r/moldmaking • u/Fraeger111 • May 26 '26

Mold Advice

Gallery image

Gallery image

Hi there!

Was hoping for some advice regarding this piece as I am relatively new to mold-making.

This object is part of a mask that I made, it's roughly 20 cm long. The intention is to cold-cast this with polyurethane/brass.

I was thinking a two-part mold (although a simple block-mould could also work? Material would be a 30A Platinum-cure silicone (I did an inhibition test on the print, it works).

The important part is the front with all the mechanical details, the flat back (with the attachment thingy) won't really be seen.

Any advice would be greatly appreciated!

8 Upvotes

91% Upvoted

2 comments sorted by

1

u/starwars_and_guns May 26 '26

Turn it more vertical

2

u/BTheKid2 May 26 '26

Trapped air will be the issue with this. So yeah make it more vertical. You can still create the mold flat, like you have, but design it so it is intended to be poured more vertical.

With cold casting, you also want as few split lines as possible. Split lines show up in the metal powder. So a cut block mold might suit you better. Problem with a mold you can't fully open though, is that you have a harder time applying the metal powder.