Making Marks by Robin Hopper, all available at amazon.comMastering Cone 6 Glazes by John Hesselberth & Ron Roy is now out of print.

Harbor Freight is a great place to find unbeatable prices for better HVLP spray guns with stainless steel parts and serviceable economy models, as well as detail guns, all tested by our members for spraying glazes, as well as compressors to power the guns. As yet no one has tested and commented on the remarkably inexpensive air brushes at harbor freight.

The critter siphon gun is a spray alternative that is well liked by some of our members, and is available at amazon.

Amazon is also a competitive source for photo light tents for shooting professional quality pictures of your work. They also have the EZ Cube brand favored by several of our members. You might also want to purchase the book Photographing Arts, Crafts and Collectibles . . .

If you are up to creating videos of your work or techniques you might want to invest in a flip video camera

Following are a few scales useful for potters. Ohaus Triple Pro Mechanical Triple Beam Balance, 2610g x 0.1g, with Tare $169.00

And finally a low cost clone of the OHaus. The Adam Equipment TBB2610T Triple Beam Mechanical Balance With Tare Beam $99.62

ebay is a great alternative for many tools and the equipment used in the ceramics studio - kilns, wheels, extruders, slab rollers are often listed there both new and used.

Tips for Members

If you just want to spout off, it is best accomplished as a blog posting. If you want to get more guidance and ideas from other members, ask a question as a new discussion topic. In the upper right corner of the lists for both types of posting, you will find an "+Add " button. Clicking it will open an editor where you create your posting. 4/16/2014

© 2022   Created by Andrea Wolf.   Powered by

Badges  |  Report an Issue  |  Terms of Service