- Drape mold devit
I am having issues with Tekkta clear 4mm devitrifying on drape molds only. This happens consistently to glass that it has no signs of devit after the full fuse fire at 1500. I am using bisqued clay bowls that I have thrown and they have been coated with Hotline Primo Primer. The primer has been been pre-fired to 500 with a 20 min hold. This is not a texture issue on the clay but a true haze or devit. It is especially bad on the corner from where the base of bowl turns to the sides. However it is consistent where the glass comes in contact with the clay IMPORTANT* I do not have the same issue slumping inside the same bowl.
I am attaching an image showing a textured paper blurred out where there is glass.
I don't have a production date on the glass and consistently use Tekta BE1100048F
These are a component to a sculpture (that is epoxied together at a later time) this section looks like your typical corral fused design.
I use a paragon 22 x 22 x 36 glass kiln. Lid elements and one section of side element
I use the following slump firing schedule for all of my standard slump and drape molds:
300 per hour to 1175/1200 No hold (depending on the thickness and depth of slump) The mold is situated in the center of a 20" round shelf.
Any thoughts or help you can offer would be terrific.
Michelle
St. Louis, MO