Introduction: Coffee Earrings (Made From Used Coffee Grounds)

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About: I'm a mechanical engineering student and a long-time tinkerer and maker. I've been working with 3D printers since 2012 and have been dabbling in various crafts for most of my life. I have at least some experie…

Do you want to wear coffee beans on your ears? Well, you've come to the right place!

These earrings are simple to make with some basic casting skills and use you used coffee grounds as color and filler for the epoxy.

Supplies

Materials:

  • Coffee Grounds (Used)
  • Several Full Coffee Beans
  • Casting Epoxy
  • Flexible Molding Material (Silicone or ComposiMold)
  • Mixing Cups (for epoxy and casting material)
  • A Cup to Make the Mold (the bottom of a soda can works really well)
  • Stir Sticks
  • Earring Studs

Tools:

  • Hot Glue Gun (do not use with heat curing molds like ComposiMold)
  • Exacto Knife (or another cutting tool)
  • Sand Paper (about 200 grit)
  • Oven
  • Baking Sheet and Parchment
  • Scale (optional)

Step 1: Mold Making

Select several coffee beans to cast.

Glue the smooth side of the coffee beans to the bottom of the cup (a soda can works well because the indent in the bottom will form a well in the mold to hold the access epoxy). If you are using a mold material that is hot while setting, like ComposiMold, do not use hot glue, use super glue. The heat from the molding material can cause the hot glue to release and the beans will float to the top. If you are using a molding material like silicone then hot glue is fine.

Once the glue is dried, prepare and pour the molding material into the cup and allow it to set. When pouring the molding material pour it in a thin stream onto the coffee bean to avoid bubbles.

When set, remove the cup from the mold (usually cutting the cup off is best) and carefully remove the coffee beans from the mold. If you are using a soda can please be careful of the sharp edges!

Step 2: Drying the Coffee Grounds

Preheat your oven to 200 F.

If you have access to a scale, weigh the coffee grounds before starting and note this weight.

Place a sheet of baking parchment onto a baking sheet and spread the coffee grounds out in a thin layer.

Place the sheet in the oven for an hour (If your grounds were wet or damp to start with you will want to leave them in half an hour to an hour longer. Because of the low temperature, you can't dry them too long so if you're unsure longer is better).

After the hour, weigh the coffee grounds again, they should have lost about half of their weight. If they have not, return them to the oven and weigh again. Repeat until they stop losing weight. I have found that coffee grounds that are relatively dry to start with will lose about half their weight during this process.

If you do not have a scale, simply dry the grounds for an hour and a half. This should be more than enough to get them very dry.

Allow the ground to cool and store in an airtight ziplock bag, ideally, with all the air removed.

Step 3: Cast!

OK! Its time to cast!

If you want, cover your work surfaces to protect them from epoxy spillage.

Mix the epoxy per the instructions. The most important tip for using epoxy is to mix it thoroughly, scrape the sides and mix for at least 2 full minutes.

Add the dry coffee grounds to the epoxy. I usually add a little at a time until the consistency of the epoxy is thick but still flows (like thick honey).

Pour the mixed epoxy into the mold in a thin, long stream. Now we need to get the bubbles out. If you have access to a vacuum chamber, that is the best. I use my jigsaw (without a blade) to vibrate the mold by holding it upsidedown and holding the mold on the table of the saw. An orbital or detail sander (without a sanding disk) would work equally well. If you don't have access to any similar power tools, try to find some way of vibrating the mold to remove the bubbles or hit it on the table several times to try to get the bubbles to float to the top.

Allow to set for the time specified by the epoxy's instructions. Make sure that the environment is within the specified temperature requirements, generally, a warmer space is better.

Step 4: Attach the Studs

When the epoxy is set, remove the castings from the mold. Sometimes they will come out with the extra epoxy and sometimes they will break off and you will have to remove them from the mold individually.

If the molded coffee beans did not break off of the extra epoxy when demolding break them off now.

Now you should have the beans with some extra material where the opening of the mold was.

Lay a sheet of 200 grit sandpaper on a flat surface an hold a bean as flat a possible while sanding off the extra material. When you are done there should be a small flat area on the smooth side of the bean.

I used super glue to attach the studs, epoxy would also provide a good bond. Apply your glue to the stud or the flat surface of the bean and put the stud in place. Allow to fully dry before handling.

Congratulations! Your earrings are done. Now get out there and show your love of coffee to the world!

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