2 part molds and 1 part molds

[Tangyson]

I have looked at some books and seen some videos on making molds, And ive seen 2 part molds be done and 1 part molds, wich is better?, Or does the sculpt determine what type of mold is needed? 1 part molds seem to be easier to create than 2 part molds. Any info would be greatly appreciated.

[pinupstatue]

From experience doing one part mold is much easier no matter how complicated the sculpt is as long as you plan ahead on parting your molds. Also do diamond cut when parting the mold.

[Jesse321]

If the end result is that you're going to end up parting your mold, making a good 2 part mold is a better option.

[jayco35]

1 part molds are easier as no clay is required.
However it is not practical in all applications. Some sculpts have sharp undercuts or complex parts. These require a 2 part mold.
Should you plan on doing a large # of castings.
I recommend doing 2 part molds. I use both techniques all the time. Make sure if you do 1 part molds you invest in an Italian mold key knife.
This will cut and create a key at the same time. The compleat sculptor and other art supply store sell these. I highly recommend them.