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diymom

Pin Holes In Brushed On Glazes-What Does It Mean?

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I am loading my kiln for my second ever glaze firing to ^6, I used amaco pc brush on glazes on my bee mix forms bisqued to ^04. I see lots of little pin holes and I am very worried that it means I'll have pin holes in the glazed piece. Why did my glaze do that as I brushed it on? My bee mix has grog, would that effect it? I have a ceramics book which I am finding very useless as it literally breezes over glaze technique and goes into depth on glaze ingredients...it says something about dusting off or something when it describes one of the 5 or 6 ways you get pin holes or bubbles in glaze...in one paragraph. The book doesn't go into more detail as to what it means. Do I need to sand down the glaze to fill the holes or something?

Help, I am worried and I need to start the firing today!

 

Oh and I used some pc glazes over some aardvark dip glazes on a few tiles and a few colors are peeling off the dip glaze....why?

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lightly rub your fingers over the places you see holes.  the powder that will result is glaze. you are just redistributing it.  DO NOT BLOW ON IT as that will spread it around the room and you might breathe it in.  

 

i have not tried layering glazes because that is what happened the time i tried it.  not my thing.

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lightly rub your fingers over the places you see holes.  the powder that will result is glaze. you are just redistributing it.  DO NOT BLOW ON IT as that will spread it around the room and you might breathe it in.  

 

i have not tried layering glazes because that is what happened the time i tried it.  not my thing.

Everything in there is layered! I love the effects of layering amoco's pc glazes...well, theoretically...I've just seen pictures. I am so nervous I could sit in there the whole firing and fret. Thank goodness I'm too busy to do that. I rubbed in all the holes and wiped off the wax resist and spaced everything about 1/2". I think I should have put my test tiles on the top shelves where it's probably hotter. I have witness cones all over. My load is a little light, I wish there were more pieces in there for a full capacity load.

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I had something similar going on when I would dip glaze my work down at the community studio. I was told that it's a natural thing and not to worry about it, as the glaze would compensate by flowing during the firing process. They must be right as I could never find hide nor hair of a single one of those little pin holes when the piece came out of the kiln.

 

If it's any consolation, diymom, I know exactly how you feel. I fret over every load, regardless of whether it's a bisque or a glaze firing.

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I've had the same thing in a studio I was working at with the same kind of glazes. As you usually paint several layers (3 usually), I tried to really suqeeze the glaze in the tiny holes when I was doing the second and third layers by pressing harder with the brush. It was not always perfect but after the firing, it always looked just fine. I think that when the glaze melts, it evens itself out.

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Yes, I was using freshly made glazes for dipping, they are totally frustrating to mix evenly...clumps and bubbles!

Kiln is up to 2056 degrees, I am impatiently checking it too often and practically pacing. I want mugs now! It will take all night/day to cool down. It took 12 hours + for my bisque firing to cool. I am going to wait until I have morale support to open it tomorrow. I need sleep.

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No I didn't dampen them, I had 3 different clay bodies, the srgf (I think that's the abbreviation), black mountain and bee mix with grog. The first really sucked in the glaze, the second, weirdly did not and acted like it was vitreous and the third, the bee mix did great. I am a little surprised at the variation. Kiln is cooling down, I went with medium speed to ^6 and it took over 10 hours. It has cooled down to 1000 degrees since it completed. I think I'll have to wait until tonight at least to see inside. Still so worried. Hope nothing bad happened in there. Tonight will either be a great night or a very disappointing, dismal one.

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After 25 hours of natural cooling! Oh my goodness, I was dying to see inside,so frustrating! I opened the kiln at 140 and I was pleasantly not in horror as I had planned. But the amaco pc glazes must be something of an art since I had many pieces which weren't coated enough and others appeared to be travelling too far down the mug...like my cone 6 firing was too much for the glazes. Most everything was fine, a few really nice pieces, a few major duds...all my black mountain or whatever bloated and discolored...maybe come 5 is the max for that clay... but I'm not depressed with failure nor am I chipping all my glaze off shelves. I have my favorite piece ever out of this load...it's so dainty and perfect, I don't want to use it for its intended purpose...

Anyway....only a few pinholes, not in the places I expected except on one surf terracotta type clay. Will make better mugs and try more dipping glazes.

Thanks for the input and encouragement and commiserating with my woes!

Learning pretty fast now.

High Bridge Pottery likes this

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Brushing on glazes is an art, and requires several steps to insure decent glazing. 1) always wash your pots with a damp sponge to remove any amounts of dust, and to put a bit of moisture in to help the glazes flow on evenly. 2) when brushing, flow your glazes on. In other words do not brush a lot with the brush, but put the brush in the glaze, stroke a bit on to the pot and always keep the brush wet with glaze by dipping often. 3) put further coats on immediately after sheen is gone from first. 4) Three brushed coats=1 dipped coat. 5) When layering put next layer on immediately after the first layer. Do not do all pieces in first glaze, then the second.

 

These worked for me for years while still glazing. Too time consuming so I started dipping and am much happier. Good luck on your next glaze set.

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I have used their brush on but not the dipping glazes- I have heard they are very, very different ... there is a face book page called Potters Choice Exchange... They have a couple people on there that work at Amaco and may have some helpful tips for you...

 

Which colors did you use?

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Brushing on glazes is an art, and requires several steps to insure decent glazing. 1) always wash your pots with a damp sponge to remove any amounts of dust, and to put a bit of moisture in to help the glazes flow on evenly. 2) when brushing, flow your glazes on. In other words do not brush a lot with the brush, but put the brush in the glaze, stroke a bit on to the pot and always keep the brush wet with glaze by dipping often. 3) put further coats on immediately after sheen is gone from first. 4) Three brushed coats=1 dipped coat. 5) When layering put next layer on immediately after the first layer. Do not do all pieces in first glaze, then the second.

 

These worked for me for years while still glazing. Too time consuming so I started dipping and am much happier. Good luck on your next glaze set.

I have used their brush on but not the dipping glazes- I have heard they are very, very different ... there is a face book page called Potters Choice Exchange... They have a couple people on there that work at Amaco and may have some helpful tips for you...

 

Which colors did you use?

Brushing on the glazes was extremely time consuming!!!! I followed their two coats per glaze for their layering glaze directions...should have done three of one coat. There are a ton of areas where I can see thin glaze, blotchy glaze,brush strokes even though I swear I put on the second coat perpendicular to the first direction. However, it was all late at night when I did these. I have noticed more pin holes on several pieces. I didn't know about wetting the pieces first. Amaco also says they let the first coat dry completely before subsequent applications. I also had some very thin pieces that take forever to glaze and dry enough for another coat. I can't spend hours glazing things 5 times! I think I'll phase these glazes out and revert to dipping which works so well for me.

 

I have on more issue....these pieces I've made are making high pitch cracking noises even now, three days later. My husband drank hot tea out of his new mug and it was making cracking noises the whole time! That's awful! Did I do something wrong????

 

I used true Celadon, very lustre, both turquoises, arctic blue, light sepia, frosted melon, Smokey merlot, and iron luster. Smokey merlot costs more and has the best dependability, light sepia comes next. I didn't have a fan brush, just a thick Japanese square brush. It seemed to work alright.

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Did the glaze separate and leave a brown spot? I know that the artic blue does it...

 

Smokey Merlot is  great base coat...Great glaze...Iron Luster over it looks fantastic by the way..

True Celadon is dependable as well...

Verte Lustre is good, I havnt had any problems with it..

 

the others could crawl on you.. The best way to fix all of your Blues is to add 1 tea spoon of Amaco Gum per pint... They have readjusted the binding mixture but are waiting for approval ... Should be on the shelves by summer but for now add the gum...

 

 

As far as your wares pinging , the glaze is not a good fit for your clay body... What you are hearing is the glaze cracking... what % does your clay shrink? sounds like the glaze is to big..

 

We wash our bisque in a sink of water with a big sponge, then sit it front of a fan over night.. Then glaze...

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you folks work so hard to use commercial glazes!   making your own glazes is not rocket science.  i just cannot see any advantage to spending so much money for the glaze in a tiny bottle, spending so much time brushing it on, spending so much time worrying about it, spending so much money firing it and so much time moaning about the results.  where is the fun part?

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Saving money for my dry ingredients rite now... not rocket science but there is still a lot of things needed to be safe and the room to keep it as well... I already have a few materials..

 I don't mind brushing glazes on myself, I kind of like it... slows me down so I can get a good amount of time with the piece in my hand... I notice more...

 

I get good results with Amaco/Coyote/Mayco/Ky. Mudworks glazes, the main thing as with any glaze is to TEST it first... If you have problems call them..  

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I'll have to talk to the people at my local clay supplies store about a clay with less shrinkage...seriously, it's my first time working with clay in over 8 years and I appear to have made children's mugs and a few shot glass mugs that were supposed to be children's mugs. I never used this clay body in the past and it really does shrink! I guess I have to order some clay from amaco until my glazes are gone. Has anyone tried these e over a tan clay body?

Some of the glazes did crawl on me, the turquoise and blues left bare spots around the rim, particularly the layering combos of textured turquoise.

My intention is to eventually make my own glazes, but I wanted some bright, sexy colors for my saleable pieces. I don't want a ton of browns and darker greens, reds, blues etc. I think I'll try another manufacturer next and stick with dipping.

 

I did some test tiles with a dipped glaze that was tan under some amaco glazes and they preformed very well with no crazing. They retained their intended colors very well too. I will be using those to stabilize these glazes

 

I don't feel like I should sell these mugs if they are crazing. Especially if they are making cracking noises when they are used for hot liquids. What if they are microwaved???? I definitely wouldn't get good feedback. Now I won't make any money off all that work. Looks like they'll be "gifts with explanations".

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diymom, you can get very nice colors with glazes you make yourself.  every recipe is a base glaze.  even if it has a color in the name like Rutile Green.

 

once you have a number of stain colors, just make the base recipe and separate a bit of it to try other colors in it.  i talked about this on the forum a long time ago.  it is too much typing to repeat it, just think tiny amounts to test for color.  100 grams gives a huge amount to test.  10 grams can be used for several colors.

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I will look into making glazes next year, I have to make some $ to pay for my supplies right now using what I've already got. Ideally I want to get production costs down once I develop my market, that's when making glazes will come in handy I presume.

Right now I am making some molds for my signature mug series I have developed. When those sell and begin to get commissioned in quantity, I'll customize some glazes.

Is there a glaze recipe book? Are they mostly measured by weight?

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since you have a year, you will have time to check out what your local library can get for you.  there are M A N Y glaze recipe books.  most have good recipes listed by firing temperature.  your own records should include more than just temperature and color, there have been several recent discussions here on setting up a glaze kitchen and how to record things.

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I was firing my bisque to 06 changed to 04 and I hardly ever have a pinhole. I use a lot of amaco PC and a few others in that line. love the mixing to get the look I want. I have layered on Albany slip and acai and it is beautiful almost looks like a wood fired glaze.  I have a skutt electric. cone 10 is what I fire, I use amaco #38.  I have been looking at some cone 5-6 clay but just haven't made the change yet as I have just mixed up a 4 gallon bucket of yellow salt blue that our teacher came up with at ULM. it is really nice in reduction it will have a soft matt finish with brown flecks and streaks of light blue where thicker but mor soft off white with the darker flecks. but at oxidation it is has a light blue with a little more sheen all over it.still lovely but I like the reduction look the best. the school has a huge beast of a gas kiln. 

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