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marti h

Air Bubbles In Clay

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I am unable to wedge clay due to arthritis in hands & wrists. Using a slab roller to remove bubbles from recycled clay takes forever. Any suggestions?

 

 

If you don't have acess to a pugmill that is suitable, you can try "wire wedging." There are instructions on the web about the technique. If you look up "Alabama potter" in YouTube, you'll come across a video of Jerry Brown throwing a jug, and he wire wedges his clay. Wire wedging is how I first learned to wedge, and I was a little surprised by the other techniques when I started taking classes recently.

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Well, my first solution is to recommend you stop recycling the clay and use new clay.

Store bought clay is cheap ... re-cycled clay is the most expensive you can use since you spend all your talented time on a non productive job.

It is also costing you in terms of prolonging your creative life and preserving your health.

 

Clay you get from a bag will not have air in it so slamming loosens it up enough to work with.

You slam wedge clay by throwing it down several times from different angles.

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Well, my first solution is to recommend you stop recycling the clay and use new clay.

Store bought clay is cheap ... re-cycled clay is the most expensive you can use since you spend all your talented time on a non productive job.

It is also costing you in terms of prolonging your creative life and preserving your health.

 

Clay you get from a bag will not have air in it so slamming loosens it up enough to work with.

You slam wedge clay by throwing it down several times from different angles.

 

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Good point on the cost, but my question is where do you dispose of 5 gallons of wasted clay every week or two?

 

I don't need nor do I have that many friends who need, mud packs???LOL

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I just discovered that some ceramic supply places rent out pug mills. You might want to give one a try to see if one may work for you.

 

Just today I've been looking at them online, wishing I had a little less self control with my credit card. One of those mixer/de-airing pug mills would be a godsend. The last supply place I went to had a notice board where people could put up for sale signs. Next time I go I'll be looking out for a used one.

 

That clay can be recycled is one of the great things about it. I don't see why we should be throwing it out.

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"That clay can be recycled is one of the great things about it. I don't see why we should be throwing it out."

 

Throwing it out in your yard is perfect recycling! The earth is exactly where it started.

 

 

I can only speak from a business angle .... If you want to put the time and energy and money into recycling a product that usually costs under thirty cents a pound, go for it. By the time you are through doing so your clay will be the most expensive raw material in your studio.

If you enjoy the process ... Great.

But consider that your time might be better spent making pots that bring in revenue rather than doing something that increases your costs.

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I'm with Chris on this one. Recycling takes time and physical effort. I have a Peter Pugger and use it when necessary, but for the most part use bagged de-aired clay that only needs to be slapped awake. If you don't want to put the botched batches into your yard, most schools (middle, high, and alternative) that have a ceramics program will welcome gift clay if it is in their firing range (usually cone 5). Or take the scraps and beat them into submission after the goo is gone and make stepping stones for your back yard. Don't bother glazing them--just fire to vitrification. Conserve your body's strength and put your effort into creating your art.

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There was a method in one of the pottery mags called "stack and slam", I believe. It was a form of wire wedging that involved cutting stacks of clay, slamming them on yer bench, and then repeating, resulting in a very thorough mixing. I will try to find it, in my back issues, I think it might have been in Studio Potter, or Pottery making Illustrated.

Anyway, I don't know how long it takes most people to reclaim, or what you make an hour potting, but I disagree on the cost of reclaiming clay.

I use three kinds of clay, and when I "lunch"(old dragracing term for blowing your engine) a pot, I drop it into one of three trays I have set aside for reclaim. It sits there and dries out while I MAKE OTHER THINGS. Time invested - 13.5 seconds.

After the clay is all bone dry, I break it up with a hammer. Time invested - 10 minutes.

After it is broken up, I fill each tray with water to slake overnight. Time Invested - 5 minutes.

The next day, I pour off the excess water and leave the clay to dry to wedging consistency. Time invested - 30 seconds.

The clay dries WHILE I MAKE OTHER THINGS, and it takes two - ten days in the summer. TIme invested - 0 minutes.

When the clay is dry, I wedge it up and bag it - Time invested - 30 minutes.

That represemts a total time investment of about 46 minutes, and I get about 50 pounds of clay doing this. Chris is right, the clay is about 30 cents/lb, so I have "saved" $15 of clay. That works out to about $20/hour that it costs me to reclaim clay.

Now, not to brag, but my wife and I make a good five figures making pots part time, and we, after figuring in all our time and costs, do not make anywhere NEAR $20 an hour. In fact, the way I work, I don't think I could ever make that much, and I doubt the average person on this forum does either.

Besides, every pound of clay that you throw out is another pound that has to be mined, processed, and transported, which all cost energy.

As far a pugmill is concerned, the cheapest mill I have found is about $2600 US. At $.30/lb for clay, that is about four and a half TONS of clay. That would last us about five years at least; so how worthwile is a pugmill, really?

Besides, a lot of the potters I see could use a little more of the "physical effort" involved in reclaiming.

Anyway, I will look for that article, and if/when I find it, I will try to post pics. for you, as I remember, it was a lot eassier on the hands/wrists.

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I am unable to wedge clay due to arthritis in hands & wrists. Using a slab roller to remove bubbles from recycled clay takes forever. Any suggestions?

 

 

If you don't have acess to a pugmill that is suitable, you can try "wire wedging." There are instructions on the web about the technique. If you look up "Alabama potter" in YouTube, you'll come across a video of Jerry Brown throwing a jug, and he wire wedges his clay. Wire wedging is how I first learned to wedge, and I was a little surprised by the other techniques when I started taking classes recently.

 

 

Thanks! I will check this out.

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Well, my first solution is to recommend you stop recycling the clay and use new clay.

Store bought clay is cheap ... re-cycled clay is the most expensive you can use since you spend all your talented time on a non productive job.

It is also costing you in terms of prolonging your creative life and preserving your health.

 

Clay you get from a bag will not have air in it so slamming loosens it up enough to work with.

You slam wedge clay by throwing it down several times from different angles.

 

 

Store-bought clay may be cheap for most people, but I live in the mountains & have to order clay AND HAVE IT SHIPPED! Thus, I need to recycle my clay. But, thanks for the reply.

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I just discovered that some ceramic supply places rent out pug mills. You might want to give one a try to see if one may work for you.

 

Just today I've been looking at them online, wishing I had a little less self control with my credit card. One of those mixer/de-airing pug mills would be a godsend. The last supply place I went to had a notice board where people could put up for sale signs. Next time I go I'll be looking out for a used one.

 

That clay can be recycled is one of the great things about it. I don't see why we should be throwing it out.

 

 

I agree. I can't stand the thought of throwing all that clay away!

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There was a method in one of the pottery mags called "stack and slam", I believe. It was a form of wire wedging that involved cutting stacks of clay, slamming them on yer bench, and then repeating, resulting in a very thorough mixing. I will try to find it, in my back issues, I think it might have been in Studio Potter, or Pottery making Illustrated.

Anyway, I don't know how long it takes most people to reclaim, or what you make an hour potting, but I disagree on the cost of reclaiming clay.

I use three kinds of clay, and when I "lunch"(old dragracing term for blowing your engine) a pot, I drop it into one of three trays I have set aside for reclaim. It sits there and dries out while I MAKE OTHER THINGS. Time invested - 13.5 seconds.

After the clay is all bone dry, I break it up with a hammer. Time invested - 10 minutes.

After it is broken up, I fill each tray with water to slake overnight. Time Invested - 5 minutes.

The next day, I pour off the excess water and leave the clay to dry to wedging consistency. Time invested - 30 seconds.

The clay dries WHILE I MAKE OTHER THINGS, and it takes two - ten days in the summer. TIme invested - 0 minutes.

When the clay is dry, I wedge it up and bag it - Time invested - 30 minutes.

That represemts a total time investment of about 46 minutes, and I get about 50 pounds of clay doing this. Chris is right, the clay is about 30 cents/lb, so I have "saved" $15 of clay. That works out to about $20/hour that it costs me to reclaim clay.

Now, not to brag, but my wife and I make a good five figures making pots part time, and we, after figuring in all our time and costs, do not make anywhere NEAR $20 an hour. In fact, the way I work, I don't think I could ever make that much, and I doubt the average person on this forum does either.

Besides, every pound of clay that you throw out is another pound that has to be mined, processed, and transported, which all cost energy.

As far a pugmill is concerned, the cheapest mill I have found is about $2600 US. At $.30/lb for clay, that is about four and a half TONS of clay. That would last us about five years at least; so how worthwile is a pugmill, really?

Besides, a lot of the potters I see could use a little more of the "physical effort" involved in reclaiming.

Anyway, I will look for that article, and if/when I find it, I will try to post pics. for you, as I remember, it was a lot eassier on the hands/wrists.

 

 

This sounds like a good plan but eventually takes us back to the wedging issue, doesn't it? Hope you can find that article! Thanks for taking the time to reply.

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Came across this...it may be the article you're looking for???? Hope this helps.

 

 

http://ceramicartsda...lay/?floater=99

 

 

Thank you for posting that article it has much better instructions for slam wedging than what I have been using, my slam wedging never came out bubble free. I used the bag clay for throwing then recycled it and used it with my slab roller and then any left over clay is wet down and saved for mold making. After using it for making molds I throw it away not wanting to worry about contamination. Denice (Wichita, KS)

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I am unable to wedge clay due to arthritis in hands & wrists. Using a slab roller to remove bubbles from recycled clay takes forever. Any suggestions?

 

 

 

I also have extreme arthritis, including plastic joints and steel pins and have thrown pots for the past 16 years with it. My first advice to you is to learn to use SOFT clay. By using clay that is wetter, you take an amazing amount of stress off of your joints. In addition, the clay is more homogeneous when wetter without hard spots. The premixed, bagged commercial clay is way too dry for me and it must be wedged before using because it has hardened bands of platelets caused by the extrusion process. They are slight, but very noticeable, especially on larger pieces.

 

The best clay for me is recycled slop. I mix it in 5 gal buckets with a mixing bit in my drill. Let it stand for days so all of the lumps become saturated and it is at the same consistency. This is easiest if you let all of your scrap dry out completely, then add water to it. If you don't have large plaster slabs made up, pour the slop out in a thin layer on a swept concrete driveway on a warm day. Depending on temp and humidity, it dries to a nice consistency in a few hours to a day. Check it often and then scrape up with a 5 inch paint scraper and place in bags or a bin. You will find this clay works perfectly for arthritic joints! It is far better and more even in moisture than any store bought clay.

 

Also, I hope you are not wedging to get "air bubbles" out of clay. These are only a problem in the throwing process where they cause a bump every time the wheel makes a revolution. I pop them with a needle tool. Air pockets will not cause any problems in the kiln, provided the work is absolutely bone dry. Don't ever throw out slop! It is pure gold and only takes a little of your time to recycle. Nobody should be so busy that they can not come to know intimately the substance we work with daily. I also dig my own clay and have gotten to know it intimately, as all professional potters should. Hope this helps! There is a way for you to create. Overcome obstacles by creative thinking and arthritis will never master you.

 

 

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I am unable to wedge clay due to arthritis in hands & wrists. Using a slab roller to remove bubbles from recycled clay takes forever. Any suggestions?

 

 

 

I also have extreme arthritis, including plastic joints and steel pins and have thrown pots for the past 16 years with it. My first advice to you is to learn to use SOFT clay. By using clay that is wetter, you take an amazing amount of stress off of your joints. In addition, the clay is more homogeneous when wetter without hard spots. The premixed, bagged commercial clay is way too dry for me and it must be wedged before using because it has hardened bands of platelets caused by the extrusion process. They are slight, but very noticeable, especially on larger pieces.

 

The best clay for me is recycled slop. I mix it in 5 gal buckets with a mixing bit in my drill. Let it stand for days so all of the lumps become saturated and it is at the same consistency. This is easiest if you let all of your scrap dry out completely, then add water to it. If you don't have large plaster slabs made up, pour the slop out in a thin layer on a swept concrete driveway on a warm day. Depending on temp and humidity, it dries to a nice consistency in a few hours to a day. Check it often and then scrape up with a 5 inch paint scraper and place in bags or a bin. You will find this clay works perfectly for arthritic joints! It is far better and more even in moisture than any store bought clay.

 

Also, I hope you are not wedging to get "air bubbles" out of clay. These are only a problem in the throwing process where they cause a bump every time the wheel makes a revolution. I pop them with a needle tool. Air pockets will not cause any problems in the kiln, provided the work is absolutely bone dry. Don't ever throw out slop! It is pure gold and only takes a little of your time to recycle. Nobody should be so busy that they can not come to know intimately the substance we work with daily. I also dig my own clay and have gotten to know it intimately, as all professional potters should. Hope this helps! There is a way for you to create. Overcome obstacles by creative thinking and arthritis will never master you.

 

 

 

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Yes, I have been wedging to get air bubbles out before hand-building. I have ALWAYS been told that air bubbles would "blow out" in the kiln. Are you saying that the bubbles disappear as the clay dries?

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I am unable to wedge clay due to arthritis in hands & wrists. Using a slab roller to remove bubbles from recycled clay takes forever. Any suggestions?

 

 

 

I also have extreme arthritis, including plastic joints and steel pins and have thrown pots for the past 16 years with it. My first advice to you is to learn to use SOFT clay. By using clay that is wetter, you take an amazing amount of stress off of your joints. In addition, the clay is more homogeneous when wetter without hard spots. The premixed, bagged commercial clay is way too dry for me and it must be wedged before using because it has hardened bands of platelets caused by the extrusion process. They are slight, but very noticeable, especially on larger pieces.

 

The best clay for me is recycled slop. I mix it in 5 gal buckets with a mixing bit in my drill. Let it stand for days so all of the lumps become saturated and it is at the same consistency. This is easiest if you let all of your scrap dry out completely, then add water to it. If you don't have large plaster slabs made up, pour the slop out in a thin layer on a swept concrete driveway on a warm day. Depending on temp and humidity, it dries to a nice consistency in a few hours to a day. Check it often and then scrape up with a 5 inch paint scraper and place in bags or a bin. You will find this clay works perfectly for arthritic joints! It is far better and more even in moisture than any store bought clay.

 

Also, I hope you are not wedging to get "air bubbles" out of clay. These are only a problem in the throwing process where they cause a bump every time the wheel makes a revolution. I pop them with a needle tool. Air pockets will not cause any problems in the kiln, provided the work is absolutely bone dry. Don't ever throw out slop! It is pure gold and only takes a little of your time to recycle. Nobody should be so busy that they can not come to know intimately the substance we work with daily. I also dig my own clay and have gotten to know it intimately, as all professional potters should. Hope this helps! There is a way for you to create. Overcome obstacles by creative thinking and arthritis will never master you.

 

 

 

 

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"Yes, I have been wedging to get air bubbles out before hand-building. I have ALWAYS been told that air bubbles would "blow out" in the kiln. Are you saying that the bubbles disappear as the clay dries? "

 

If you got six potters in a room you would get six opinions on this.

I believe the blow out problem comes from the clay not being dry rather than "air bubbles".

Touch the vessel to your check and if it feels at all cool, it is not dry.

Thick objects are hard to dry and often are deceptively dry looking.

Bubbles don't disappear but most clay is porous enough to let trapped air leak out during bisque.

 

.... Now for the other five opinions .... : > ) .... offered with a smile

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Guest JBaymore

You can fire totally enclosed forms.  It is water turning to steam in the small pockets that is the issue, not trapped air.  If pieces blow in this manner.... it still had physical water of formation in it.

 

best,

 

...................john

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My experience with bubbles in clay is limited but that said... I bought a new extruder and used the square hollow plate to make some little pencil boxes. The first batch I pulled had an issue where the clay rejoined as it extruded out. I smoothed the areas over and then set them aside to dry. I got paranoid a few days later thinking they would blow up in my kiln if I missed a single bubble. I was going to throw the whole lot out but decided to talk it over with my teacher and he suggested letting them dry for a longer time then firing them together in a group on a shelf just in case one of them did blow hopefully the pieces around it would stop any fragments from hitting my elements. I actually sat them aside for a couple weeks and then bisque fired them and had no issues what so ever with any of the dozen or so pieces blowing up. I fixed the extruder issue by sanding the inside corners of the plate.

 

I was terrified of air bubbles when I started working with clay but now like with the extruded boxes if I have any doubt about a piece being air bubble free I simple set the piece aside for an extended period. That doesn't mean I am not careful a wrongly placed air bubble can leave an unattractive mark on a flat surface. But I no longer worry about those mysterious hidden air bubbles waiting to burst out and destroy my work and kiln.

 

I also have wrist issues and have found wedging really soft clay to be the charm for me. I fill 2 gallon baggies full of clay scraps and water and throw it on the ground repeatedly until well mixed and then dump it out and wedge it.

 

I also want to try the cut and slap wedging method and have watched the video several times. Next time I wedge I am going to try it even though I don't have the strung wire frame. To just try it out it will be slower but I think using a regular wire to slice the clay will work just fine.

 

Terry

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