How to Make Resin Coasters with Seashells and Sea Glass

This easy to follow tutorial will show you how to make resin coasters that preserve your seashell and sea glass collection from your latest beach vacation.

Do you like to collect sea shells and sea glass when you go to the beach? Why not preserve them in some resin and make cute coasters?

We recently went to South Carolina for a family vacation. The beach was beautiful and I thought I'd gather some shells for a craft when I returned home. I also added some sea glass that I had in my stash for color.

How to Make Seashell Coasters with Resin

The first time I made these I bought a translucent rubber resin (see above). That's not what I wanted at all and I ended up using a lot of my shells. Also, you can see that some of the shells are popping through the top so the second time I created a thin layer first.

Step 1 - Measure and Mix the Resin

The resin comes in two bottles. You need to mix them in a 1:1 ratio. I didn't have any small measuring cups and the product I bought did not supply them so I used a food scale.

First, you need to zero out the scale with your cup on it. Then pour a little of one of the resin bottles in. Then add the second resin bottle mixture carefully to double the amount on the scale.

Slowly mix the two together for 3 minutes. Then let it sit in the cup for 2 minutes to let the bubbles settle.

Step 2. Pour Mixture Into Molds

Pour the mix slowly and evenly into the silicone mold. You will see bubbles. Use a heat gun to remove as many of the bubbles as you can. If you don't have a heat gun you can try using a barbecue lighter. However, don't let the flame actually touch the resin or the mold.

Let this thin layer rest for 2 hours.

Step 3. Add Seashells and Sea Glass

Once the first thin layer has a chance to harden you can start setting your shells and glass gently on top. The idea is to have a buffer layer between the top of the coaster and the shells/glass which can be heavy and tend to sink.

Make sure that you place them upside-down as the mold is slightly rounded on the bottom making that the better side for the top.

Note: I didn't have too many left after my experiments but if I did I would have used more shells over-lapping slightly. However too many may cause them to sink and that wouldn't work well either.

Step 4. Mix the Remaining Resin

Next mix all the remaining resin together again, slowly, for 3 minutes. Let it rest for 2 minutes and slowly pour it over the two molds.

Step 5. Removing Bubbles

You will see more bubbles so carefully remove them with the heat gun. Also, they may appear for the next hour so check back every 5-10 minutes and remove any bubbles before the resin hardens.

Note: I still ended up with a few tiny bubbles but luckily since this is an ocean related craft it works.

Step 5. Removing the Coasters from the Mold

Wait at least 4 hours before checking to see if the resin is hard enough to remove from the molds. Once you remove them you should let them set overnight to finish curing.

You may find that the bottom has a ridge or a sharp edge. You can try to cut it off with scissors or use some fine grit sandpaper to remove it if you like.

You can also add little cushioned feet to the bottom. I had some extra from our kitchen cabinets and used them.

Here you can see how they look with a glass of water.

I think they make a nice paperweight or simple piece of decor too.

I think they are so pretty and a nice reminder of our family's trip to the beach.