Enamel Colors » Discussions

black spots on flux

• aarti chordia

  

  Member
   

  June 18, 2011

  i have been making small cloissonie pendants recently....i use to first fire my peice with flux and den place the wires and refire.i use to get perfect results. Now i started to make some more peice with the same process, but as i do my first fire now, my peice is full of black burnt spots after my first fire.....i see to it that my peice is oil free and clean....still i m facing this problem....when i started...my first two peices were perfect and this problem started from the third peice and still is on...

  i have been using the same furnace and trivet previously also....

  i have attached 1 picture, though its not very clear, still my problem can b understud.

  plzzz guide me where m i goin wrong.....

  i really need to know....because this is first time, i m facing such an issue....

  thank you.....waiting for replies.......

  i have been making small cloissonie pendants recently....i use to first fire my peice with flux and den place the wires and refire.i use to get perfect results. Now i started to make some more peice with the same process, but as i do my first fire now, my peice is full of black burnt spots after my first fire.....i see to it that my peice is oil free and clean....still i m facing this problem....when i started...my first two peices were perfect and this problem started from the third peice and still is on...

  i have been using the same furnace and trivet previously also....

  i have attached 1 picture, though its not very clear, still my problem can b understud.

  plzzz guide me where m i goin wrong.....

  i really need to know....because this is first time, i m facing such an issue....

  thank you.....waiting for replies.......

• Edmund Massow

  

  Member
   

  June 18, 2011

  The reason could be
  1) the on sieved enamel shift was too thin
  2) the firing time was too short
  3) the firing temperature was to low.
  So as the picture looks, (next the spots the flux is not realy clear) I think number 2 and 3 are the cause in this case. Fire a bit hotter and if nescessary, fire a bit longer.

  edmund

  www.emailkunst.de

  The reason could be
  1) the on sieved enamel shift was too thin
  2) the firing time was too short
  3) the firing temperature was to low.
  So as the picture looks, (next the spots the flux is not realy clear) I think number 2 and 3 are the cause in this case. Fire a bit hotter and if nescessary, fire a bit longer.

  edmund

  www.emailkunst.de

• aarti chordia

  

  Member
   

  June 18, 2011

  thankx for d reply....il jus try it again n let u know,but  does this kind of things happen if the peice is underfire.....

   

  thankx for d reply....il jus try it again n let u know,but  does this kind of things happen if the peice is underfire.....

   

• Edmund Massow

  

  Member
   

  June 18, 2011

  Yes, next an unclean surface, such results are the consequences of an underfiring.
  Edmund

  Yes, next an unclean surface, such results are the consequences of an underfiring. Edmund
• Trish White

  

  Leader
   

  June 18, 2011

  Hi Aarti,

  It looks to me like your first coating was too thin and perhaps with all the dots I see, not dry enough before it went into the kiln. Many times if the klyr fire has not dried thoroughly, it will cause little bursts of bubbles on the surface. So sift a nice layer across the top- make sure you don't see any metal through the sifted glass, then place on top of the kiln to dry thoroughly before firing.

  Hi Aarti,

  It looks to me like your first coating was too thin and perhaps with all the dots I see, not dry enough before it went into the kiln. Many times if the klyr fire has not dried thoroughly, it will cause little bursts of bubbles on the surface. So sift a nice layer across the top- make sure you don't see any metal through the sifted glass, then place on top of the kiln to dry thoroughly before firing.

• Edmund Massow

  

  Member
   

  June 18, 2011

  Trish's argumentation is right. You must dry the piece before firing very well. But if it into the kiln comes wet, one gets realy little explosions in the kiln.  The black areas  are mostly bigger and the outlines are more irregular. The "spots" are not so round.

  

  Trish's argumentation is right. You must dry the piece before firing very well. But if it into the kiln comes wet, one gets realy little explosions in the kiln.  The black areas  are mostly bigger and the outlines are more irregular. The "spots" are not so round.

  

• aarti chordia

  

  Member
   

  June 18, 2011

  thanks a lot edmund and trish....as edmund had told me to do a thick layer of flux and give it good fire....on doing so...i acheived desired results with no such black spots.

  i later realised that the seve i was using was of very fine mesh, and so i was actually doin a thin layer.

  thanks for the replies...it really helped me.

  thanks a lot edmund and trish....as edmund had told me to do a thick layer of flux and give it good fire....on doing so...i acheived desired results with no such black spots.

  i later realised that the seve i was using was of very fine mesh, and so i was actually doin a thin layer.

  thanks for the replies...it really helped me.

• Vivek Das

  

  Member
   

  June 18, 2011

  Hi Aarti, It is problem of glue which you are using. I know recently you are using 

   

   

  Hi Aarti, I understand it is problem of glue. I know recently you have started using CMC. This is a very strong type of glue and should be used very dilute. Remember if you have prepared fresh glue for your latest work. If yes it is 100% glue problem as everyone guessing. Preparing glue from powder CMC must be kept overnight. Than dilute it. It is better you keep a record how much powder you are taking & how much water you are mixing. When you get to know a proper proportion keep a record and follow the same for future use. Enameling is like horse riding, initially horse will kick you but when it becomes friendly will invite you for a ride. These are initial problems and you will overcome very soon. I suggest not to use glue all the time. use where it is required. Regards

   

   

   

   

   

   

  Hi Aarti, It is problem of glue which you are using. I know recently you are using 

   

   

  Hi Aarti, I understand it is problem of glue. I know recently you have started using CMC. This is a very strong type of glue and should be used very dilute. Remember if you have prepared fresh glue for your latest work. If yes it is 100% glue problem as everyone guessing. Preparing glue from powder CMC must be kept overnight. Than dilute it. It is better you keep a record how much powder you are taking & how much water you are mixing. When you get to know a proper proportion keep a record and follow the same for future use. Enameling is like horse riding, initially horse will kick you but when it becomes friendly will invite you for a ride. These are initial problems and you will overcome very soon. I suggest not to use glue all the time. use where it is required. Regards

   

   

   

   

   

   

• Jim Jordan

  

  Member
   

  June 18, 2011

  I had a similar problem once, it turned out to be small flakes from my trivet.  I had used the trivet so long that it formed a scale and the scale was flaking off.  Someone on enamel forum suggested that I boil the trivet in alum.  This removed the scale, but made the wire mesh that the trivet was attached to really loose.  I ended up buying a new trivet and that solved the problem.  Jim

  I had a similar problem once, it turned out to be small flakes from my trivet.  I had used the trivet so long that it formed a scale and the scale was flaking off.  Someone on enamel forum suggested that I boil the trivet in alum.  This removed the scale, but made the wire mesh that the trivet was attached to really loose.  I ended up buying a new trivet and that solved the problem.  Jim
• Julie Holmes

  

  Member
   

  June 18, 2011

  It looks like the problem has already been answered but I thought I would add my two cents about black spots.  I have never had a problem with them when using my own kiln, but I used to attend a glass on copper group and made some pieces using their kilns. On some pieces I got a dusting of small black spots in the entire piece, not visible to the naked eye, but visible on the photographs.  I'm blaming it on the copper enamelists's scalex turning into ash and landing on my piece.  I used the kiln that was dedicated for silver enameling, so I'm betting it didn't happen in the kiln, but while sharing the cooling racks with the copper pieces.  It's just a guess mind you, I really don't know for sure if that's the cause.  I do try to keep dust to a minimum and rewash my enamels frequently while working, it seems to help.

  It looks like the problem has already been answered but I thought I would add my two cents about black spots.  I have never had a problem with them when using my own kiln, but I used to attend a glass on copper group and made some pieces using their kilns. On some pieces I got a dusting of small black spots in the entire piece, not visible to the naked eye, but visible on the photographs.  I'm blaming it on the copper enamelists's scalex turning into ash and landing on my piece.  I used the kiln that was dedicated for silver enameling, so I'm betting it didn't happen in the kiln, but while sharing the cooling racks with the copper pieces.  It's just a guess mind you, I really don't know for sure if that's the cause.  I do try to keep dust to a minimum and rewash my enamels frequently while working, it seems to help.