School Themed Epoxy Resin Coasters With Crayons

This is a simple epoxy project, albeit a bit time consuming and costly. School themed coasters can be made by or for children or given to teachers as tokens of appreciation. 

You will need clear epoxy resin for casting, silicone mold for coasters (minimum 9cm in diameter to fit regular crayons), crayons, pencil stubs and 'fillers'.

'Fillers' can be paperclips, small erasers, pencil sharpeners, thumbtacks, glitter and small beads. Anything colorful. I didn't have any beads, so I used sewing pins with colorful heads. 

You will also need small, transparent disposable cups, stirring sticks, gloves for mixing the resin and a hair drier or a heat gun.

My coaster mold is home made and 11cm in diameter.

Each resin is different, different manufacturers offer different products. Some resins cure in 24 hours and some take as long as 3 days. Certain resins, once mixed, leave you with a lot of air bubbles, while other resins are less prone to bubbles. There are two ways to keep the coaster relatively bubble-free.

1. Pour the resin slowly, in a thin steam and from a distance. Just raise your cup 1-2 feet in the air and pour slowly.
2. When resin is freshly poured, use a heat gun to run hot air throughout the top to disperse any bubbles. Sometimes, if there are just a few air bubbles, you can use a match or a lighter, or a torch, but be careful, because open flame can burn the resin and you will end up with a visible yellow/brown burned spot.

Before you start adding any objects, you have to pour a small amount of epoxy into the mold (1-2mm thick) and let it set for a few hours. Heat the resin with a heat gun to disperse any bubbles.

No need to wait until it sets and cures fully, that can take up to 3 days. Just wait until it's no longer liquid, just soft and gummy. 

The second layer of epoxy is when you can add crayons, pencils and some 'fillers'.

Don't add all 'fillers' straight away, to create depth and a more visually attractive coaster we will add fillers in a few layers so it's more dimensional. 

Mix a small batch of epoxy and pour it into the mould. Pour only enough to cover half the crayon. Place your crayons and fillers in the mould and move them around with a toothpick until they are placed where you want them to be. 

Let the resin set for a few hours until it's no longer liquid. 

The third layer is again a small batch where you only add enough resin to cover the crayons fully and add more fillers to the bald spots. 

Depending on the thickness of the mold, this might be your final layer, or you might have to (or want to) add one more layer of 'fillers'.

If you want your coasters to have a black backdrop, you will have to add a black colored resin in the end, so leave 2-3mm space at the top. Once the last clear layer is set, you can add a final layer of black resin.

Or you can paint the back of the coaster with a black paint. I made mine black by gluing a black felt onto the back to protect the table. 

My coaster came out quite shiny and I felt no need to sand it, but if you want, you can polish it until it shines. It takes ages and requires you to sand with a variety of sanding pads that go all the way to 8 000 or 10 000 grit. Sanding is not necessary if you have a good quality silicone mold.

Paint the back of the coaster if you want, or leave it transparent. Add felt to the back or clear silicone protectors.