Stepping Stones: Mosaic Stained Glass Crafts

The Indirect Method is the preferred choice of artisans for creating highly detailed stained glass mosaics with smooth, even top surfaces. This is accomplished by placing the tesserae (Stained Glass Cobbles) onto clear contact paper which is then placed into the pouring mold. A concrete mixture is then poured over the glass to form the stepping stone. Any thickness variations in the glass is resolved using this process.

Intricate designs can easily be prepared ahead of pouring without any time constraints. The clear contact paper placed over the artists rendering allows the glass to be set to the design perimeters. Any changes can be easily made prior to pouring the cement.

In this demonstration white sanded grout was used in the first pouring followed by a layer of gray cement mortar to give the stone added strength. The white grout enhanced the colors of the Stained Glass Cobbles making them vibrant and rich.

The material list, a complete photo tutorial and written instructions on how to make the mosaic stepping stone follows.

A Paper Pattern Design cut to fit pouring mold
Stained Glass Cobbles
Clear Contact Paper (shelving)
Scissors
Mold (we used 12" round mold)
Mold release agent such as vegetable oil
Sanded Grout with polymer (we used white)
QuikCrete Mortar
Water
Mixing buckets
Measuring cups (dry and liquid)
Gloves
Mask
Garden Trowel
Screwdriver or Rubber Mallet
Paper Towels

Step 1.Choose Your Mold / Create Your Design

There are plenty of stepping stone molds to choose from, most costing just a few dollars Molds are usually made of plastic, available in a variety of shapes and sizes and they can be used multiple times. Amazon has a wonderful selection you may want to check out. For our stone we used a 12" circular mold.
Once you have chosen your mold make a paper template to fit. Sketch your design onto the template.

Step 2. Set-up Your Stained Glass Cobbles / Prepare Your Mold

Once you're happy with your design set up your glass colors.
Lightly spray your mold with a vegetable oil (or brush it on) to keep the cement from sticking.
Using your paper template cut the same size shape out of the clear contact paper.
Place your paper template inside your mold design facing up.
Peel the cover paper away from the sticky contact paper then place the clear contact sheet sticky side up on top of your paper template. If needed you can use a bit of scotch tape to keep the contact paper in place.
Layout your glass directly on the contact paper pressing each piece firmly into place.

Step 3. Prepare For Pouring / Set-up Your Workspace

Pick a place where there is good ventilation and is suitable for working with cement. Outside on a nice day or in your garage should be ideal. Set up a level work table covered with newspapers or a plastic tarp. Place your stepping stone mold along with all of your needed tools, water, grout and cement mortar close by. I always like to have a bucket of water nearby to clean my tools as needed.
Make sure to have your latex gloves, protective dust mask and eye-wear ready to use.

Step 4. Mix Your Grout

Put on your latex gloves, dusk mask and safety glasses. Measure out 4 cups dry white sanded grout into a large bucket. Add 3/4 cup of water, having more water available to add as needed. Using a trowel, thoroughly mix the grout with the water until it is like thick peanut butter. If the mix is too dry add a small amount of water until it is of the desired consistency. If is too runny add more dry grout. Make sure the slurry is thoroughly mixed before pouring.

Step 5. Pour Your First Layer

Gently cover your glass tesserae with the grout slurry spreading it with your trowel until the glass is evenly coated. Gently tap the sides of the filled mold with the handle of your screwdriver for at least 30 seconds to help burp the grout slurry of any air bubbles. This will also help level out the wet cement. Let the grout sit undisturbed for 15 minutes while preparing for your second pour of cement mortar.
Clean your bucket and trowel of all excess grout.
Note: Make sure you "Gently" burp the slurry...don't shake the mold or pound on the sides, this can cause the glass to move allowing the grout to seep between the glass and the contact paper.

Step 6. Mix Your Cement Mortar

Put on your dusk mask, latex gloves and safety glasses. Measure out 8 cups of dry cement mortar into a large bucket. Add 1 1/2 cups of water having more water available to add as needed. Using a trowel, thoroughly mix the dry mortar with the water until it is like thick peanut butter. If the mix is too dry add a small amount of water until it is of the desired consistency. If is too runny add dry mortar. Make sure the slurry is thoroughly mixed before pouring. See mixing tips for additional instructions.

Step 7. Pour Your Second Layer

Gently pour the cement mortar on top of the white grout spreading it evenly with your trowel. With the edge of your trowel smooth the surface to a nice even level. The total time you spend on mixing, pouring and smoothing should be no more than 5 minutes. Gently tap the sides of the filled mold with the handle of your screwdriver for at least 30 seconds to help burp the cement slurry of any air bubbles. This will also help level out the wet cement. Let it sit undisturbed overnight. Once the stone has hardened invert the mold and gently press on the back of the mold to release the stone.

Step 8. Dry With Care.

Elevate the stone on wood dowels or pencils to maximize air circulation for even drying. For the first 24 hours after making your stone let it sit undisturbed. This is when it is the weakest. The following day you can move it indoors where it will need to fully cure for a couple more weeks before it can go outside.

Step 9. Clean Up.

Be sure to clean off the trowel and plastic tubs as soon as you're finished with them. Any excess mortar discard in a trash bag. Tools can be easily cleaned outdoors using a garden hose or wash them in a bucket of water. Once the cement hardens it will be difficult to remove. Don't clean them in your house sinks....cement can clog up your drain lines!

There is an easy way to calculate the amount of dry cement you will need to make a stepping stone:
1. Fill your mold with water up to the level you would fill with your cement slurry.
2. Measure the amount of water you used in cups (8 oz. per cup)
3. Take the number of cups and multiply it by 1.25 to find how much dry cement will be needed.

Note: It is always better to make a little more than not to have enough.

For suggested amounts of dry cement for specific size molds go to: The Garden Stepping Stones Tutorial

There are a number of cement colors you can choose from. For more information go to: Make Stepping Stones the Easy Way

Many stepping stone artisans prefer to "seal" their finished pieces to protect them from staining and preventing the grout from taking on additional moisture. There are several different brands of cement sealants available for use on homemade stepping stones. Choose one that is waterproof and dries clear.
Your stepping stone needs to have cured for a month before applying a sealant. Follow the manufacturers directions as to how to apply.