Would 4 part mold solve this challenge? Answered
Great lesson and learned a lot from your class. This is my reason for taking the class, I have a need to mass reproduce this in refractory material from made from plaster. Your input would be appreciated. My thoughts are these:
1- two part silicone mold for outer shape , split top to bottom, front to back. Frame made of millimine covered board. 2-additional two center parts from silicone for the upper (or of hard polymorph material) and lower portion - divided at the center of the center circle. If using polymorph, I would make a key at the union to orient the lower silicone piece to alignment them and perhaps a key in the bottom board to orient the bottom silicone piece. Stabilization of these two independent pieces could be achieved by a bolt through their centers and bottom of wood mold form and firmly tightened to place and retained by a butterfly bolt and washer. 3- refractory pour being made from the top.
My positive needs to be finished a little better before I'm ready and I am also wondering what type of sealer or surface application should be used if a glossy finish to the mold surface is desired? I tried a watered down wood glue solution (PVA) but it doesn't seem to dry well enough and peels easily. I would also like to retrieve the piece in as good a condition as possible for later changes and improvements. Thanks for your advice and that of others with helpful input.
Thanks 4 of 4 thumbs up!
PS. There are two other interlocking parts not shown which complete the casting. I believe I can accomplish those molds easily enough and plan on casting all 3 parts from the same mix of refractory so shrinkage/expansion are the same for all parts.
PPS. Also I would like to know, if you know, of an online service which will recreate my logo from 3D printing such as you had done for the doughnut two part mold lesson.