removable refractory die issues

[wwcanoer]

I need some help and advice regarding feldspathic veneers on pinned refractory die's. I googled it, and came up with a step-by-step outline from GC

http://www.gcamerica.com/lab/products/GC_Initial/article9-InitialAL_Polypour_OrbitVest.pdf

The instructions seemed pretty straightforward, and I had all of the "ingredients", but my end result was less than pleasing regarding the model work. As with most things in life, I would assume that there is a learning curve, but as you can tell from the photos, but none of my dies come even close to fully seating. Best I can tell, there is nothing in the pinhole that is preventing these from seating fully.
The instructions say to:
Allow the investment set for at least 90 min. (figure 8)
Then, to create the base, fill the remainder of the polyvinyl siloxane with fast setting stone (mounting stone). The short setting time of mounting stone prevents moisture from absorbing into the investment

The one thing I know I did not follow, was let the investment set for 90 min., I only let it set for an hour, and then separated the dies from base only after 5 min. Is this what caused my problem? Was the quick setting stone, SNAP Stone, still expanding despite being "set"?


Thanks

 

[martintay]

Maybe make them on a tray - or do a Geller "Carrot" model.

 

[doug]

We have a system here called "Uni-pin" that works very well for doing removable refractory dies.
http://products.dentalproductsreport.com/community/DisplayAd.asp?id=6476
We used this system for quite a few years successfully. It has a learning curve with a lot of cursing, but works great when you get the hang of it.

 

[Bobby Orr ceramics]

steam clean the pin hole from the bottom of base and the refractory die should drop down.

 

[wwcanoer]

steam cleaning worked, thankssssssssss