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How to Set Shells in Resin

In this article, learn how to set shells in resin. Also, I show you how to cast seashells in resin for DIY projects such as coasters and tables.

Even if you don’t need to set shells in epoxy resin, the DIY tips I share can be applied to any epoxy resin project.

Here are some jump links to the main sections of this post to help you get the information you need quickly.
Video Tutorial
Tools and Material Used
Step-by-Step Instructions

Video Tutorial

There are several things which are difficult to fully explain with words and images, so be sure to check out the video tutorial below!

Tools and Material

Epoxy Resin for Deep Pours
Neutral Aqua Glow Powder
Mixing Containers
Wood Mixing Sticks
Mini Torch

Gather Seashells

For those of you not near a beach, I encourage you to purchase sea shells online or gather them during a beach vacation.

Luckily, my family and I live a few blocks from a beach and gather seashells while snorkeling, paddleboarding, and walking along the beach shore.

snorkeling in Destin, Florida
things to do in destin, florida
things to do in destin, florida
things to do in Destin, Florida
paddle boarding in Destin, Florida
dolphins while paddle boarding in Destin, Florida
sea turtle in Destin, Florida
manatee swimming in Destin, Florida

Determine Amount of Resin Needed

In order to set shells in resin, I need to fill the area halfway with resin. 
So, I figure out how much resin I need for the entire project and divide this number by 2.

Free Resin Calculator

To make this process simple, I included a link to a resin calculator at the bottom of this post.
So, be sure to download a copy before you go.

Best Resin for Setting Seashells

Seashells come in many shapes, sizes, and textures.  
Most importantly, the shape and porous surface of seashells may trap air and cause bubbles when set in resin.
As a result, I prefer to use deep pour epoxy because:

  • Thinner epoxy penetrates the porous surface and tiny holes better.  In turn, better penetration means less bubbles.
  • Deep pour epoxy cures slower which helps it form a stronger bond.
liquid glass 2.0 epoxy resin

Personally, I prefer my epoxy seashell projects with a few bubbles. 
They add a realistic underwater feature.  
However, too many bubbles and/or large bubbles are not good as it may cause issues over time.

Resin Formula for Gallons & Quarts

The formula I use to determine how much resin I need for a project in gallons:
(L*W*H) * .004329 = # of gallons needed
(L*W*H) * .017316 = # of quarts needed

First, I determine the volume in cubic inches by measuring the length, width, and height of the resin area.

Quick Tip: If the width of the area varies, take a measurement every 6 inches and average the numbers.
Volume = LxWxH

determine amount of resin needed

Next, I multiply this number by .004329 to get the number of gallons I need for the entire project.

In addition, I listed the formula to determine the number of quarts as well.
Gallons Needed = Volume * .004329
Quarts Needed = Volume * .017316

Then, divide this number by 2 to get the amount of resin needed to fill the area halfway.

Resin Calculator Example

For example, the area of my project is 47” long, 10” wide, and 1.5” high.  So, the volume in cubic inches is 705.
(47*10*1.5) * .004329 = ~3 gallons
(47*10*1.5) * .017316 = ~12 quarts

So, the first pour to set shells in resin needs to be 1.5 gallons (192 ounces).

I used deep pour epoxy for this project which requires a 2:1 mixing ratio. 
In turn, I mixed 128 ounces of part A and 64 ounces of part B.

Mix Epoxy Resin

As a quick tip, use 3 containers when mixing epoxy resin for accurate measurements and proper mixing.
In fact, most epoxy resin manufacturers recommend it.

Essentially, I use each container for a different purpose when mixing epoxy resin.

  • First Container:  Part A
  • Second Container:  Part B
  • Third Container:  Mix Part A and Part B.

My 5-gallon buckets were being used for a different project, so I used 6 small containers (2 groups of 3).

measure epoxy resin
mixing containers for epoxy
Mixing Liquid Glass 2.0 Epoxy Resin

Most epoxy looks cloudy at first.
However, it turns clear when properly mixed and ready to use.

Next, I added 4 ounces of glow powder to each 96 ounce container.
I use this step in the process to mix any additive to the epoxy such as pigment powder, dye, or glow powder.

epoxy resin glow powder
mix epoxy resin and glow powder

I thoroughly mixed the epoxy with a stir stick.

mix glow powder in epoxy

Pour Epoxy Resin

I poured the epoxy into the area and checked for leaks.

deep pour epoxy resin

Additionally, I poured resin in cracks to secure the wood.

fill wood crack with resin

Next, I removed the bubbles with a mini torch.

remove epoxy resin bubbles with mini torch

Allow Epoxy to Partially Cure

Before setting shells in resin, I allow the epoxy to cure about 30%.

Furthermore, some shells float to the surface if set in place before the epoxy pour. 
Or, shells sink to the bottom if set in uncured epoxy.

By allowing the epoxy to cure 30%, the shells slightly sink and form a bond. 
Additionally, I prefer to suspend the shells in the middle of the resin rather all the way on the bottom or top.

I check the epoxy every 12 hours by touching it with a stick on one end. 
Once the resin slightly adheres to the stick, I know it’s time to set seashells. 
A small string of resin follows the stick when removed.

Setting Shells in Resin

I chose the shells from my collection to set in resin.
Next, I placed the shells in the resin in a random pattern to resemble a beach or ocean shore.

how to set shells in resin
setting shells in resin

Once I placed the shells in the resin, they sank a small amount.

how to set shells in resin
how to set shells in resin
setting shells in resin

Then, I allowed the epoxy to cure a bit more before casting the shells in resin

Seal Shells with Resin

To prevent air bubbles, I recommend using a foam brush to apply resin to the exposed shells.

I find it easier to do this immediately after setting the shells in resin.
However, it works just as well to seal the shells before setting them in resin.

Some artists prefer to use fast setting epoxy to seal the shells beforehand.
Again, different strokes for different strokes. I encourage you to do whatever you feel most comfortable with.

Next, allow the resin to cure according to the manufacturer’s instructions and reapply if needed.

how to cast sea shells in resin

Keep in mind, I did not seal the shells in this project and had no issues with bubbles.

Resin Thumbprint Test

As a quick tip, I recommend to use the ‘Thumbprint Test’ before pouring additional layers of epoxy.

In other words, the epoxy should be soft enough to leave a thumb print. 
If the epoxy sticks to my thumb, I allow it to cure a bit more before embedding seashells in epoxy resin.  
However, if the epoxy is too hard for a thumbprint, I know I need to lightly sand the surface before applying a final coat.

Casting Seashells in Resin

First, I mixed the second half of resin (192 ounces) and poured the epoxy over the shells very slowly.  
I find I create air pockets if I pour the epoxy too quickly when embedding seashells.

casting seashells in epoxy resin
embedding shells in resin

Then, I monitored the epoxy for 30 minutes to remove any air bubbles with my mini torch.

Final Thoughts

After I learned how to set shells in resin, I began making beach inspired furniture, beach house decor, and resin ocean art using many of the same tips & techniques.

Ultimately, I hope this project inspires you to do the same.

Also, checkout the full seashell epoxy desk tutorial for the complete guide for this desk.

how to make a seashell resin table top

Related Posts:

Frequently Asked Questions

How do you put shells in epoxy resin?

The best way to put shells in epoxy resin is to set the shells in a thin layer of resin before it completely to set shells in resin

What to do with unwanted seashells?

One of the best ways to use unwanted seashells is to embed them in an epoxy river table.seashell epoxy table

Can you put seashells in resin?

Yes, you can put seashells in resin by completely embedding them in epoxy. Also, epoxy resin can preserve fragile seashells.embedding shells in resin