A novice, making a novice mistake

[Frogspawn]

First of all, thank you for any information you may provide. 

Second, looking through some of the posts with pictures of your creations has been amazing! I bought an inexpensive wheel for my kids and I to learn on and we've been having a blast.

Now, on to the real reason for posting...

I bought some clay from Highwater Clay (Bellas Blend 04-6) and then picked up some glaze from Blick. I truly didn't understand the difference between 06 and 6 (I actually thought the zero was just optional). We glazed several items and, of course, mixed the different glazes on the items. After the first firing the 06 glazes came out glossy and the 6 glaze, no shock, came out very rough and matte. Can I re-fire them at cone 6? What will happen to the 06 glaze that is already glossy?

These are not for resale, nor use with food or liquid. They are simply for us to put on the shelf and admire as we, hopefully, get better.

Thank you all again for any input!

[Callie Beller Diesel]

Hi and welcome to the forum!

If you’ve combined them on the same piece, you could have some problems. Cone 6 is considerably hotter than cone 06, as you’ve realized. If you attempt to refire the piece which I assume has both 06 and 6 glazes on it, the cone 6 glaze will be glossy and mature. If you try and take the 06 glaze to cone 6 however, it could do any number of things, not many of them good. It could work out and create very interesting, if runny, effects. Or, it could run right off the pot, or it could blister like over-melted chocolate in addition to running off the pot. It depends on what glazes you’ve used. There are some things that have a stiffer melt and might not do this.

If you are using your own kiln, my suggestion is that you have nothing to loose at this point, and you should treat it as an experiment and a learning experience. Put the piece in a shallow, flat bottomed bowl or on a large clay saucer, and refire it to see what happens. You’ll gain some knowledge about your materials, which is useful information going forward. Be warned though: in doing this, there’s a good possibility of wrecking kiln shelves if you don’t have a large enough catch basin and the glaze isn’t contained properly. If you are renting kiln space from someone else, check and see if they’re willing to give it a go with proper precautions. Some won’t want to do it because of that potential for disaster, or they may not want to waste the kiln space on destroying a piece.

[Frogspawn]

Callie, thank you for the speedy reply! The studio that fires our clay told me about my oops but apparently no one has made that oops before so she was also unsure of the outcome. She said she is going to put one small item on a "cookie" and see what happens (all I could think about were cookies at that point). It's an item of mine, rather than the kids, so if it goes terribly wrong I wont lose one of their items. Although, if it doesn't end well on that one item I may just clear glaze (06 glaze) over the kids items so it's contained and not so rough looking.

On a sidenote.. you make some SERIOUSLY amazing things on your website. LOVE LOVE LOVE the swear word mugs! perfect mug for a Monday morning or when you wake up to a full inbox!

[Min]

Going forward if you are going to use this clay for functional pots like cups and bowls etc then I would fire to cone 6. From Highwater Clays page for this clay it has an absorption rate of 13% at cone 04 which means the pots will leak. When fired to cone 6 the absorption rate drops to 1.5%.

Orton cone chart below showing how they start at 022 as the coolest cone, the 0 preceeds the other number up to 01 then goes 1, 2, 3 etc up to 23. There is approx 400F difference between cone 06 and cone 6, makes a huge difference in both clay and glaze maturity.

[Frogspawn]

LRB, IFB, SSB, SSK, SRB, BRB... OMG!! So, I think what I'm supposed to take away from this chart is that the clay we are using should be fired at cone 6 for anything retaining a liquid or food. Am I close? I own an IT company so clay and glazes are a bit foreign.

[Callie Beller Diesel]

Don’t worry about the LRB, etc. That part’s for ordering the cones. 

Functional work can be made at earthenware temperatures, which is usually around cone 06-04. Or at any point above that, really. The big takeaway is to match your glaze’s maturing point to your clay’s maturing point. It’s important to remember that clays that say they have a wide maturation point (cone 6-10 is a common claim), really only are fully mature at the top end of the listed range. At the lower end, the clay is porous, and will absorb anything that sneaks under a crazed (crackled) glaze. 

[Frogspawn]

13 minutes ago, Min said:

From Highwater Clays page for this clay it has an absorption rate of 13% at cone 04 which means the pots will leak. When fired to cone 6 the absorption rate drops to 1.5%.

Regarding this.. is this implying that it is clay without glaze? If you do glaze an item (assuming it's at the proper cone) is it always "waterproof"?

[Frogspawn]

2 minutes ago, Callie Beller Diesel said:

It’s important to remember that clays that say they have a wide maturation point (cone 6-10 is a common claim), really only are fully mature at the top end of the listed range.

While calling around to studios in the area, many said they only do low temp firing because high temp stresses the kiln. The place I found, owned by a lovely lady, will fire at higher temp but things may wait a little longer until she has a full kiln of things waiting. So, for my clay claiming 04-6 is it ok to fire at 06 for the normal items sitting on a shelf but always aim for cone 6 on food safe items? 

[Callie Beller Diesel]

Absorption tests are done on clay without glaze, yes. Glazes do not always render a pot fully waterproof unless the glaze and clay “fit” each other perfectly, which is an infrequent occurrence, especially in people who are just learning, or aren’t too worried about making functional ware. It matters though, because glazes can develop a number of flaws, such as crazing, or pinholes, or other undesirable textures. There are often micro cracks in the glaze that liquids can seep into over time. If you have a pot that doesn’t have mature clay and a crazed glaze, the pot will weep. You can see how this could get icky if you leave half a cup of coffee with cream in it on the counter overnight.

As far as firing your work to cone 6 for functional items...yes, if you keep using that particular clay. If you find an earthenware and glazes that don’t craze on it, you can fire it to 06.

[Frogspawn]

2 minutes ago, Callie Beller Diesel said:

As far as firing your work to cone 6 for functional items...yes, if you keep using that particular clay. If you find an earthenware and glazes that don’t craze on it, you can fire it to 06.

Do you have any recommendations for clays and glazes for the amateur novice? I went with Highwater because they're down the road. I am open to any suggestions and like the idea of 06 so it can be fired more frequently. The kids were talking about making bowls, plates and cups in the future as well. 

[Callie Beller Diesel]

I’m in western Canada, so my recommendations aren’t readily available to you unfortunately. Check with whoever you’re firing with. They’ll have more local product knowledge than I will. Clay is heavy and therefore expensive to ship, so it tends to be a regional commodity. 

[Frogspawn]

2 minutes ago, Callie Beller Diesel said:

I’m in western Canada, so my recommendations aren’t readily available to you unfortunately. Check with whoever you’re firing with. They’ll have more local product knowledge than I will. Clay is heavy and therefore expensive to ship, so it tends to be a regional commodity. 

Do you recommend a specific type of clay for the newbie? We went with light grey colored because my daughter chose it. Is a type easier for the newb?

[Callie Beller Diesel]

When you’re starting out, there’s a learning curve on any clay body. Some will tell you to avoid porcelain to begin, but if you’re working at low fire, that’s not an issue because porcelain is mostly commercially available at cone 6 or cone 10.

If you’re working on the wheel, you don’t want a clay with a lot of grog (fired clay ground to sand) in it, because it’ll hurt hands. Beyond that, most earthenwares and stonewares are pretty forgiving. Think about the kind of work you’d like to make, and choose your materials to suit that.

[Frogspawn]

Thank you for all of the responses. I've reached out to the local university art department and they're going to get me a list of items they use for beginning students. 

A couple items I did this week are attached...

Thank you again!

[LeeU]

I use Bella's Blend and it is a lovely body, & easy to work with.  I strongly prefer firing it 5-6, not 05 etc. Talk to the Highwater people about what you are doing-they will help select a good body for your purpose & can help you with glaze choices.  For me, I find it best to "pick one" in terms of working in low fire or mid fire, especially when relying on other people's kilns & types of kiln loads. Personally I'd junk what is not working currently and begin again--it's almost never worth it to try and salvage work with problems as you've described.  And you will be teaching your kids that there is a value to learning proper methods and that discarding something that just isn't right is not only OK, it is a good thing to do.  Let you kids know there are technical reasons  for not making their plates/bowls/cups for low fire and they'll just need to be patient while they wait for the mid-fire. 

[Frogspawn]

18 minutes ago, LeeU said:

Personally I'd junk what is not working currently and begin again--it's almost never worth it to try and salvage work with problems as you've described. 

I think my goal is less "salvaging" and more keeping a reference for where we started. Having our first pieces to reference will be a testament to our bettering our skills. I can already see a difference in the process that the three of us were doing and are doing. 

Being in IT for 26 years has created this dependency for tech being around me, and my kids, all the time. The idea of taking earth and creating something brings me back to early civilization. Something so pure and innocent about it while also getting something to hold on to for memory.

[oldlady]

your pig is cute, when you make the next one, thin down the ears.   the thrown pot is excellent for a raw beginner.   it appears to be a clay with a lot of grog in it.   when you work with it does it feel sandy?  

anyway, i have been using highwater cone 6 Little Loafers clay.   it thows very well and and is excellent for hand building.  if you dry it out enough, you can use it for slab work.  it fires very white so the colors of glaze you use are more like the tests shown.   just a suggestion for a great clay that does not have grog but is easy to work with.

[Frogspawn]

8 hours ago, oldlady said:

your pig is cute, when you make the next one, thin down the ears.   the thrown pot is excellent for a raw beginner.   it appears to be a clay with a lot of grog in it.   when you work with it does it feel sandy?  

anyway, i have been using highwater cone 6 Little Loafers clay.   it thows very well and and is excellent for hand building.  if you dry it out enough, you can use it for slab work.  it fires very white so the colors of glaze you use are more like the tests shown.   just a suggestion for a great clay that does not have grog but is easy to work with.

Thanks for the compliment and suggestion! I think my goal on the pig (and plans for several more animals) was ridiculous dimensions. Kind of like a hot wheels but with animals. I'll try that clay the next time. It's nice having a clay place so close by. I also just realized you're close by me. I'm up in Palm Harbor.

[Hulk]

"...reference for where we started."

That resonates! I've a short "timeline" shelf of pieces, which includes first ever mug (other early pieces are scattered about the house and yard...), a current piece, and selections from in between.

On the tech side, I've an eight inch floppy disc tacked to the wall, heh.

[Frogspawn]

8 hours ago, Hulk said:

On the tech side, I've an eight inch floppy disc tacked to the wall, heh.

LOL!!!  Love that! I've been looking for an antique typewriter so I can date even my 27 years in IT. 

Thanks for the chuckle.