[Clayart] Underglaze issue

Eleanora Eden via Clayart clayart at lists.clayartworld.com
Wed Apr 29 14:35:58 EDT 2015


Hi Alice,

You don't mention what type of underglaze this is.  There are those  
with frits and those without.
  If you are able to apply directly under the glaze without problems  
perhaps this is one with frit.
Thus it could cause vitrification problems like the thread discusses  
if applied to raw ware.

Best,

Eleanora





On Apr 28, 2015, at 8:47 AM, Alice DeLisle via Clayart wrote:

> I think that the most direct solution might be to bisque twice, once  
> before and once after applying the UG.  I could experiment with  
> applying the UG to leather hard clay, but that could be a long and  
> complicated experiment.  This popping doesn’t happen with every pot,  
> every time, more like 1 in 4 or 5, so it could be difficult to  
> interpret the results.
>
> Thanks to all who have added to this discussion.  You have been most  
> helpful.
>
> Alice
>
>> On Apr 27, 2015, at 7:03 PM, via Clayart <clayart at lists.clayartworld.com 
>> > wrote:
>>
>> my interpretation of that is that the underglaze makes such a tight  
>> barrier on the surface that water can't pass through it without  
>> popping off the surface of the clay. Similar to the way terra  
>> sigillata can behave. Maybe you really do have to pre-bisque to use  
>> these underglazes. Or bisque really slowly and make sure the pots  
>> are really dry before they go in.
>>
>> Sumi
>>> The bit that pops off actually takes some of the underlying clay  
>>> with it.  That is why the pot can be ruined.  If it were just the  
>>> UG coming off, I could put some more on to fix it.  The UG around  
>>> the pop is well-adhered.
>>>
>>> Alice
>>>
>>>> On Apr 25, 2015, at 8:00 AM, via Clayart <clayart at lists.clayartworld.com 
>>>>  <mailto:clayart at lists.clayartworld.com>> wrote:
>>>>
>>>> From: Snail Scott via Clayart <clayart at lists.clayartworld.com <mailto:clayart at lists.clayartworld.com 
>>>> > <mailto:clayart at lists.clayartworld.com <mailto:clayart at lists.clayartworld.com 
>>>> >>>
>>>> Subject: Re: [Clayart] Underglaze issue
>>>> Date: April 24, 2015 at 2:23:14 PM EDT
>>>> To: Clayart international pottery discussion forum <clayart at lists.clayartworld.com 
>>>>  <mailto:clayart at lists.clayartworld.com><mailto:clayart at lists.clayartworld.com 
>>>>  <mailto:clayart at lists.clayartworld.com>>>
>>>> Reply-To: Snail Scott <claywork at flying-snail.com <mailto:claywork at flying-snail.com 
>>>> > <mailto:claywork at flying-snail.com <mailto:claywork at flying-snail.com 
>>>> >>>, Clayart international pottery discussion forum <clayart at lists.clayartworld.com 
>>>>  <mailto:clayart at lists.clayartworld.com> <mailto:clayart at lists.clayartworld.com 
>>>>  <mailto:clayart at lists.clayartworld.com>>>
>>>>
>>>>
>>>>
>>>> On Apr 24, 2015, at 7:27 AM, Alice DeLisle via Clayart wrote:
>>>>> ... have been having a problem...with small bits of the UG  
>>>>> popping off in the bisque firing...
>>>>
>>>> If you pick at the bare peeled spots, do the edges of the engobe  
>>>> seem
>>>> well bonded to the clay, or just held in place by their adhesion  
>>>> to the
>>>> rest of the surrounding coating?
>>>>
>>>>                                  -Snail
>
> MAILMAN_MIMEDEFANG WRAP
> _______________________________________________
> Clayart mailing list
> Clayart at lists.clayartworld.com
> http://lists.clayartworld.com/cgi-bin/mailman/listinfo/clayart
>
> MAILMAN_MIMEDEFANG





More information about the Clayart mailing list