Jump to content


Photo

cracks and pinholes in glaze application


  • Please log in to reply
5 replies to this topic

#1 deHues

deHues

    Member

  • Members
  • PipPip
  • 26 posts

Posted 19 April 2012 - 10:57 PM

In my class in college, the instructor said that the application of the glaze should not be so thick that it pin holes or cracks. Today I applied glaze on a lot of pots and some of the glazes seemed too thick, but being a bit thick myself, I did not add water to them. There were pin holes and cracks in the glaze applications.

When they were dry I rubbed with my fingernail to fill in the cracks and pin holes. I guess I could wait the week and a half to answer this question myself, but being an impatient potter, I am so anxious to know it I have messed it all up or if everything is just fine.

The glazes were cone 10, matte yellow, tenmoku, ohata, oribe, moonlight, oatmeal and a few others.

What do you think? Thanks.

#2 Mark C.

Mark C.

    Advanced Member

  • Members
  • PipPipPip
  • 2,746 posts
  • LocationNear Arcata Ca-redwood rain forest

Posted 20 April 2012 - 01:53 AM

In my class in college, the instructor said that the application of the glaze should not be so thick that it pin holes or cracks. Today I applied glaze on a lot of pots and some of the glazes seemed too thick, but being a bit thick myself, I did not add water to them. There were pin holes and cracks in the glaze applications.

When they were dry I rubbed with my fingernail to fill in the cracks and pin holes. I guess I could wait the week and a half to answer this question myself, but being an impatient potter, I am so anxious to know it I have messed it all up or if everything is just fine.

The glazes were cone 10, matte yellow, tenmoku, ohata, oribe, moonlight, oatmeal and a few others.

What do you think? Thanks.


I think if its really thick a few of those glazes will look like dry cracked lake beds-some of the matts may like a bit thicker application
Those high iron glazes will be darker and can run real thick-oribe is one that needs to be just right with thickness.
One thing is you will learn from this straight away. Nothing like mistakes to learn faster. If you want you can wash all the glaze off with water-let pot dry one day and reglaze with same thinner glaze.Thats what I do when i drop a pot into bucket as a mistake.
I assume this is all on stone ware clay??
Mark
Mark Cortright
www.liscomhillpottery.com

#3 Pres

Pres

    Retired Art Teacher

  • Moderators
  • 1,991 posts
  • LocationCentral, PA

Posted 20 April 2012 - 07:58 AM

In my class in college, the instructor said that the application of the glaze should not be so thick that it pin holes or cracks. Today I applied glaze on a lot of pots and some of the glazes seemed too thick, but being a bit thick myself, I did not add water to them. There were pin holes and cracks in the glaze applications.

When they were dry I rubbed with my fingernail to fill in the cracks and pin holes. I guess I could wait the week and a half to answer this question myself, but being an impatient potter, I am so anxious to know it I have messed it all up or if everything is just fine.

The glazes were cone 10, matte yellow, tenmoku, ohata, oribe, moonlight, oatmeal and a few others.

What do you think? Thanks.


Did you wash the pottery before hand with a damp sponge? This usually will cut the absorption rate of the glaze and even out the application with a thinner coat than a dry pot. As Mark said you may wash the pot completely and re-glaze. I realize that these pieces are your "babies" so if you have the time-re glaze.

Simply retired teacher, not dead, living the dream. on and on and. . . . on. . . .                                                                                 http://picworkspottery.blogspot.com/


#4 neilestrick

neilestrick

    Neil Estrick

  • Members
  • PipPipPip
  • 2,524 posts
  • LocationGrayslake, IL

Posted 20 April 2012 - 10:34 AM

The issue is not the cracks or pinholes- rubbing them out won't matter. They are simply indicators that the glaze has been applied too thickly. The real issue is that the glazes will likely run, and possibly end up on the kiln shelf. The thicker the glaze, the more it runs (generally). Wash them off, let them dry completely, and try it again.
Neil Estrick
Kiln Repair Tech
L&L Distributor
Owner, Neil Estrick Gallery, LLC
www.neilestrickgallery.com

neil@neilestrickgallery.com

#5 deHues

deHues

    Member

  • Members
  • PipPip
  • 26 posts

Posted 20 April 2012 - 03:00 PM

Thank you for your helpful answers. Yes they are all stoneware and I did sponge them off first. When I get back to school on Monday they won't have been fired yet so I am going to heed your advise and wash them all off. Especially since on the lips I had the inside glaze layered over the outside glaze and then I had little dips of a third glaze and I also used a slip trailer bulb to decorate lightly with another glaze towards the top.

Fortunately the crit is on Wednesday and they wouldn't be out of the kiln by then anyway. We are able to use greenware or bisque in the crits since there is such a huge number of pots that are assigned. I think the instructor wants to make sure that students don't view this as a goof-off class, so he really puts the pressure on. But I notice he grades very kindly if you're doing lots of work.

I now need to use this experience to learn how thick the glaze in the bucket should be. Using the finger dip method. Thanks.

#6 Marcia Selsor

Marcia Selsor

    Professor Emerita, Montana State University-Billings

  • Members
  • PipPipPip
  • 3,838 posts
  • Locationwhere Texas, Matamoros, Rio Grande and Gulf of Mexico come together.

Posted 20 April 2012 - 03:28 PM

I make my students wash off the thickly applied glazes so they won't run onto the shelves. They are suppose to check the glaze consistency before glazing. Add water if needed. My test is to stir the glaze, then stick a dry finger in the glaze and check the knuckle. One should see lines of the knuckle. It is an old-fashion method but it works.
I have demonstrated this in class.
My recommendation is to wash off the thick glaze. Let the pot dry a day or so and then reglaze it.

Marcia




0 user(s) are reading this topic

0 members, 0 guests, 0 anonymous users