Hope someone can help me! Shivering problems! My business is at stake

[Dottie]

I've been working with lowfire white earthenware for over two decades with no problems.  Recently, however, I've begun having a shivering problem.  I use only commercial products in my work, so I'm not very versed at all in anything other than simple chemical changes in materials.  I've been making wall sculptures for most of the last 20-plus years, using molds that I make and adding hand-built features onto them so that each piece is different.  Everything went perfectly well until recently, and I cannot figure out what has changed.  It appears that almost 100% of the shivering that is occurring is on the hand-built parts of the pieces.  (I'm using the same clay I've always used for both the slip and the wet clay parts of my work.

Recently, I have  received what is for me a large commission:  11 large animal sculptures.  I've built most of them already and have painted (amaco underglazes) and glaze-fired (low-fire clear glaze off the shelf) and glaze-fired the first two.  They both have places of shivering, usually on smaller projections on the pieces.  

Since I've always made everything the same way, I cannot figure out what has changed. My process:  After I hand-build a piece, I bisque fire it to cone 04.  Then I do all my artwork on it with the amaco  velvet underglazes.  Then I glaze each piece, and then I glaze fire to cone 05.  And, again, until recently, every single thing came out perfectly.

I'm so desperate I can't sleep, so any suggestions at all would be more than welcome.  Time is running out on my sculptures commission, so that adds to my anxiety. 

[Dottie]

I need to add that I also would like to know if I might possibly save the two already finished pieces.  The shivering is in small areas, so has anyone had any success at all in perhaps sanding down the areas, reapplying underglaze and glaze and refiring?

 

[Min]

Is this a new lot of clay, batch number different? Is it the underglaze that's shivering off? I'm not sure that I would try and fix the pieces that have shivered. Sometimes shivering doesn't happen straightaway. I'ld try taking something dense like a screwdriver and gently tapping edges and protrusions and see if any more bits shiver off. For sure it's shivering and not crawling? 

[JohnnyK]

Some photos of the problem would help a lot in determining what the problem might be...

[Callie Beller Diesel]

Can you describe what kind of clay you use for your hand built additions? Is it slip that you’ve dried out, the same clay body but without the deflocculant or a separate clay altogether? Are you buying premixed slip, or are you buying it dry and adding water and deflocculant?

[Sorcery]

How's the elements?

Sorce

[Dottie]

Sorry; I wrote this request and then was tied up the rest of the day, so I have a lot to answer.

First, Min:  Yes, it's definitely shivering.  And, yes, I've got some pieces that are weeks old and sitting on a hard surface.  Even after a couple of weeks, there are flakes popping off.  And I can, yes, flick off pieces that look suspicious.  And it is the underglaze that is shivering, going right down to the bisqued clay.  I hadn't thought of the clay as a problem, and I had just recently bought new clay from the same source as always, premixed, wet, and in bags.  But one reason I can't imagine that that's my problem is that this seems to occur almost (not 100%) always on my sculptures, both large and small.  And I've been building my large (between 1 and 2 feet tall) sculptures for quite a few years without problem.  I use the same wet clay on my small, molded for the most part, wall-hanging pieces, and for a short while this year, I had a minor problem with them, which I attributed to my having put too much water in my commercially prepared but too thick glaze.  In fact, I completely replaced my glaze and thought my problem was solved -- until I did some more sculptures.

Johnny K:  Yes, I'll be adding some photos of pieces that don't have the problem and some others of pieces that do have the problem.  

Callie:  I use slip only for the "body" of my smaller pieces and add bagged clay as "appendages (see photos).  There is no slip at all used on the sculptures.  So that can't be part of the problem, I think.

Sorcery:  That's something I was  going to try next.  I have two kilns, a smaller one and a, to me, huge one.  I almost always use the smaller one, and it is quite old and well-worn.  I have never replaced an element in it.  I'm currently working to get enough pieces done to fire the big kiln, so I'll be checking that soon.

Here are some more ideas I have, although, again, I've been doing everything the same way for, well, forever it seems:  I've always used the same materials (wet bagged  white low-fire (06-1) clay from my clay supplier (for the past five years Seattle Pottery, before that Georgie's in Portland, OR), Amaco velvet underglazes for the most part, occasionally another manufacturer's underglaze, and pre-mixed transparent colorless low-fire glaze (I think made by Seattle Pottery, but I'm not positive on that).  I have always bisque-fired to 04, then painted onto the pieces, then glazed and fired to cone 05.  In the past, I always cheated on getting things out of the kiln early, like really hot sometimes, because I had a show to get to.  These days, I'm being very patient, even adding a soak period (30 min) to the end of my glaze fire and waiting until the kiln is hand-cool to open it.  I have always fast-fired (kiln's presets) both glaze and bisque (with nary a problem until now), but I've tried firing slowly now, with the soak and without, and no effect at all.

So what's left to investigate?  I don't have a clue -- except, of course, the possibility that I have some element issues with my small kiln.  Again, not to belabor the point, but this has happened very, very suddenly, within the past few months.  The rooster on the left

I'm adding photos, which is difficult for me because I always feel that all of you are gods and I'm some lowly person who happens to make something that sells well, so please forgive me up front for my lack of mastery in clay.   So I guess I can brag that people find my pieces humorous and, especially now, by golly we need humorous!  (The rooster, on the left, is entirely hand-built, with a thrown base, all same clay, and it has shivering problems.  The dog's face  only is from a mold I made, and the ears, tongue, nose, ball, and tongue are built from the wet clay and attached/added.

And thanks to all of you who are trying to help me solve this problem.  Thank you, thank you, so much!

 

[Dottie]

Oh, I don't have a photo of the shivering problems on the rooster, but they're on the tail in this instance, mostly at "edges," places that are either outside edges or just where the plane in the shape changes.

[Min]

1 hour ago, Dottie said:

I hadn't thought of the clay as a problem, and I had just recently bought new clay from the same source as always, premixed, wet, and in bags.

If this is the only variable I would be contacting the manufacturer and asking if ANYTHING has changed. Their supply of talc or whatever they are using for flux, the ball clay or kaolin. Give them the batch number from the box so they can look into it.

1 hour ago, Dottie said:

I'm adding photos, which is difficult for me because I always feel that all of you are gods and I'm some lowly person who happens to make something that sells well, so please forgive me up front for my lack of mastery in clay. 

This is just plain silly! Your work is delightful!

[Stephen]

do you have any of the old clay in a recycle bin to run some test with?

[Mark C.]

Low fire bodies that shiver could be from a change in clay ingredients as mentioned. My thought is its a talc body with a change. You say the body is all the same no changes-get the box Numberrs and call the supplier as Min suggested. See what changes have occurred . Nothing in ceramics stays the same for long including clays-meaning whats in them. I think the firing is a red herring-the clay and glaze is what it usually is. I had a low fire potter go thru this 25 years ago and it put him out of business. Its turned out it was a change in the clay and that was a talc change. I would think about a clay body change-testing will be key

 

[Dottie]

Okay.  I am furious!!!!!  It is the clay!  I just contacted Seattle Pottery Company, my supplier, and they gave me the wrong clay the last time I was in there.  They gave me paper clay instead of my regular clay.  I have been working on an 11-piece commission of large full-body dog sculptures, 8 of which are completely built and ready to fire, one of which is in progress.  They are due by November 1 and take days and days and days to get built.    

I was asked by them why I didn't notice the difference in texture, which thinking back, I did, and I figured it was because my old purchases were so very old that they had hardened a lot.  I even remember thinking, wow,  I had no idea how hard my old clay was (I buy in very large quantities when I go there because it's a couple of hours away, so I buy about a year's worth at a time.)  I noticed that the labels on the outside of the boxes were a different color, but they said "LF06, so I  they had just changed labels as they had recently changed ownership.  Nowhere did the label say "paper clay."   By the way, as with all clay suppliers, I place my order inside, and it is put into my car by one of their people, as at any clay supplier, so I never saw the boxes until I got to my studio.

Anyway, I'm now waiting to hear from the manager.  The assistant manager said I could drive over there with the wrong clay and exchange it.  I said, I don't think so.  I'm asking them to replace the clay and deliver it to me.  But I presume there's absolutely nothing I can do about all the blankety-blank work I've already done on my sculptures.    Now I'm going to have to work myself to the bone to get all these sculptures rebuilt and out the door in time for a November 1 deadline.

Oh, and one more thing:  At first, they denied that it could be my clay and said that I ought to contact Amaco instead.   

Sorry this is so long.  I just had to vent!   And thank you alllllllll for your help in solving this most vexing problem I've ever faced in my rather long career.  

[Min]

Perhaps contacting the shop/gallery and explaining your situation, not making an excuse, would be worth doing. Gallery owners should know that handmade work can have setbacks, extend the deadline if possible. Show them an image with the issue, they will see you have been working on the order and want to supply the pieces, but not ones with defects. If the paperclay you were sold is the same base as your normal clay I would still confirm nothing has changed with it. It must be very frustrating and heartbreaking, I'm sorry you went through this.

[Babs]

Paper clay may be more absorbent after the bisque ?? If so maybe thin with water the underglaze before application , worth a try if @Min thinks this would be the case for already made beauty.

[Dottie]

Ok.  Things are worse, even.   Seattle Pottery Company (and, yes, I'm loudly saying who they are) called me back and said that I need to show a receipt of my last two purchases.  I'm so sorry, but other clay supply companies I've worked with over the years have always, always had itemized copies of receipts (such as Georgies in Portland, OR, with whom I worked for well over a decade).  Anyway, for that reason, I've not bothered to keep itemized receipts once I checked in my purchases from it.  I only have my payment receipts.  Well, it turns out that Seattle Pottery doesn't keep itemized receipts, ever!  They say that if I don't have my itemized receipts, that they will not refund  or even exchange the clay THEY erroneously put into my car.  I have spent thousands of dollars with these people over the past five years that I've lived close enough to them to call them my supplier.  So I'm out the money for the clay, out for all the sculptures I've already made, and out for all the other things I've made that I now can't sell, even if they haven't begun shivering.  

However, I do have a little plan:  I think I'm going to try one of two things:  First, I might try just painting underglazes on one of  the sculptures and see if I can just sell it retail to a customer unglazed.  I was really tired of everything's being so shiny, anyway, so maybe it could be a different route for me.  Second, if that doesn't work, I'm going to do something I know will work:  I am also a painter (on canvases), and I have tons of acrylic paints because I under-paint in acrylics and final paint  with oils.  So I'm going to paint some bisqued ones with acrylic paints and perhaps find a good acrylic spray that will fix the paint so it won't wear off.  

As my mother used to say,  "If life gives you lemons, make lemonade!"

And I'm off to Spokane, WA, the other direction from my home to a clay supply company there, and I've already verified that they have exactly what I need!  I am a wiser person now.

Again, thanks for all your help and support.

[Dottie]

Babs, I'm not quite sure I understand what you're saying.  Are you suggesting that if I thin my underglazes and apply them,  and then I presume glaze and fire, that that might solve the problem?   

 

[GEP]

@Dottie, I agree with @Min. Call the customer, explain what happened, and ask for some more time. When I was doing a lot of wholesale work, customers were always understanding when I really needed some more time. Especially if you have a history of making deadlines (which it sounds like you do). 

I’m sorry this happened to you. I would switch suppliers too. 

[Dottie]

Oh, and Min, yes, the rep at Seattle Pottery said that the earthenware that I have used for the last five years is indeed still the same.  But as I've stated above, they won't honor an exchange if I don't have the receipt.  Seattle is over two hours away from me, so I can't see driving that far (it takes up almost a whole day with the traffic around there) just to get a couple hundred dollars of clay, which is what my last purchase was.  But they're really losing a lot in the long run because I've bought kilns, a slab roller, all my materials from them for the last five years and had intended to do so for the next however many years I continue to do this work.

[Dottie]

Thanks GEP and Min.  First of all, I'm a bit of a workaholic, so I'm going to see how much I can get done in the next week.  I have managed to learn a few shortcuts while I've been building these that were finished so far (each one is very different, though, but still the main principles are in each one).  So wish me luck!  If it appears that I'm not far enough along in two weeks, I'll contact them and explain my situation.  Gallery owners can be a bit difficult sometimes, so I want to do my best to get them done in time.  Plus, they're just the middle man; the pieces are for one of their customers who is going to present them as awards and whatever their big function is.

 

[Babs]

39 minutes ago, Dottie said:

Babs, I'm not quite sure I understand what you're saying.  Are you suggesting that if I thin my underglazes and apply them,  and then I presume glaze and fire, that that might solve the problem?   

 

Well my thought process is if your stuff only shivers on the paper clay, perhaps it is more porous after bisque...paper burns out right? So spaced out clay particles.

So those parts absorbing more underglaze material,  some of my underglazes stuffs up when too thick.

If you have ware already made, may be worth trying thinner application on the paper clay areas

Or just a bit of paper clay trial piece...

A Bit with no glaze but underglaze thinned and one with both layers. 

Just saying

Could sand off the offendfing shivering areas and paint.car patch up..metallic????

[Dottie]

Babs.  Hi, I am in the process of trying to sand off and repaint the pieces with just small areas that have shivering.  Don't know if it works, though.  I'll let you know what I find out.  But I really, really hope someone doesn't end up with such as mess as this is.  I just realized, in fact, that I have tons of bisqued but not painted or glazed pieces that I've built up, and I don't know which ones are bad and which ones are okay.  This really explains, too, why some pieces have come out just fine and others are unusable.  Oh, what a mess!

 

[Dottie]

Oh, Babs.  I finally get what you were saying!  Yes, I'll give that a try!  Thanks so much.

[Babs]

If occurring just around edges you may be inadvertently applying  u.glaze more thickly because of your brush action?

Glaze may be taken up thicker on the p.clay areas too

Paper clay may make different ping after bisque when flicked???  To help identify which bisqued stuff  ....has additions of p.clay

[Dottie]

Hi, Babs.  I thought of that possibility and adjusted for it.  It made no difference.  And I was dipping into glaze and began brushing, too, to cover the glaze question, too.

I'll try the bisque sound suggestion to see if I can tell a "flick" sound difference and let you know what I learn.

[Bill Kielb]

6 hours ago, Dottie said:

So I'm going to paint some bisqued ones with acrylic paints and perhaps find a good acrylic spray that will fix the paint so it won't wear off.  

As my mother used to say,  "If life gives you lemons, make lemonade!"

I really like this idea and if acrylic finish is fine for the client, It is predictable and gets you temporarily closer to your commitment. There are many acrylic or urethane very durable clear finishes satin and gloss which you might enjoy.