Coleman Porcelain "not Recyclable"?

[spike39]

I thought I would try some Coleman Porcelain from my local supplier. The clerk said it was a great clay body but "you can't recycle it... something to do with its ingredients". She gave me no other instructions or guidance. Anybody else hear of this or can give me info? TIA

[neilestrick]

Interesting. I have never heard that. It could be that there's something soluble in there that gets washed out during the throwing process, or it's just a sales gimmick.

[Marcia Selsor]

I recycle it. sometime from throwong slop on my wedging table and other times from dried trimmings into slip and onto plaster. Gee, I wish I knew!

Marcia

[spike39]

Thank you Marcia..

 

I asked others in my guild and they seem to have the same reaction. "Huh?.. who knew?".

 

To be fair, when we recycle, everything gets thrown together.. stoneware.. porcelain in a large drum and then our claymaker puts it through a complete re-mixing, etc.

 

Maybe the clerk was saying that one couldn't recycle it as its own clay body back to an original "Coleman Porcelain".

 

Anybody else have input?

[bciskepottery]

Depending on how wet or dry you throw, you tend to lose the fine particles of clay in your slop.  When recycling, you need to restore those fine particles or the clay becomes stiff/hard to throw -- potters use the term short to describe the clay.  By adding your slop to the recycled clay (see Marcia's post), you restore fine particles and the clay keeps more of its plasticity.  If you don't add back your slop, you need to add a fine clay to the recycle clay. 

 

Given Coleman is a bit pricey, save your slop and recycle your own . . . don't mix it with the others.

[Marcia Selsor]

I recycle everything

1. because it is pricey 

2. the source is very far away.

I recycle the Coleman and use it for throwing to hand building smaller work. I do throw dry and tend not to get much slop or trimming scrap. I trim the bottom right after throwing and wedge that back into workable porcelain. Then later I trim the foot but not a whole lot left to trim off.

 

I am now in a place with a supply shop! But they don't have Coleman. I am bringing what I have left in Brownsville to Montana about 300 pounds. I tried Babu porcelain. I had a hard time throwing thin with it but when assembling  teapots, it was very forgiving. I guess they all have their virtue.

[glazenerd]

Mix 1/4 cup of EPK, 1/8 cup silica, and 1/8 cup Nep SY or Minspar.  Use this as an additive to the throwing slop to replace the fines lost in throwing. I know the Coleman recipe: this will work just fine. EPK is SAS 28.56: the finest of all the kaolin. Use 325 mesh silica in this case; and the same mesh size for the feldspar of choice. The idea is to replace the fines.

 

Nerd

[Marcia Selsor]

Thanks , Nerd.

Good to know this.

Marcia.

[glazenerd]

Slop tip #2

 

Add one tablespoon of bentonite to the additive above to help maintain the plasticity of the body.

If you are working with clay scrapes from a body, and you want more plasticity: then add 1/8 cup OM4 to increase plasticity in the recycled clay.

 

EX: 1/4 cup EPK  1/8 cup 325 minspar or Nep Sy, 1/8 cup 325 silica, and 1/8 cup OM4 ball clay.  Clay does not require the molecular balance glaze does: so "perfect" unity is not required.

 

Nerd

 

Marcia: if you want to duplicate Coleman exactly: the use grolleg.

             if you want to duplicate Southern Ice exactly: then use NZ kaolin.

[oldlady]

dearest nerd,

i have several very ancient boxes of coleman cone 10 porcelain.   since i cannot fire it, it sits under the wheel.   there is a new clay studio where i would be able to fire it.   if i decide to use it, i will use the "put the bag of clay into a bucket of water to cover it.  wait a day or so and it will soften" method for the new stuff.

i do have scraps and see your suggestion above.   however, there is no quantity given for the amount of "slops".  could you please add that?

thank you.

[glazenerd]

Dearest Oldlady:

coleman porcelain actually originated from experimental bodies used at Alfred. This article covers clay recycling, and Coleman in perticular.  Premium cone 10 porcelain is 50% grolleg porcelain, 25% silica, 25% Nep Sy, and 2% Macaloid. (BentoneMA) instructions are in the article

https://ceramicartsnetwork.org/ceramics-monthly/ceramic-supplies/ceramic-raw-materials/techno-file-clay-restoration/

[oldlady]

oh, for heaven's sake!   this reads like a sneaky way to advertise your latest contribution to Ceramics Monthly magazine.   i am embarrassed.  (and that is hard to do!)

[glazenerd]

Sneaky? I thought is was rather overt myself.   Besides, it is viewership round up month.

premium porcelain is 50% grolleg, 25% silica, and 25% Nep Sy. + 2% macaloid (Bentone ma) this is the fix it mix. If you do not have grolleg, then use EPK. EPK will diminish translucency a bit- your call.

how much fix it mix you add is directly proportional to the amount of water you use throwing, which equates to how much fines you lose. So you have to make that judgment. For a gallon full of dried reclaim 1/8-1/4 cup of fix it mix will work. 

 

Most of the members post pictures of their work in the gallery. I am limited where I can post mine.

 

[MFP]

Does that actually work? Mixing everything together like that?  How do you use it?  I am very curious.....I am in the process of trying clays...and anything I only have 25 pounds of has been going into a "scrap bucket". 

[Mark C.]

Keep the white clays (porcelains) seperated from the stonewares.

stonewares slake better than porcelains

Keep the cone 6 away from tyhe cone 10 clays as well. Big glaze fit mess if you mix these two up

[MFP]

Hopefully I will settle on two clays soon and be past this part.  Good advice though. Thank you 

[Hulk]

No problems (so far) recycling mid fire stonewares - keep slop, allow clay to thoroughly dry, slake (add slop back, and just enough water to mix easily), mix thoroughly, dry to desired consistency (plaster slabs), wedge, wedge.... throws and works fine. I'm keeping each clay separate, particularly the light red and bmix from the buff and dark red, as they behave differently...

[MFP]

That's the method we used at the Art Center....but we were only dealing with one clay. We had a pit under the sinks to catch all the slip in two  55 gallon drums. When those would finally get full of thick slurry...we would have a plaster bat  drying marathon going on. Best handle clay ever.   I cast myself a 60 pound plaster bat for the same purpose now---in fact one of the first things I did when setting up the studio so it would be dry enough by now to work. .