This is a fantastic method for firing shoulder plates that are likely to crack or warp during the high firing process. (click on photo to enlarge)



Pour a puddle of porcelain slip that would resemble a "pancake" on the out side/top of a mold or your kiln shelf (prepare the shelf BEFORE you pour the porcelain slip on it with silica). The pancake should be larger then the object you are going to set on it. Let it the pan cake dry - turn it over at least once to prevent the edges from curling upward. I prefer to Soft fire to same cone the shoulder plate is/was softfired too so that both pieces shrink at the same rate - but its not critical that you do so as the pieces will "catch up with each other" when they each the temperature the SP was soft fired to.

 After the pancake has been softfired (or if its in the green ware stage) and prior to bisque firing, sprinkle the surface with sand or silica powder (I use fine silica powder, sifted thru a strainer)
    REMINDER! ALWAYS WEAR A MASK WHEN HANDLING SILICA SAND OR SILICA POWDER, AND WASH YOUR HANDS WHEN YOU ARE FINSIHED.

This photo shows how I sift/sprinkle the Silica on to pancake. If you don't your shoulder plate will fuse to the pancake during firing

Pancake coated with a fine, even layer of silica. You may use silica powder or silica sand if you don't have access to silica powder
Set shoulderplate onto pancake, place on prepared kiln shelf and SLOW fire to witness cone 6.
    Prepared Kiln shelf means that the shelf should have an even layer of silica powder/silica sand on the shelf. Then the pancake that has the silica powder/sand is placed on the shelf. Never place SFGW directly on a shelf for bisque firing!
What happens by using the pancake? When the porcelain begins its shrinking process during the firing, the "pancake" absorbs the friction/resistance as is moves but the shoulder plate doesn't. The pancake is actually a "carrier" for the shoulder plate. Make sure you use either silica sand or powdered silica sprinkled on the kiln shelf as you would with any porcelain object being high fired, i.e., sand/powder should be on both sides of the pancake/carrier.