Gray scum
Posted: Tue Feb 26, 2013 2:23 pm
I have been making a jewelry piece for a customer that has a white (wissimach white) flower on a pink (bullseye petal pink opal) background. I fused the background separately with no problem and then tack fused the flower with the following schedule:
AFAP ---> 1050 10
100 ---> 1250 10
AFAP ---> 1400 10
AFAP ---> 960 10
300 ---> 750 0
500 ---> 114 0
I have a small Paragon kiln and this schedule has always worked great for me for full fusing (with the top temperature raised to 1500) so I just amended it for tack fusing. I got exactly the amount of fusing I wanted with this schedule.
When I took the piece out, I noticed that one of the petals had a gray scum all across the top. Even though it looked different from the scum you get on glass when you haven't cleaned your edges well enough, I thought maybe I hadn't washed the grinder scum off of that petal, so I sanded it with a diamond hand block, washed it well with vinegar and water, and put it back in the kiln with the same schedule.
Well, I just took it out and now there is a little bit of the gray scum on the side of the pink glass that definitely wasn't there before. It is really close to the surface, since a few seconds of sanding with the hand pad took it off both times.
Now I need to put the piece back in the kiln to fire polish out the scratches from the sanding, but I am afraid just putting it back in will result in more of this scum elsewhere on the piece. Does anyone have any idea what is causing this? Any suggestions for this firing? I know I can take it to a lower temp this time (and could have last time) since I am not tack fusing any more, just fire polishing.
Thanks so much in advance for any help.
--jodi
AFAP ---> 1050 10
100 ---> 1250 10
AFAP ---> 1400 10
AFAP ---> 960 10
300 ---> 750 0
500 ---> 114 0
I have a small Paragon kiln and this schedule has always worked great for me for full fusing (with the top temperature raised to 1500) so I just amended it for tack fusing. I got exactly the amount of fusing I wanted with this schedule.
When I took the piece out, I noticed that one of the petals had a gray scum all across the top. Even though it looked different from the scum you get on glass when you haven't cleaned your edges well enough, I thought maybe I hadn't washed the grinder scum off of that petal, so I sanded it with a diamond hand block, washed it well with vinegar and water, and put it back in the kiln with the same schedule.
Well, I just took it out and now there is a little bit of the gray scum on the side of the pink glass that definitely wasn't there before. It is really close to the surface, since a few seconds of sanding with the hand pad took it off both times.
Now I need to put the piece back in the kiln to fire polish out the scratches from the sanding, but I am afraid just putting it back in will result in more of this scum elsewhere on the piece. Does anyone have any idea what is causing this? Any suggestions for this firing? I know I can take it to a lower temp this time (and could have last time) since I am not tack fusing any more, just fire polishing.
Thanks so much in advance for any help.
--jodi