Strange Happenings
Posted: Sun Apr 07, 2013 5:50 pm
It seems that on projects that require more grinding than usual, I end up with devitrification no matter how well I scrub and clean the pieces. I’ve had great success treating this devit by coating with Super Spray and re-firing to 1350 for 2 to 3 minutes.
On my latest project, I had hoped to avoid the devit monster and pre-coated the fish that I was contour fusing to a 6mm plate. In the same firing, I threw in some small test coupons with ‘Lo to High fire Decals on them. I was testing for color fade, texture etc. The instructions for the decal material stated to vent the kiln during the burn off phase which I did (several inches). I’m assuming you need to vent the gases created during this step.
When I opened the kiln the next day, my blue fish had turnes RED! (No red herring jokes, please!) I’m thinking the gasses from the decals reacted with the Super Spray. I've used this glass before so I don't think it's a compatibility issue.
Has anyone else had this happen? Is there another explanation?
To remove the red, I used a Dremel to grind the edges of the fish and wet sanded / chemically etched the surfaces. Then I re-fired to polish. I think I will have to re-apply the Super Spray and fire one more time (by itself!) to be satisfied but I think it’s salvagable.
Jim
On my latest project, I had hoped to avoid the devit monster and pre-coated the fish that I was contour fusing to a 6mm plate. In the same firing, I threw in some small test coupons with ‘Lo to High fire Decals on them. I was testing for color fade, texture etc. The instructions for the decal material stated to vent the kiln during the burn off phase which I did (several inches). I’m assuming you need to vent the gases created during this step.
When I opened the kiln the next day, my blue fish had turnes RED! (No red herring jokes, please!) I’m thinking the gasses from the decals reacted with the Super Spray. I've used this glass before so I don't think it's a compatibility issue.
Has anyone else had this happen? Is there another explanation?
To remove the red, I used a Dremel to grind the edges of the fish and wet sanded / chemically etched the surfaces. Then I re-fired to polish. I think I will have to re-apply the Super Spray and fire one more time (by itself!) to be satisfied but I think it’s salvagable.
Jim