Patty Gray dam mold set-up information

We were excited to open our newly shipped order from our wholesaler D & L Art Glass Supply the other day because among other things,  we also bought two Patty Gray 8" x 10" x 1/2" fusing dams!  We've been interested in Patty Gray's fused glass techniques and work for some time now especially after viewing pictures from some of her classes!  Maybe someday we will be lucky enough to attend one of her fusing classes!  Until that time, we will be on our own.

To use as our own studio's future reference and for anyone else who reads our blog and is also unsure how to set up their mold, we thought it would be helpful to share this mold's set-up information especially since it has specific sizes and layout that should be followed!

This mold is designed to produce a glass slab 8" x 10" and up to 1/2" thick with rounded edges and will require no coldworking.  The glass can be used as a finished piece or slumped to shape or even be sliced into design elements for later work.  Use cut sheets, strips, scrap, frit, rods or any form of glass that inspires you.

New mold preparation:
Use MR-97 (Boron Nitride Mold Release for Glass Casting and Slumping)
Spray mold holding can and mold upright; only spray for 3 seconds.  Wait 5 minutes and spray again for 3 seconds.  Cut ThinFire, Papyros, or comparable kiln shelf paper to 7-7/8" x 9-7/8" and put on the bottom of mold before fusing.

Filling the mold:
Cut base glass to 8" x 10" and notch the corner (about 1/8") so the glass will fit into the tray.  Design your piece to have at least two layers of glass- up to 4 layers or 1/2" thick.

Placement in kiln:
For best results, elevate your mold from the kiln floor with kiln posts, placing the posts under only the edges of the mold.

8" x 10" Patty Gray Mold Firing Schedule

Degrees                Target                  Hold time
per hour                Temperature    

150°                      1000°                  15 minutes

300°                      1225°                  15 minutes

AFAP                   1470°                  30 minutes
As fast as possible                          

AFAP                    950°                    1 1/2 hours

100°                      700°                     10 minutes

Off

Open when room temperature

After the mold has been used:
Spray mold with MR-97 only lightly (about 2 seconds and only around the inside of mold edge).  Cut shelf paper to 7-7/8" x  9-7/8" and put on the bottom of the mold before fusing.  Cut base glass to 8" x 10" and notch the corner (like stated above) so that the glass will fit into the tray.  The design the piece as usual!

Update:  12/13/12

We think that it would be best to slow down the final ramp up temperature on thicker pieces.  We noticed that on one of our thicker finished plates that the center had indented and thinned out, it was possibly going to form a bubble in that area.

Perhaps it would help to ramp up 200°  per hour, to get to 1225°  .   Then instead of ramping up AFAP, (as fast as possible), to 1470°  we suggest the kiln be ramped up at approximately 400°  per hour instead.