Step 1: Draw or Download a Design From Web, Then Laser Cut It
The attachment is the yin and yang symbol I modified from a picture from Vecteezy.
Or you can use any design you want.
Use .5'' thick wooden panel to laser cut the yin yang symbol.
Step 2: Make Silicone Mold
Use lego bricks to construct the walls of the container that you will use to cast the silicone mold.
Surround the wooden piece you got from the laser cutter with the lego container.
Put the vegetable oil on everything that will come into contact with the silicone rubber later. This will help in the de-molding process.
Mix the silicone rubber with the correct proportions according to the instructions on the product, and then pour the silicone rubber in to the mold. The silicone rubber used is a two part system and is linked in the "Materials Needed" section.
Cure for at least for 24 hours, then de-mold.
Step 3: Cast With Concrete
Mix the concrete according to the instruction on the package. Concrete can be purchased form stores like ACE Hardware and Home Depot. One recommended product is linked in the "Materials Needed" section. The cement should be mixed with enough water so that it resembles a fairly viscous liquid. Also, some cements may call for the use of aggregate, but his is unnecessary.
Make sure to rod the concrete mix (poke it with a stick-like object) in order to get rid of the air bubbles inside and scrape the extra concrete mix off the top of the mold.
DO NOT PUT CONCRETE DOWN DRAIN. Concrete cannot go down the drain as it will clog the pipes, any excess concrete should be thrown out.
You should allow the concrete to cure for a few days, particularly in a damp environment. If this is not available, cover the concrete with plastic wrap.
Once the part is cured, you can go back in and fill the yin yang hole with more concrete.
Adding mineral pigment to the concrete will allow you to use different colors in your concrete. Several options can be found here:
Step 4: Done
Sand the surface until it smoothed with sandpaper.
Now you can drop perfume or essential oil on top of the diffuser. The scent can last about a day or longer.