Jump to content
khaarhoff

Melted clay in glaze firing...

Recommended Posts

Hi everyone, 

I opened my kiln this morning after my glaze firing yesterday and found some pieces melted...they didn't explode, they didn't warp or bubble, they actually melted.  I'm so confused why this would happen.  I fired to cone 6 in my electric kiln and what's also curious is that other cups I slipcast with the same slip, and positioned next to a piece that melted, are intact and made it through like normal.   And one piece that melted was not a slipcast piece...it's so odd.  Any thoughts?  Has this happened to anyone else? 

Thanks!

IMG_6057.jpg

Share this post


Link to post
Share on other sites

Hi Khaarhoff,

Cool pieces! Curious, the melted were poured from same container of slip? Same glaze? Looks over fluxed for that temperature; did any of the other pieces slump a bit - show any signs of losing the battle with gravity? If other pieces were at all slumpy/drooping, my guess would the collapsed ones were in hot spots, else, different clay.

Share this post


Link to post
Share on other sites

That is an overfired clay!

Alternately, I've personally seen something like that happen, when a dried glaze powder was accidentally mixed in with wet clay, instead of a dried clay powder.  Both powders were the same color and consistency.  So nothing seemed amiss, until they were fired a couple projects, that used that clay.  They slumped pretty bad, but didn't completely  melt.  They also took on a hint of the glaze color.

So yeah, luckily that bad mix was just a couple student's mixed clay, and it just got tossed.  I felt TERRIBLE though, because one of the students had a nice sculpture, that she put a lot of work into.

Share this post


Link to post
Share on other sites

Thanks for your responses ~ they were poured from the same container of casting slip but I added some regular slip to fill up my molds in those 2 pieces...that must be the issue.  I added such a small amount I didn't think it would be so detrimental.  Yikes!  Well, lesson learned.  Nothing else was slumped or droopy.  Will never do that again!

 

Share this post


Link to post
Share on other sites
2 hours ago, khaarhoff said:

they were poured from the same container of casting slip but I added some regular slip to fill up my molds in those 2 pieces...that must be the issue.  I added such a small amount I didn't think it would be so detrimental.

Was the extra slip you added lowfire? 

 

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


×
×
  • Create New...

Important Information

By using this site, you agree to our Terms of Use.