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Attaching Dry Pieces To Each Other


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1 hour ago, LeeU said:

I know that Spooze & Magic Water are not the same thing. I looked at the recipe for the water, but I don't mix chemicals these days (no room to make clay/glaze/storage etc./low volume production). Is there any major-major diff 'tween the two for simple repairs (^6)? I love Spooze-it's never not worked for me.

Magic water contains two fluxes, sodium Silicate and soda ash, so theoretically the water would help keep things attached when fired as well.  Spooze contains a buttload of carbon, like an insane amount, and I don't like adding carbon to my clay, my clay is gassy enough.

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On 1/4/2018 at 8:06 PM, Sequoia Pottery said:

This has been a while, if anyone is still paying attention to this:  Recently I ran across an old patent about attaching dry ceramic objects together, like a dry handle to a dry mug.  Now I can't find it!  Here is the process as I remember it.  (1)  "machine" the two objects to fit as closely as possible.  (2) Brush the two objects with a generous coating of 4% solution of polyvinyl alcohol and allow to sink in.  (3) mix a slurry of clay body with the 4% solution of pva, coat both objects to be joined, press them together, and ...voila.  

I routinely use polyvinyl alcohol on regular mug handles and it seems to work very well, but have never tried it dry.  Does anyone have experience with this?

The idea seems to have some relationship to ceramic tape technology. The Emer's glue DIY version is described in the frequently mentioned:
Tape Casting - Alfred Grinding Room https://static1.squarespace.com/static/527ac372e4b0d4e47bb0e554/t/527fd23fe4b0f7fd724aba83/1384108607291/tape+casting.pdf
... which contains the advice
Careful consideration must be given to the firing schedule in order to allow the binder and plasticizer will burn out completely. A rate of 50 F up to 500 F is generally acceptable for this. 

 

 

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This topic perfectly illustrates the difference between a studio potter and a production potter.  Most of us may very well be some degree between the two.  The ability to recover from varying degrees of difficulties in itself is an acquired  skill.  For a production potter, the typical response is trash it and move on, but a studio potter is always pushing the envelope, so it's useful to have a bag of tricks.

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@PeterH, I'ld be willing to test some polyvinyl alcohol if I could get some without it costing a fortune for shipping. From Digitalfire: "Usually it is used as a binder for glazes, during glazing operations, before the screen printer (a water solution of polyvinyl alcohol is sprayed on the surface to be decorated). It is a strong surfactant and binding power is connected to its ability to wet particles (products having a low molecular weight exhibit low viscosities and they have a minimal effect on the viscosity of glazes or body slips). It is stable because it does not ferment. Usually suppliers propose water solutions of polyvinyl alcohol."

I'm thinking it might act like spooze if mixed into a joining slip but without the rotting? From what I've read it improves greenware strength when added to casting slips also. I remember when Lana Wilson's Magic Water recipe came out, there were a lot of sceptics about that but it has proven to be very beneficial for some. Maybe there is an application for polyvinyl alcohol for studio potters that just hasn't yet been fully explored. Glaze additive for multiple layering or refires? 

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19 hours ago, Min said:

@PeterH, I'ld be willing to test some polyvinyl alcohol if I could get some without it costing a fortune for shipping. From Digitalfire: "Usually it is used as a binder for glazes, during glazing operations, before the screen printer (a water solution of polyvinyl alcohol is sprayed on the surface to be decorated). It is a strong surfactant and binding power is connected to its ability to wet particles (products having a low molecular weight exhibit low viscosities and they have a minimal effect on the viscosity of glazes or body slips). It is stable because it does not ferment. Usually suppliers propose water solutions of polyvinyl alcohol."

I'm thinking it might act like spooze if mixed into a joining slip but without the rotting? From what I've read it improves greenware strength when added to casting slips also. I remember when Lana Wilson's Magic Water recipe came out, there were a lot of sceptics about that but it has proven to be very beneficial for some. Maybe there is an application for polyvinyl alcohol for studio potters that just hasn't yet been fully explored. Glaze additive for multiple layering or refires? 

Min - see pm

I've failed to find the patent mentioned earlier, but this one suggests that a wide range of binders can be used:
Ceramic composite article prodn. - by bonding parts with binder of ceramic filler in aq. polymer soln.
https://patents.google.com/patent/DE3938933A1/en?oq=+Bibliographic+data:+DE3938933+(A1)+―+1990-05-31++++++|+++++In+my+patents+list+++++|+++++Report+data+error+++++|+++++Print+++Ceramic+composite+article+prodn.+-+by+bonding+parts+with+binder+of+ceramic+filler+
(A) In the prodn. of a ceramic composite article by bonding two articles of the same ceramic material using a binder and then sintering, the ceramic articles have the same thermal shrinkage at room temp. to the sintering temp. and the binder consists of the same ceramic material as filler in an aq. soln. of a water-soluble polymer. (B) A binder, for bonding ceramic articles, consistse of a ceramic filler in an aq. soln. of a water-soluble polymer. Pref. the polymer is one or more of methylcellulose, carboxy carboxymethyl cellulose, hydroxyethyl cellulose, polyvinyl alcohol, polyacrylic acid, polyacrylamide and polethylene oxide. USE/ADVANTAGE - The binder is esp. useful for binding calcium phosphate type ceramics to produce a bio-material. The process and binders low cost and avoid leaching out of noxious substances during use of the article.

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Mildly depressing information about polyvinyl alcohol

Polyvinyl Alcohol: Properties, Uses, and Application https://www.toppr.com/bytes/polyvinyl-alcohol/
There are two ways in which the 4% aqueous solution of Polyvinyl alcohol (PVA) may be created. The first uses a conventional heating method, the second uses the microwave heating method. The latter is easier to conduct and is less time-consuming. Once the 4% PVA solution is made, it can last between 6 and 8 weeks. Generally, it is advisable to refrigerate this solution, which supports the growth of bacteria.

When making the Polyvinyl alcohol solution, it is recommended to use tap water, as bacteria grows faster in PVA containing distilled water.

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