so in practise for my torso model (more on that soon) I tried some trials with some simple materials to see the effect.

starting with a 3D printed key, the small key from The Legend of Zelda to be exact (which can be found here http://www.thingiverse.com/thing:237241) I then took a simple silicone block mould to start doing trials with cold casting.

if you don’t know, cold casting is the process of using metal powders in a resin base to create the effect of cast metal. it’s much easier to do than a solid metal piece and has particular advantages with larger pieces where weight is a factor (prop swords and the like). before I started I sought advice from the resin casting subreddit and from master prop maker volpinprops as to how to approach it.

I got a range of suggestions but as I didn’t have a pigment available at the time i chose to combine them, using a waterclear polyurethane resin mixed with the metal powders (one bronze one aluminium) as a base I then also coated the inside of the moulds with the metal powder before the pour.

now I don’t have access to a vacuum chamber at home so I couldnt remove air from either the silicone or the resin before moulding or casting respectively. however using a slow thin stream when pouring from the cup seemed to produce a good mould and cast as well. both were vibrated vigorously to remove bubbles from the surface and it worked rather well, with all the details from printing available. note if you are casting a 3D printed object, make sure to fill any holes you want to and sand flat any details you don’t want before you cast, much easier than having to modify multiple resin casts.

I find dragging your stirring stick across the surface lightly about halfway to setting time helps remove bubbles from the surface of your cast. I didn’t on the bronze and it shows badly on the underside, thankfully these are just tests.

for finishing I was planning to buff with steel wool and then metal polish, but it turns out my polish eats away the resin, whoops. but in any case it’s hard to get the printed lines to take a shine, it really needs a solid flat surface.

hope you enjoyed the first post, many more to come 🙂