Step 1 (CLick the image to continue reading & for a larger image)

This is slightly different than the "top to bottom" pouring mold. It will still be poured from the top, but parting line will be vertical instead of horizontal. This mold is designed to be poured along the parting line. The sprue is the center &

Step 2

The "trench" around the three sides will help keep the resin form oozing out the sides. The other impression in the clay are "registration keys". These keys and the trench will make sure that the mold halves line up each time I make a

Step 3

This old sterilizing pot has become a casting chamber. With the clear cover, I can pull a high vacuum on the mixed RTV to get the air out of the solution. The bucket needs to be at least 3 times the volume of the RTV you are mixing. When placed under vacu

Step 4

Here is the first side filled with RTV. There is a second mold being made simultaneously just to the right.

Step 5

The second side has been poured and cured. Here the smaller mold has been unboxed and you can see the two halves

Step 6

Here the box has been removed, and the two halves have been separated. Use a sharp X-acto blade to cut apart any small areas that were missed by the mold release and stick together. Be sure to cut close to one side and not the center of the stretched atta

Step 7

I place some foam core on each side of the mold and then rubberband it together. The foamcore prevents the rubberbands from "gapping" the sides. The extra piece of foamcore on the center applies pressure to the center of the mold to reduce flash

Step 8

Measure and pour the Resin. Polyurethane is a two part, one to one mix. These three molds took less than an ounce of resin. The funnel is filled till the resin appears in the deairing holes on each side. I continue to add resin till the funnel is full. Th

Step 8

The parts are solid in about 15 minutes, but they are still soft. I leave them until the excess resin in the cup, or a single sided mold gets pretty stiff. Once this occurs The rubberbands can be removed and the mold opened up.

Step 10

Here is the mold opened up and the finish parts are ready to be removed.