Skip to Content

Step-by-Step: Making Sea Glass With & Without Rock Tumbler

As an Amazon Associate, I earn from qualifying purchases with no additional costs for you.

Naturally, sea glass is made by the rolling, churning motion of the ocean as it tumbles broken glass into beautiful, frosty sea glass or mermaid tears. Many people comb beaches worldwide, collecting green, white, blue, yellow, brown, and even purple and red pieces of sea glass.

One can replicate the process by which sea glass forms and create your own sea glass from recycled glass. Tumble 0.5-1.5-inch pieces of broken glass in a rock tumbler for 4-5 days with 2 tablespoons of medium grit or beach sand. One can also use a cement mixer if you do not have a rock tumbler.

By making your own sea glass, you can have much more significant quantities to craft with or use in the garden. There are many striking ways to use sea glass for home décor, especially in beach houses. This is a comprehensive guide to DIY sea glass.

How to Make Sea Glass With and Without Rock Tumbler? Simple Guide
How to Make Sea Glass With and Without Rock Tumbler? Simple Guide

If you are interested in checking out the best rock tumblers for tumbling sea glass you can find them by clicking here (Amazon link).

Tumbling Glass is Different from Tumbling Rock

There are some key differences between rock and glass that we must keep in mind when using a rock tumbler to create sea glass. Tumbling glass is not as straightforward as tumbling rock. 

Firstly, glass is lower down on the Mohs Hardness Scale than rocks like a jasper, quartz, and agate. Glass is softer, with a hardness between 4 and 6. This means that you do not have to tumble glass for as long as you would tumble rocks, and it is not necessary to tumble with coarse silicon carbide grit first. 

Secondly, glass is less resistant to breaking and chipping in a rock tumbler. It is not as tough as many rocks, and therefore, it is crucial to fill the tumbler barrel with the right amount of material. Underfilling it will result in the glass breaking as pieces crash together. 

It is also essential to have a range of particle sizes in the tumbler. Smaller pieces of glass will fill the spaces between large pieces, reducing the shock impact when tumbling. This prevents chipping and breaking.

If you do not have enough glass to fill the tumbler to two-thirds of the way full, add ceramic pellets to the tumbler barrel. This will cushion the glass pieces from crashing and breaking against each other, and the pellets will distribute the grinding powder more evenly, increasing the amount of abrasion. 

Make Sea Glass Using a Rock Tumbler

You will need the following materials and equipment:

  • Rotary rock tumbler. It is worthwhile using a good-quality rock tumbler. Many beginners or toy rock tumblers rotate at high speeds – around 90 barrel revolutions per minute (brpm). This will fracture and damage the glass. Look for a rock tumbler that has adjustable speed control. You want to run it at 20 to 50 brpm. 
  • Medium grit silicon carbide. If you would like frosted sea glass, use only medium grit. If you would like polished glass pieces that look like gems, use fine grit and polishing powder. 
  • Filler material. It is best to fill a rock tumbler two-thirds of the way full. If you do not have enough glass to fill it to this level, add ceramic or plastic pellets. These will fill the spaces between glass pieces, preventing them from crashing against each other, chipping, and breaking. Having filler material helps the abrasion process by carrying grit to larger pieces of glass.
  • Glass. Look for thick glass, like Coca-Cola bottles or vintage wine bottles. Avoid using glass that is too thin. Landscape glass, available from gardening and hardware or home improvement stores, works well. The ideal size of glass pieces is between 0.5 inches and 1.5 inches. Curved pieces do not work very well. 
  • Hammer and towel. To safely break the glass. 
  • Tile nippers (optional). In case you would like to shape any pieces of glass more accurately.

Follow these easy steps to transform recycled glass into beautiful sea glass:

  1. Wrap the glass you want to use in a towel, put it down on a hard surface, and, using a hammer, break the glass.
  2. Set up the rock tumbler, ensuring it is clean, and load it with glass and filler material to two-thirds of the way full. 
  3. Add two tablespoons of medium grit and water until all the glass is just submerged. 
  4. Close the tumbler and run it for 4 to 5 days.
  5. To check the glass, switch off the tumbler, open the barrel and check if the glass is rounded and frosted to your satisfaction.
  6. If you want to modify the shape of some pieces, pick them out of the tumbler and trim them using tile nippers.
  7. If you are happy with your sea glass’ luster and shape, empty the tumbler, rinse the glass, dry it, and enjoy!
  8. If you would like a more frosted finish, keep tumbling the glass for another two days.
  9. To create brightly polished sea glass, repeat the tumbling process with fine-grit silicon carbide. Run the tumbler for 7 days.
  10. Clean out the tumbler thoroughly and repeat the tumbling process with polishing powder (aluminum oxide powder works well). Run the tumbler for 7 more days to achieve shiny, glossy stones. 
  11. An extra step, called burnishing, can be done to add extra shine to the sea glass. Burnishing gets the polishing powder or micro-particles of glass out of tiny crevices. Place the sea glass in a clean tumbler barrel along with half a tablespoon of grated plain soap and fill it up with water. 
  12. Run the tumbler for 3 to 4 hours.
  13. Empty the rock tumbler and admire your shiny sea glass gems.

Using Beach Sand Instead of Grit to Tumble Glass

Many people tumble glass with beach sand instead of silicon carbide grit to simulate natural sea glass better. Because beach sand is generally not as sharp and coarse, you may need to let the tumbler run for a few more days to achieve an even, frosty result. 

An advantage of using beach sand is that it is much more environmentally friendly than other commercial abrasives. It is also free.

TIP: Using sand is a great option for tumbling. But are you really able to tumble rocks using the sand? Find out everything you need to know about using sand for tumbling in the article below:
Can You Tumble Rocks with Sand? Everything You Need to Know

Make Sea Glass Without Using a Tumbler

Many DIY sea glass tutorials online allege you can make sea glass by shaking broken glass, water, and sand together in a mason jar. This is unrealistic, at best. 

Making sea glass in a rock tumbler takes a long time. The machine turns at a constant speed and power for hours to days, grinding away at the edges of the glass. One would not be able to replicate this kind of action using your arm. 

One way to make sea glass without a rock tumbler is by using a cement mixer. It is a noisy endeavor, but the results are totally worthwhile. 

Gather the following materials and supplies:

  • A cement mixer.
  • 5 liters of water.
  • A pound of beach or play sand.
  • 1-2 kg recycled glass.
  • A hammer and towel.
  • Large buckets and a colander

Follow these simple steps to make your own sea glass:

  1. Add the glass, sand, and water to the cement mixer.
  2. Switch the machine on and let it do its noisy business for 4 hours.
  3. Check on the glass to see the results. You can let the cement mixer run for another 2-4 hours until the glass reaches your desired finish. 
  4. Tip the glass out of the mixer and rinse it with water over a large bucket. Do not do this over a sink! The sand will clog your pipes. 
  5. Use a colander to strain out the glass.
  6. Admire your new sea glass treasures. 

Invest in a Hobby Rock Tumbler

Cement mixers are large, noisy, and maybe impractical for some people. There are many great beginner or hobby rock tumblers available online. They are really affordable, starting from around $40

It is worthwhile to make this small investment so that you can make all the sea glass your heart desires whenever you need it!

TIP: Using a rock tumbler is much easier than using a cement mixer. If you are interested in buying a rock tumbler check out the best rock tumblers for beginners and hobbyists in the article below:
Best Rock Tumblers in 2021: Beginner and Hobbyist Options

Best Types of Glass to Use to Make Sea Glass

When it comes to collecting glass to make your own sea glass, remember: the thicker, the better. These are some of the best-recycled glasses to use for making sea glass:

  • Sparkling wine bottles. Due to the high pressure of the bubbles, sparkling wine bottles have to be much thicker than regular wine bottles. The bottoms of the bottles can make gorgeous, tumbled pieces.
  • Vintage vases and glass ashtrays. Hunt for items at local charity shops and garage sales.
  • Some Grappa and Prosecco bottles are a brilliant, deep blue and they are usually thick enough to make beautiful sea glass pieces.
  • Perrier bottles make beautiful light green sea glass pieces.
  • Whiskey bottles are also a good choice. They usually have a thick base, and many have interesting designs. 

Look for recycled glass in colors like red, purple, yellow, or orange. Finding sea glass in colors other than white, green, and brown on the beach is pretty rare, so you can make your own. 

BTW: Do you want to know more about rock and mineral identification? The books listed below are the best ones you can find on the internet (Amazon links):

DIY Projects Using Sea Glass

There are so many different crafts and DIY projects one can do with sea glass. It is the perfect material for a beach house décor.

Here are just a few ideas for projects you can do with sea glass:

  • Home décor. Add sea glass to the bottoms of flower vases or glass bowls. Mosaic sea glass onto glass to make beautiful window hangings. 
  • Jewelry. Silver wire can be twisted and wrapped around the sea glass to make rings, bracelets, and pendants. It is easy to drill holes through sea glass using a Dremel and a diamond-tipped bit. One can easily make beautiful beads, pendants, or earrings. 
  • Hanging light fixtures. By drilling holes through pieces of sea glass and hanging them using a transparent fishing gut, one can create a beautiful, nautical chandelier. 

Use Sea Glass in the Garden

Sea glass garden paths or beds have an ethereal, magical quality. The frosty glass contrasts beautifully with bright green leaves and colorful flowers, and having it covering the soil will reduce water loss from the soil. Sea glass adds to a garden in both form and function.

TIP: Did you know you can dye rocks with food coloring? Dyeing your rocks is another great DIY activity you can do with your family or friends. Especially dyed garden rocks are really beautiful. Find out more on how to dye your rocks with food coloring in the article below:
How to Dye Rocks with Food Coloring? Follow These 5 Steps

Creating a Sea Glass Effect on Larger Pieces of Glass

To create a sand-blasted, sea glass effect on window panes or glass items that would break in a tumbler, like vases or bottles, one can use sea glass spray paint

Although this is not the real thing, one can closely replicate the color and finish of sea glass using spray paint. It is semi-translucent with a smooth, powdery finish. There are many different ones available, but it is recommended to use a well-known brand like Rust-Oleum or Krylon

Sea glass spray paint is great for making small decor details, like sea glass medicine bottles or vases from pretty gin bottles. One can also use this spray paint for more functional things, like frosting a bathroom window for privacy.


Combining the beach to collect sea glass is a relaxing, fun way to spend a day. However, you definitely will not find enough naturally-made sea glass to adorn your garden beds with a layer of sea glass or create a sea glass garden path.

For projects that require a lot of sea glass, it is best to make your own. Fortunately, making your own sea glass from recycled glass is simple. It just takes time.

You will need either a rotating rock tumbler or a cement mixer. Break glass into pieces between 0.5 inches to 1.5 inches in size. Add them to the tumbler or mixer, along with water and sand or medium grit silicon carbide, and wait for the machine to do its work.

In a rock tumbler, it takes between 4 and 6 days to get a nice, frosted finish, but in a cement mixer, it can take 6 to 8 hours

The best types of glass to use to make sea glasses are champagne or sparkling wine bottles, whiskey, prosecco or grappa bottles, or vintage glass ashtrays and vases. Making sea glass is a wonderful way to recycle glass.

TIP: Finding a sea glass on the beach is not so demanding. But what about other rocks? Do you know what are other common rocks you can find on the beach? Find out more in the article below:
25 Most Common Rocks on the Beach: How & Where to Find Them?