dark edges

[amer84]

I see sometimes a dark color on the margin of zirconium cores eventhogh I dibbing for 2-3 seconds and use new base any body can help

 

[Hary]

are you using low fusing porcelain if yes, are you using die separator if yes, it could be your die separator with the low fusing porcelain would leave a black unburned separator.

 

[BobCDT]

After dipping the green state zircomia blow dry and put on a tissue with the margin side facing up. Not sure if this is the problem but could be.
Bob

 

[paulg100]

Better still, dont colour your zirconia.

do it at the ceramic stage.

 

[amer84]

thanx for replay
I mean the core before ceramic processing

 

[ed 3]

yes, it is separator and not only on zirconium like that also emax press ,you can easily sandblast it off