Jump to content


Photo

Glaze Is Grainy, Rough At Lip Of Mugs

I want smooth soft lips

  • Please log in to reply
31 replies to this topic

#1 smokin pots

smokin pots

    Advanced Member

  • Members
  • PipPipPip
  • 124 posts

Posted 12 July 2013 - 09:37 AM

My stoneware mugs seem to be having major issues with their lips. Instead of the glaze breaking smooth over the lip it is rough and grainy just at the edges.

Im not sure if this is a throwing flaw from the chamois taking away too much clay leaving the lip rough or a glazing issue where the glaze breaks.

Either way, I must fix it because its not acceptable. Lips appear smooth after throwing, and I sponge  my 04 bisque before glazing. Firing to cone 6.

Hope someone has an answer!

juli

Attached Files


la paloma texas pottery

#2 Chris Campbell

Chris Campbell

    clay stained since 1988

  • Members
  • PipPipPip
  • 2,214 posts
  • LocationRaleigh, NC

Posted 12 July 2013 - 09:46 AM

Does this happen with all your glazes or just one? Also, what glaze is it? What's the name of the clay body you are using?

Chris Campbell
Contemporary Fine Colored Porcelain
http://www.ccpottery.com/

https://www.facebook...88317932?ref=hl

TRY ...   FAIL ...  LEARN ...  REPEAT


#3 mregecko

mregecko

    Potteries

  • Members
  • PipPipPip
  • 154 posts
  • LocationBay Area, CA

Posted 12 July 2013 - 10:06 AM

Looks to me like the glaze is just running down/away from the rim of the mug. The natural unglazed stoneware is rougher than the glossy glaze, so when it pulls away you get the groggy texture of the stoneware.

 

I'd say put more glaze on the rim of your piece. Are you brushing this on? I always have problems with thin rims while brushing because they get wetter and less glazes adheres. Maybe an extra brushing just on the lip once the rest of the glaze is dry.

 

If you're dipping, it'll be hard to do without creating an obvious line, maybe use your finger to put some extra glaze on the lip.



#4 OffCenter

OffCenter

    Advanced Member

  • Members
  • PipPipPip
  • 1,372 posts

Posted 12 July 2013 - 10:10 AM

I think it is the glaze. The glaze you're using on the pictured mug has to move a lot to acheive the hare's fur look so it is running off high thin places. That's not clay that is making the lip rought but spots of glaze. Try other glazes. If you have, did you have the same problem with them?

 

Jim


E pur si muove.

"But it does move," said Galileo under his breath.

#5 Marcia Selsor

Marcia Selsor

    Professor Emerita, Montana State University-Billings

  • Members
  • PipPipPip
  • 3,988 posts
  • Locationwhere Texas, Matamoros, Rio Grande and Gulf of Mexico come together.

Posted 12 July 2013 - 10:36 AM

It could be too hot for that glaze as Jim described above.
Add a different glaze on the rim and refire.

Marcia

#6 jrgpots

jrgpots

    The hands can express the soul

  • Members
  • PipPipPip
  • 514 posts
  • LocationHurricane, Utah

Posted 12 July 2013 - 10:40 AM

Try brushing on a glaze along the rim. Pick a glaze that does not run.

#7 smokin pots

smokin pots

    Advanced Member

  • Members
  • PipPipPip
  • 124 posts

Posted 12 July 2013 - 11:39 AM

Attached File  IMG_2735.jpg   173.24KB   1 downloadsWell, yes, it does happen with all three clays I use,,Trinity 6,and two Armadillo clays, a brown and a white.
The glazes are nutmeg, (pretty stable)l, and butterscotch over rutile blue(pretty runny). Now that Ive said it happen with all my clays, and glazes, It might be my throwing.
la paloma texas pottery

#8 neilestrick

neilestrick

    Neil Estrick

  • Members
  • PipPipPip
  • 2,731 posts
  • LocationGrayslake, IL

Posted 12 July 2013 - 12:09 PM

Make sure the lip is rounded, with no sharp edges. Use a chamois to round it, rather than your sponge. The sponge will wipe away the fine particles and expose the large rough particles. The chamois will give you a smooth, rounded edge that will hold glaze well.


Neil Estrick
Kiln Repair Tech
L&L Distributor
Owner, Neil Estrick Gallery, LLC
www.neilestrickgallery.com

neil@neilestrickgallery.com

#9 smokin pots

smokin pots

    Advanced Member

  • Members
  • PipPipPip
  • 124 posts

Posted 12 July 2013 - 12:42 PM

Just threw a mug and left the lip alone, much better looking. I love a chubby lip, and I think I overwork the lip trying for a nice curve and chamois it to death bringing to much grog to the surface. Bad habits are hard to break, and this one ive been doing for ever.
Ouch, I wish it was the glaze.
Thanks everyone for taking the time to give input!!!!
juli
la paloma texas pottery

#10 Pres

Pres

    Retired Art Teacher

  • Moderators
  • 2,067 posts
  • LocationCentral, PA

Posted 12 July 2013 - 02:01 PM

Overworking the clay at the rim yes, but I don't think the use of the chamois is a problem. Using a chamois usually smoothes the slippery smaller particles over the courser ones at the same time compressing the clay . . . albeit a small amount.


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


#11 Mark C.

Mark C.

    Advanced Member

  • Members
  • PipPipPip
  • 2,932 posts
  • LocationNear Arcata Ca-redwood rain forest

Posted 12 July 2013 - 03:32 PM

Pres summed it up -If you use a chaois holding it with two fingers it should compress the lip. 

You could also douple dip the lips a tad so more glaze stays there in the fire.

Mark


Mark Cortright
www.liscomhillpottery.com

#12 Benzine

Benzine

    Socratic Potter

  • Members
  • PipPipPip
  • 1,640 posts
  • LocationThe Hawkeye State

Posted 12 July 2013 - 03:37 PM

You know, I've never used a chamois to smooth the rim.  I have always used a flexible elephant ear sponge, or even just a standard cellulose sponge.

I may have to start with the chamois.


"Anything worth believing, is worth questioning"

#13 Nancy S.

Nancy S.

    My day job pays for my clay habit

  • Members
  • PipPipPip
  • 168 posts
  • LocationHarrisburg area, PA

Posted 12 July 2013 - 07:42 PM

You can also try using a very soft rubber rib, like the red ones from Sherrill, to do a final smooth-over on the rim.

 

Or, after bisque firing, use a stilt stone to grind down any rough areas...though this is tedious and makes a rather annoying noise...



#14 Pres

Pres

    Retired Art Teacher

  • Moderators
  • 2,067 posts
  • LocationCentral, PA

Posted 12 July 2013 - 09:01 PM

When I was teaching, I showed the kids the poorman's chamois-a small piece of folded over paper towel taken out the the garbage can. This works just about as well as a chamois, and is really cheap. However,  it can be a pain if it ends up in the slop. I have had times where I would be wire cutting clay and pull a piece of this through the clay, but then it happens with chamois too doesn't it.


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


#15 atanzey

atanzey

    -

  • Members
  • PipPipPip
  • 147 posts
  • LocationSouth-Central Pennsylvania

Posted 13 July 2013 - 07:31 AM

My chamois all have a small fishing bobber attached with a short fishing line. I think I got that idea on here! But after finding one in my slurry bowel, I got serious about implementation.

Alice

#16 Marcia Selsor

Marcia Selsor

    Professor Emerita, Montana State University-Billings

  • Members
  • PipPipPip
  • 3,988 posts
  • Locationwhere Texas, Matamoros, Rio Grande and Gulf of Mexico come together.

Posted 13 July 2013 - 07:41 AM

I use a chamois. I have a friend who used the web between her index and middle fingers. Using a sponge if wet, can wash away the clay and bring up the grog. Not the surface you want on a lip. Just put a thick matter glaze one the lip and refire.

 

Marcia



#17 Pres

Pres

    Retired Art Teacher

  • Moderators
  • 2,067 posts
  • LocationCentral, PA

Posted 13 July 2013 - 09:45 AM

My chamois all have a small fishing bobber attached with a short fishing line. I think I got that idea on here! But after finding one in my slurry bowel, I got serious about implementation.

Alice

Sorry folks , but I really have to say something as I am rolling in laughter here. Isn't it intersting how the insertion of an "e" can change the whole meaninng of a post. :lol:


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


#18 atanzey

atanzey

    -

  • Members
  • PipPipPip
  • 147 posts
  • LocationSouth-Central Pennsylvania

Posted 13 July 2013 - 09:49 AM

---- And I gotta tell you, that's an 'e' that I add on a consistent basis! But THANKS for pointing it out! My spelling and typing both leave a lot to be desired!

Alice

#19 Benzine

Benzine

    Socratic Potter

  • Members
  • PipPipPip
  • 1,640 posts
  • LocationThe Hawkeye State

Posted 13 July 2013 - 10:25 AM

What's funny is, how many people read the post, and didn't even notice that, including myself.  The brain does a great job, of changing things, due to context. 

It's like those sentences, where they purposely leave out letters/ words, or add them in, and you don't notice, because your brain does the editing.


"Anything worth believing, is worth questioning"

#20 Pres

Pres

    Retired Art Teacher

  • Moderators
  • 2,067 posts
  • LocationCentral, PA

Posted 13 July 2013 - 10:56 AM

Alice, please don't take offense. Even a spell checker would not have helped there. I was just having an internal brain giggle trying to tie the statement to some sort of cartoon.


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





0 user(s) are reading this topic

0 members, 0 guests, 0 anonymous users