The 20° Watering Can gives you precise control over the pouring of water. The parallel relationship between the spout and handle provides intuitive handling, the long and narrow spout allows water to be poured slowly and steadily, and a shallow angle of 20° in the handle makes it easy to carry.
Based on my initial sketches, I created a CAD model of the watering can in Fusion 360. After finalizing the design, I imported the model into Rhino, and designed the master to be cut out on a CNC router in high density polyurethane foam. The master would later be used to create a brush-on silicone mold, so I added a fence surrounding the design. I also added registration keys in the model so that the two halves of the silicone mold would self-align.
After the CNC cutting is completed, I noticed a few defects on the master, which I fixed using some wood filler. I then carefully sanded out the scallops left by the 1/4" ball end mill, and sealed the entire top surface using Smooth-on SuperSeal.
I used Smooth-On Rebound 25 for the brush-on silicone mold, and Smooth-On Plasti‑Paste II for the mother mold. One important thing to remember when making a brush-on silicone mold is to make each layer a different color from the previous one. This helps ensure uniform thickness throughout the entire mold and prevent weak spots.
I laser cut a 1/4" MDF sheet and placed it flat on the foam master right outside the fence for the silicone mold. This MDF piece would later become part of the mother mold, and would allow the two halves of the mother mold to be easily bolted together.
The material I used for slush casting is Smooth-On Smooth-Cast 65D. I calculated how much material I needed based on the volume information in Fusion 360, and mixed up small batches for casting.
