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repairing grenware?

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yes, there is a recipe for "score no more" in my glaze book.  will dig it out.  if you use more than one clay, mix each one separately and use the right one for each clay. dry powdered gum arabic from Georgie's supply

 

 

 Score no more               attributed to pat horsley

100 grams dry clay body

2 grams dry gum arabic

2 grams custer feldspar

2 grams bentonite 

 

mix dry ingredients thoroughly.  add HOT water, mix and let it sit for awhile, maybe overnight.  should be like peanut butter consistency, if too wet let evaporate or remove excess water.

 

add 1/4 teaspoon sodium silicate 

pinch of epsom salts

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Would this work on a piece that completely broke off?  I was making a bead rack/tree.  I let it dry very slowly, but when I moved it to the kiln room to be bisque fired, I bumped it on the shelf and a small triangle that will hold the wire broke off. I saved it and was going to try to repair it another time. I spritzed the rack with a mist of water, wrapped up inside plastic, spritzed the outside of the bag with water, put another bag on, and then did the same and added a third bag.  I figured that would keep it safe until I could read about what to do.

 

I really like the shape and design on this rack but I am thinking I should just make a new one. But if this would work WOW. I would love it.

Carole

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Georgies is great! Id bet the hot water is to dissolve the gum Arabic, it's the same thing used as binder for watercolor paint and can be bought in liquid form from any well stocked art supply shop but then you don't know the dilution compared to the recipe. Since it is syrupy, I'd assume that's why some other other variations use corn syrup...the kitchen cupboard is easy to raid!

 

I am glad I saw this thread, I'd thought about trying a commercial greenware mender but since the pieces I have are just rim chips this sounds more practical...usually I just scrap broken pieces, but I have two that I invested 4+ hours each in carving, so I'll see if this works for porcelain since I've got nothing to lose since right now the effort is for naught anyway!

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please let us know.  the original poster promised but there is nothing here about results.  i would hate to pass on a recipe that does not work.  i know that score no more works because Jan Richardson uses it on her enormous stoneware slab boat sculptures and on her thin paperclay bowls that are almost translucent.

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I just repaired a green stoneware pot that I clumsily cracked part of the rim off while moving it. I used the formula that I'm sure was listed here a while ago. One third each of the clay body, vinegar and maple syrup. I first applied vinegar to the broken edges then used the wet clay (more slippy than solid) as part of my mixture which I brushed on in layers, letting it completely dry in between. That fixed it and it was successfully bisque fired.

 

This mixture was also used to successfully fill in a small crack at the bottom of a bowl.

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On 8/27/2012 at 8:32 AM, Marcia Selsor said:

Use a toilet paper /paper clay patch. Mix it up in the blender.

Mix

your clay in dry powder form, dash of vinegar, drop or two of sodium silicate

toilet paper that has soaked overnight

stir in the blender. Use about 15% tp to your volume of powdered clay.

dampen the edges before applying.

Marcia

 

Can I use Darvan 7 in place of sodium silicate?

TIA

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On 8/27/2012 at 6:54 PM, morah said:

 

Marcia, I am sorry to be such a novice but would you mind explaining about powdered clay? Do you just save the dried up clay powder (that I thought I should avoid because its not safe to breathe) or is there some process to make it? Also, is there any particular type of vinegar- wine, white, etc.? And last but not least, what is sodium silicate and where do you get it? Thanks. Morah

sorry for the delay. I was in Barcelona with my husband who was at a conference and who is living in DC for the next 2 years. . Powdered clay is ground up powder of the clay you are repairing. You can use a rolling pin. You don't need much. Wear a dust mask.

Get liquid sodium silicate or you'll have to mix ir yourself. Get it at a ceramic supply shop.

 

Marcia

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12 hours ago, Marcia Selsor said:

I would think so since it is probably acting as a dispersal agent.

Is the Sodium Silicate also in there as a "glass former"?

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3 hours ago, Marcia Selsor said:

yes but it is only a few drops. more like a touch of flux, not quite anything like a glaze portion.

 

Got it!  Thanks for the clarification.  Does Darvan do that?

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22 hours ago, Mark C. said:

let us know if that works???

I tried this on Saturday and the first thing I checked on when I walked into the studio was to see it worked out. So far so good but I guess I'll find out for sure after its bisqued.

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17 minutes ago, RonSa said:

Will Do Babs.

 

16 hours ago, RonSa said:

I tried this on Saturday and the first thing I checked on when I walked into the studio was to see it worked out. So far so good but I guess I'll find out for sure after its bisqued.

ye of little faith!

 

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I'm actually trying new mending methods, as it not only comes up with my High School students, but the Middle School teacher, usually borrows some of my mending slips.  So I'm trying to build a better mousetrap, so to speak.  The Spooze has been my go to for years.  It does a great job.  It holds well, sets fast, and can be used right before firing.  I just find that the join isn't quite as strong as the surrounding areas.  Using Magic Water in conjunction with the Spooze seems to help a bit.  But lately I've been using a "Super Saturated" Slip.  Just a deflocculated slip, with more clay powder added in.  I like it, because, when applied to bone dry clay, it grabs and holds almost instantly.  I also use this in conjunction with Magic Water.  I am still determining, if the join is any stronger than other methods I've used.  

Of any of the methods, for fixing wares, I've found the best method, is what I usually tell students, when they bring the damaged project up to me:  Me:  "What happened?"  Student:  "I broke my project."  Me:  "Yeah, I wouldn't have done that, if I were you..."

Babs and Rae Reich like this

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did you take notes

you can depoit$ straight into my bank, ac no 0000 0000 0000 just like my bank balance after visiting pottery suplies:--))))))

glad it worked for you, hope you don't to use it often:-)

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So I took one of my demo wheel projects, one that I cut in half with the wire, to show consistent thickness, and used a combination of Magic Water and my saturated slip, to put the two halves back together.  The seam is still visible, but that is mostly due to me not worrying about aesthetics as much as performance.  After firing, no cracks were visible in the mend, and it held up to the stress of me trying to pull the two halves apart.  Is it as strong as the rest of the piece?  That I can't say, but it is a pretty good mend!

A real test will be with my Art Club's Raku projects.  I made a super saturated Raku slip and used the same process to fix some of the breaks on their projects.  They came  through the Bisque just fine, but we will see how they do with the thermal shock of the actual Raku firing.  

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