Fully printed system to make plaster moulds. This produces a 3-part mould to cast round ornaments with an spherical design.
This print has been scaled to 112% to account for clay shrinkage, which should give a final ornament size of 6.5cm diameter with most casting slips. If you want it smaller/larger than 6.5cm, scale every piece of the print.
- With any fully 3D printed mould, you’ll benefit from using a release agent on the base plate surface. I use a generic mouldmaker’s soap, but any product designed for plaster release should be fine.
- It needs around 375ml of plaster, and you can calculate the weight of water and plaster needed with this tool: Plaster Calculator
- You can get a much better cast surface, even if your plaster mix is full of air bubbles, by using a paintbrush to dislodge any trapped air from the surface. I would suggest that you pour plaster until the ornament surface is covered but it isn’t completely full, then get a relatively small paintbrush and move it around in the plaster so that you’re brushing all of the details on the base plate surface. This will dislodge air bubbles, and once dislodged they’ll float upwards. Once you’ve finished this, pour in the rest of the plaster. If you manage to avoid adding more air as you do it (just brush gently), you’ll eventually remove all the bubbles from the surface and get a perfect cast.
- The plaster will take a little bit of wiggling before it will release from the print. Start at the corners of the bottom end, and work your way up to the end with the pouring spout. If you have an air compressor, blowing air between the two is a great way to release them.
Old Forge Creations
