Copper carbonate sieving problem

[VictorM]

Hello everyone,

 

So this is my first post here, and I remember seeing one similar to it but I just couldn't find it unfortunately... The thing is, everytime I use copper carbonate as a component of a glaze, after I've mixed the slurry and when I'm about to sieve it, I end up getting some small green balls stuck in the sieve, even though the powder I use seems pretty fine. My first question is wether someone know why this happens and the second one is how to prevent it since those green balls should be in my glaze hehe.

Thanks in advance!

[neilestrick]

Are you dry mixing the glaze before adding it to water? Some materials like to clump more than others, so even just mixing it with one or two of the other ingredients may help.

[VictorM]

So, the way I do it is I weight the materials separately and then add it to the glaze bucket which already contains water! I'll try then to dry mixing some ingredients to prevent that problem. Thanks!

[Mark C.]

I mixed a copper carb  and cobalt carb glaze yesterday. 10,000 grams . I weight the materials like you and toss them into a bucket of water like you.

Then I use a jiffy mixer on a drill. to beat the snot out of them then sieve them thru a Talisman seive which has brushes that force the material thru the sieve. Zero issues

I'm guessing you are not power mixing with a beater of sorts which is cheap and easy to do. In terms of a seive use a plastic scraper like a credit card to force the lumps thru. ig there are any after power beating. If you are mixing small amouts just use a blender from the thrift shop and it will pour thru any size  seive after a few minutes on margarita speed

I do this almost every week for decades and never dry mixed-always wet mix (less dust)

The power mixer on a drill is a key tool-I have many kinds but use the jiffy mixer heads that come in many sizes  depending on the bucket size you are mixing

 

[oldlady]

victor, there is a member here, glazenerd, who advised me on how to fix the problem i had with copper carb.   i used to buy it, (1970s) as a greyish-green powder but now it is only available in a bright green that looks more like lime jello.

glazenerd advised me to put vinegar over the powder in a bowl until the powder was covered with vinegar and let it dry.      a scum formed on the top when it dried, only a couple of days for my amount.   i tossed the   scummy stuff and the powder left works very well.   i sieve through a 60 mesh sieve and use lots of green glaze.  no problems.

thanks, nerd, hope i said that at the time.

[VictorM]

21 hours ago, Mark C. said:

I mixed a copper carb  and cobalt carb glaze yesterday. 10,000 grams . I weight the materials like you and toss them into a bucket of water like you.

Then I use a jiffy mixer on a drill. to beat the snot out of them then sieve them thru a Talisman seive which has brushes that force the material thru the sieve. Zero issues

I'm guessing you are not power mixing with a beater of sorts which is cheap and easy to do. In terms of a seive use a plastic scraper like a credit card to force the lumps thru. ig there are any after power beating. If you are mixing small amouts just use a blender from the thrift shop and it will pour thru any size  seive after a few minutes on margarita speed

I do this almost every week for decades and never dry mixed-always wet mix (less dust)

The power mixer on a drill is a key tool-I have many kinds but use the jiffy mixer heads that come in many sizes  depending on the bucket size you are mixing

 

Thanks for the reply! The thing is my jiffy mixer died 3 days ago unfortunately so I did have to hand-mix it, but I remember having that problem even when using power tools. I definitely think the talisman sieve would help (man it's dream come true to get my hands on one) but maybe the credit card through the sieve might just do the trick. Thanks!

 

[VictorM]

1 hour ago, oldlady said:

victor, there is a member here, glazenerd, who advised me on how to fix the problem i had with copper carb.   i used to buy it, (1970s) as a greyish-green powder but now it is only available in a bright green that looks more like lime jello.

glazenerd advised me to put vinegar over the powder in a bowl until the powder was covered with vinegar and let it dry.    boil and bubble, bubble, bubble.   a scum formed on the top when it dried, only a couple of days for my amount.   i tossed the sheet of scummy stuff and the powder left works very well.   i sieve through a 60 mesh sieve and use lots of green glaze.  no problems.

thanks, nerd, hope i said that at the time.

Wow, definitely never heard of that before! When you say boil, do you use a regular pan? Will that make it unusable for food afterwards since you are boiling a toxic material? The copper carbonate I get here in Brazil from my supplier is a very dark green, not bright at all, so that might do the trick. Thanks!

[Min]

4 hours ago, VictorM said:

Wow, definitely never heard of that before! When you say boil, do you use a regular pan? Will that make it unusable for food afterwards since you are boiling a toxic material? The copper carbonate I get here in Brazil from my supplier is a very dark green, not bright at all, so that might do the trick. Thanks!

Don't boil the vinegar and copper carbonate!!! I believe @oldlady is referring to an active (bubbling) chemical reaction between the two at room temperature.

[liambesaw]

8 hours ago, oldlady said:

victor, there is a member here, glazenerd, who advised me on how to fix the problem i had with copper carb.   i used to buy it, (1970s) as a greyish-green powder but now it is only available in a bright green that looks more like lime jello.

glazenerd advised me to put vinegar over the powder in a bowl until the powder was covered with vinegar and let it dry.    boil and bubble, bubble, bubble.   a scum formed on the top when it dried, only a couple of days for my amount.   i tossed the sheet of scummy stuff and the powder left works very well.   i sieve through a 60 mesh sieve and use lots of green glaze.  no problems.

thanks, nerd, hope i said that at the time.

Just so you know for the future, this makes copper acetate, a water soluble copper salt, and is a more toxic and problematic version of copper for glazes.  It will flocculate your glaze and may recrystallize over time.

[oldlady]

victor.   i am sorry if i confused you.    i did not say that you should boil anything.   do not do that.    maybe you could contact glazenerd to ask what you need to know.   i am no expert on glazing.

@min,  thank you for realizing that english is confusing sometimes and stopping victor from an error on my part.

[Min]

@VictorM, is there another supplier you can get the copper carbonate from that has a finer mesh size? If not I'ld just keep using the copper you have and screen out the coarse particles or try running it through a blender for a few minutes with some water then sieve and dry it out and see if that breaks down the larger particles.