baldwin_kevin
Member
Hi, Silver Forum.
PROBLEM TO SOLVE
My cemented silver is all agglomerated, lumpy, and shows crystal faces. I need the finest, most dispersed silver sludge/powder possible.
BACKDROP
I am a graphic artist who wants to branch out into silver-clay jewelry production. In art, I experiment a LOT before landing good designs, so I want to make lots of my own artisanal silver clay to experiment with. And it doesn't have to be perfect silver clay.
In the past, I have cemented 20 or 30 ounces of silver powder to create silver clay. Yes, I know all the standard warnings: The clay-making process is super-difficult, what with proper starch binders, organic conditioners, sintering temperature ranges, auto-fluxing, etc. I am currently climbing all these very real obstacles.
But as everyone here knows, the one saving grace is that you get to recycle metal from failed experiments into your current experiments.
QUESTIONS
How can I cement a very small silver particle size (around 20 microns?) from aqueous silver nitrate using elemental copper? Would it help to add dispersants to the aqueous silver nitrate?
. . . Small silver particle size: I need fine particles for great clay body plasticity, good shape definition/retention, and easy sintering.
. . . Aqueous silver nitrate: This is my current method of getting elemental silver into solution.
. . . Silver cementation using copper: I know that the resulting solid precipitate will not be 999 silver but rather silver-mixed-with-copper. For artisanal use, I am okay with this impurity.
. . . . . . BTW, to cement silver I have also used ascorbic acid (C6H8O6), but there's a HUGE drawback (which nobody discusses): In cementation, the silver particles bind with a coating of dehydroascorbic acid (C6H6O6), which later on makes sintering the silver clay object nearly impossible. The decomposition temperature of the C6H6O6 is almost the same as silver's fusing temp :-(
. . . Adding dispersants: Maybe the actual particle size is already good enough and perhaps it's just the agglomeration (lack of dispersal) that's the problem, I don't know.
. . . . . . Anyway, I have read a lot about adding methyl cellulose or PVA (= Elmer's glue) to the silver nitrate before cementing. Has anyone tried this?
. . . . . . I actually had some good results early on, adding methyl cellulose as dispersant to silver nitrate in an ultrasonic bath like this guy does. But my more recent problems with C6H6O6 coating makes me hesitate now. (Does the methyl cellulose intercede before the C6H6O6 can attach? I don't know.)
. . . Am I over-thinking this?!! Can I super-dilute the silver nitrate to achieve small particle size? Change the temperature? Can I stir vigorously (adding lots of shear force) during cementation? What have I overlooked here? I am looking for something simple that I have missed here.
CURRENTLY OUT OF SCOPE
. . . Perfection. (Small improvements are welcome.)
. . . Mechanical sifting. (I just want to cement and go.)
. . . No industrial atomizing equipment. (Who has the money for that?!)
Thanks in advance, --K
PROBLEM TO SOLVE
My cemented silver is all agglomerated, lumpy, and shows crystal faces. I need the finest, most dispersed silver sludge/powder possible.
BACKDROP
I am a graphic artist who wants to branch out into silver-clay jewelry production. In art, I experiment a LOT before landing good designs, so I want to make lots of my own artisanal silver clay to experiment with. And it doesn't have to be perfect silver clay.
In the past, I have cemented 20 or 30 ounces of silver powder to create silver clay. Yes, I know all the standard warnings: The clay-making process is super-difficult, what with proper starch binders, organic conditioners, sintering temperature ranges, auto-fluxing, etc. I am currently climbing all these very real obstacles.
But as everyone here knows, the one saving grace is that you get to recycle metal from failed experiments into your current experiments.
QUESTIONS
How can I cement a very small silver particle size (around 20 microns?) from aqueous silver nitrate using elemental copper? Would it help to add dispersants to the aqueous silver nitrate?
. . . Small silver particle size: I need fine particles for great clay body plasticity, good shape definition/retention, and easy sintering.
. . . Aqueous silver nitrate: This is my current method of getting elemental silver into solution.
. . . Silver cementation using copper: I know that the resulting solid precipitate will not be 999 silver but rather silver-mixed-with-copper. For artisanal use, I am okay with this impurity.
. . . . . . BTW, to cement silver I have also used ascorbic acid (C6H8O6), but there's a HUGE drawback (which nobody discusses): In cementation, the silver particles bind with a coating of dehydroascorbic acid (C6H6O6), which later on makes sintering the silver clay object nearly impossible. The decomposition temperature of the C6H6O6 is almost the same as silver's fusing temp :-(
. . . Adding dispersants: Maybe the actual particle size is already good enough and perhaps it's just the agglomeration (lack of dispersal) that's the problem, I don't know.
. . . . . . Anyway, I have read a lot about adding methyl cellulose or PVA (= Elmer's glue) to the silver nitrate before cementing. Has anyone tried this?
. . . . . . I actually had some good results early on, adding methyl cellulose as dispersant to silver nitrate in an ultrasonic bath like this guy does. But my more recent problems with C6H6O6 coating makes me hesitate now. (Does the methyl cellulose intercede before the C6H6O6 can attach? I don't know.)
. . . Am I over-thinking this?!! Can I super-dilute the silver nitrate to achieve small particle size? Change the temperature? Can I stir vigorously (adding lots of shear force) during cementation? What have I overlooked here? I am looking for something simple that I have missed here.
CURRENTLY OUT OF SCOPE
. . . Perfection. (Small improvements are welcome.)
. . . Mechanical sifting. (I just want to cement and go.)
. . . No industrial atomizing equipment. (Who has the money for that?!)
Thanks in advance, --K
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