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Packing Sculptures Finished With Low-Fired Barnard Slip


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When I unwrapped my figurines at my last show, tiny pieces of barnard slip came off. Bubble wraps and air pillows used for the packing must have rubbed it off during the transit. You may guess how disappointed I was. I need your help in order to prevent this from happening again.

 

I experimented with barnard clay slip in the following 3 sculptures. After brushing the slip on the bisque-fired pieces, the African boy (on the left) was fired to cone 5, and the girl, to cone 04. The man under a toad was fired to cone 04 as well. In order to darken his skin tone, I finished it with layers of thin oil paint.

 

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The African boy survived the shipment without problems. However, a tiny bit of barnard slip had come off from protruded areas of the other low-fired pieces (the upper lip of the African girl and an eyebrow of the man), and white clay body underneath was showing. Sorry, but I have no photo of the damages, as I managed to repair them during the show.

 

A seasoned exhibitor at the show instructed me to wrap my sculptures in polyurethane (painters plastic) first. According to him, nothing sticks to polyurethane wrap. Do you suggest anything else? As my sculptures are getting more complex, I have to secure them well with bubble wraps and air pillows.

 

Thank you in advance.

 

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Thank you for responding to my question so quickly. My slip is straight barnard clay. I'm such a beginner I've never experimented with a flux. Could you please share a recipe with me? By adding a flux to the slip, does the finished appearance change? I could try applying the slip at the leather-hard stage for some simple figurines, but for complex ones, I would like to bisque-fire them first.

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My guess is the barnard is not melting enough at low-fire temps, which is why the cone 5 fire statue did okay and the others -- all fired at 04 -- chipped or did not melt and adhere. 

 

Try mixing 50/50 barnard and borax or gerstley borate.  Of 50/50 barnard and frit 3134.  Try a couple test tiles to see how temperature works and whether the additions affect color.

 

You will get darker color at higher temperatures.

 

And, be watchful of the barnard dust . . . it can have a high percentage of manganese in it. 

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Thank you again, bciskepottery. I agree with you that barnard clay probably needs mid-fire temps to adhere well. May I ask you basic questions? Can the borax mentioned in your recipe be 20 Mule Team Borax, which is  Sodium tetraborate? I suppose gerstley borate and frit 3134 are sold only in ceramic stores, right? If so, I have to order them online.

 

I googled "manganese dust." It's not only hazardous to health, but also flammable. I will make sure to wear a mask and goggles when handling barnard clay.

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