An insulating riser is a pouring cup / riser that molten metal is poured into. The insulating properties of the riser keeps the metal molten longer thus helping to eliminate shrinkage defects in the part. Since the top of the riser is wider than the bottom it makes pouring easier too. Another advantage is that the riser keeps loose sand from entering the mold as can happen in a mold with just a riser cut in the sand.
The riser is placed in the flask right up against the pattern and sand is rammed around it to keep it in place.
The riser dimensions are 6" tall x 2-12" Top I.D. x 1-1/2" Bottom I.D. The wall is 1/2" thick all around. There is a step on the inside at the bottom to hold an optional foam filter.
After the metal cools the riser is cut from the part at the narrow bottom section.
It can be used with Aluminum, Zinc, Zamack, Brass, Bronze or Cast Iron.
Price is for a box of 6 Ea.