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flowerdry

Covering Greenware After Attachments

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So, yesterday I felt like a kid who was told that Santa doesn't exist.

I was taught that if I make any attachments such as a handle, I need to cover the piece for a while...like overnight...for the moisture levels to equilibrate.  I thought this was one of those absolutes in clay.

Turns out it's not so, as long as the piece doesn't dry too fast and attachments are made at the right stage of dryness.

 

Who out there covers and who doesn't?  Have any of you had experiences where you didn't cover and it didn't work out well?

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The pieces are covered and placed in a covered drying rack. I always cover after attaching, it is a logical step for me. Sometimes I may leave the piece covered for 3 days. Especially those pieces with multiple attachments, like teapots. Never tried without covering. Too much time invested in the piece to take a chance it will crack. At the least, the piece will be covered for 1 day, such as mugs. I like to use the plastic covers you get from the dry cleaners they use to protect your clothes. 

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In most cases for me, the different parts have very different moisture levels. e.g. the mug handles are soaking floppy wet, while the mug bodies are leather-hard. My attachment points will crack if I don't allow the parts to equalize first.

 

But I also think what you say is true, if the parts are at a compatible moisture level with each other, covering is not always necessary.

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in places with very high humidity, pieces do not need much covering even if there are attachments.  a plastic grocery bag dropped over a piece should be enough.  i cut the handles off a lot of bags at once and store them in one of those cloth holders with openings at the top and bottom.  filling the bag with air and letting it just touch the shelf (drywall) allows even drying. 

 

when making a lot of bowls i cover everything once i have put slip on the pot and before carving.  then i have a number of them held at the same degree of dryness and can spend time carving for an hour or so, the fun part, 

 

of course, i work differently from many people.  i use Duron (thick masonite) bats and do not wire off anything.  pots pop off Duron on their own.  i trim very close to finish thickness while throwing them so they can pop off without splitting.

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This is another "It all depends ..." question.

Some clays are so forgiving you can do just about anything to them ... Others punish every moisture imbalance.

Some climates are more forgiving ... others so dry the moisture immediately gets sucked out too quickly.

One mug drying by itself is much different than a closely packed ware board of 30 mugs.

Some potters have the experience to judge all factors just right so when things are attached they are all even and it sure looks easy.

That said, if you have put a ton of work into something, slowing the drying makes good sense ... Why save time only to lose the pot?

Chilly, florence w and Darcy Kane like this

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This is not a fixed answer-it all depends.Many factors to consider -many have covered them in above posts.Things that will affect this are what types of clay-humidity factors-moisture content.

We usually cover our handled forms for 1 night.Our clay is porcelain.We have found this reduces cracking best. the size of forms and handles are also taken into account with this.

That said today we will not. After handling about 50 mugs they will be dried in the sun and then heat dried in warm shop all night then bisqued in am.

sometimes I will lose one doing this forced drying .Last week it worked great.

Mark

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When I worked in a basement in Southern Illinois, I had to wait 4 days just to trim. Im Montana, it was about an hour. Humidity is the key there. As for handles it depends. Lately for some porcelain I don't always pull them from the body. I actually form them and let them set up quite a bit before attaching. They don't shrink as much.I am getting less, if any problems. And I do lightly cover for a day or so.

 

 

Marcia

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In my classroom, I generally have students partially cover pieces, when they have recently attached something.  With that said, if it's earlier in the term, we play it safe and cover things.  However, if it's the last day to work with wet clay, no cover, and it gets put on a vent to try!  

 

The clay body is usually forgiving enough, that we can get away with it.  Usually the only issue, is when students try to attach wet clay, to dry leatherhard clay... or even bone dry...  I tell them this won't work, but what do I know?

LeeU likes this

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So, yesterday I felt like a kid who was told that Santa doesn't exist.

I was taught that if I make any attachments such as a handle, I need to cover the piece for a while...like overnight...for the moisture levels to equilibrate.  I thought this was one of those absolutes in clay.

Turns out it's not so, as long as the piece doesn't dry too fast and attachments are made at the right stage of dryness.

 

Who out there covers and who doesn't?  Have any of you had experiences where you didn't cover and it didn't work out well?

You mean Santa doesn't exit? Who brought my train set?!!!? :o:wacko:

flowerdry and Amy Eberhardt like this

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I always cover with plastic sheets. You gotta. At the Archie Bray, as a resident, I didn't cover my 10 teapots with attached pulled handles. They all cracked. It didn't rain there all summer. They don't even have rain gutters on their houses.We call them eavestroughs.

TJR.

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TJR now that you realize santa was a hoax please pack up and mail me that old train system -my address is at my web site.Thanks I will take good care of it-sorry about your red suit dilemma .

 

Getting back to covering handled forms these mugs made today as weel as two other bat fulls of soup mugs where pushed dry today. They where thrown today then handled  today and put into the 70 degree day of sunshine. Tonight they are on top shelves in studio with gas heater roaring (about 95 degrees up there) I will load and fire them in bisque in early am tomorrow . Glaze them on Friday with full kiln load of pots as I have done now for 5 fridays in a row. I'm pushing for a big show in Arizona next weekend

March27-28-29th

The mugs are crack free at this point as all the connections where made during the perfect time for joining.I usually cover them 1 night but if you get it right you do not have to. Also Porcelain dries real fast and this works in your favor if you time it right.This will take some time to learn if you are new at this so experiment and see what can be done with clay as far as pushing the limits. Until you find them you do not know where they are.

One can also load the damp mugs into a hot just unloaded glaze kiln and with no burner on they dry right out saw well. If I had a hot kiln unloaded today that would be my 1st choice to dry them. But as I;m firing them fast in am I want them bone dry hence the hot shop which is drying some other forms tonight as well.Today its was 40 regular 1# mugs and 16 soup mugs pushed dry with handles no cover and no cracks.

Mark

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post-8914-0-10679500-1426738131_thumb.jpg

Chris Campbell likes this

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After attaching handles i cover the work with an old bed sheet or pillow case. I have found the cloth lets everything dry more evenly. With plastic sometimes I would get unwanted condensation.   When possible I store mugs and similar handled pieces upside down. If the newly attached handle is a little soft, the upside down gravity helps prevent any drooping or pulling away from the body. Covering newly attached work is a good guideline.  Like any other "clay rule", sometimes you can break the rule and get lucky. Following "clay rules" just improves your chances of success.

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well, after saying that my clay doesn't need covering in the high humidity here, i have to wonder if the raku clay i threw for two days will act a little like little loafers in drying.  it is now 2:30 in the afternoon and i am about to get dressed and go out to the studio to see if the bottomless 6 inch high 12 inch wide form i did last evening, 9 pm or so, can be shaped into a flower brick and take some texture.  woke up at 6 am, dizzy and sick, went back to bed and just woke up.  talk about letting it be!

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well, after saying that my clay doesn't need covering in the high humidity here, i have to wonder if the raku clay i threw for two days will act a little like little loafers in drying.  it is now 2:30 in the afternoon and i am about to get dressed and go out to the studio to see if the bottomless 6 inch high 12 inch wide form i did last evening, 9 pm or so, can be shaped into a flower brick and take some texture.  woke up at 6 am, dizzy and sick, went back to bed and just woke up.  talk about letting it be!

Migraine? or flue?

Mark

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something i ate did not like me.  (usually it is living beings who don't like me.)  anyway, the clay was fine, it was only a matter of running a wet-ish sponge around the inside and the outside of the main form, rolling out a slab for the bottom and one for the top.  construction was finished at 7 pm after several trips inside to rest and recuperate.  this is a new form for me and so i did take pictures so i could see if there is a better way.  a little dampening at each step made it work just fine.  attachments should stay firmly in place, now to trim the folded over edges.

 

yes, it is covered and equalizing the dampness so i hope there will be no cracks tomorrow.

 

for someone who does these forms........... i added a grid on the interior floor so stems that run through the holes above have a place to stand against and not flop over.  is this the usual way to do this?  there are circular holes in the top, shrinkage will make them about 3/4 inch holes.

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Holy moly, I am a baaaaad guinea. :D

 

I pretty much NEVER cover my work after attaching handles, bahaha! :D I guess eastern Washington has a magic level of humidity that keeps my handles okay. I guess I'm tempting the fates a bit, heehee...

 

Bad Guinea!

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As so many folks have said here. . . knowing your clay and circumstances makes a difference. I was taught in a previous century, that when adding handles you needed to cover them with plastic so that they would not dry faster than the pot. Others told me that recently additions to pieces needed to be covered to allow slow drying.

 

Over the years though, I have found that PA has a variety of weather that has to be watched closely. If I am trimming pieces and it is raining out, I make a point to join the handles and leave everything uncovered. If it has been dry, and warm weather, I cover.  I really prefer to add handles when it is raining, than dry.

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