All, more photos from pattern-maker Bernie Perch, taken at the foundry...thanks, Bernie!
Finished cores ready for placement. All made from the same core box with three different sized spacers, the wide lower part fits into the core print to lock the cores in place.
The cope (top of the flask) and the drag (bottom of the flask) before they are placed together. The pieces are heavy but easily moved with a hoist.
Imprint of half of the whistle bell in the drag along with the gates where the molten metal flows. The large pins align the two parts of the flask along with the dimples in the sand.
The placement of the core for the shortest chamber. Even though it is locked in place, a "chaplet" (spacer) is placed between the core and the sand to keep it properly spaced. This core must be precisely placed and because it is not keyed for exact placement, a gauge (not shown) is used to place it exactly in place. If these cores are out of place it will result in a hole forming in the step part of the whistle and the inner walls will not align with the fins on the outside. Several other gauges are used to check the alignment of the other two cores. They are really redundant, but it doesn't hurt to double check everything!
The placement of the second core. Again, a chaplet is used to space the two cores.
All three cores in place. Again, chaplets are used for spacing.
The block of sand after removal from the flasks. The sand is chemically hardened. Shown are the openings for pouring the metal and the vent.