There’s always way to switch things up when creating! I love budget friendly design options so using stones is perfect. Here’s my tutorial of how to make Glass Mosaics on Rocks… ’cause I love rocks.

Outdoor Mosaic Options:

The charm of mosaics lends itself nicely to be used outdoors. This method does not use a grinder but only a glass cutter and some tile nippers therefore the pieces are somewhat rustic in style. That works well with using natural elements to work on.

Why Use Rocks?

Well, one reason is that I LOVE rocks! Even though I have not made them I really appreciate the textures and nuance details that they bring to a design. It’s funny how people know me and when they want to give away their rocks or stones ask if I want them. This is flagstone that used to cover a porch. I have read that it’s not advisable to take rocks from nature. Many garden centres do sell various types of stone as well.

The shape and even the extra ‘bump’ gave me some ideas…

Using scrap glass:

As you know from this I have a fair bit of scrap glass. When I am filling certain shapes I look through to see if a piece already fits the shape I need; it is somewhat like jigsaw puzzling. I may be making quite a bit with this glass!

Start your Mosaic design:

One challenge of working on this rock substrate is how to get the design onto the rock surface. As an illustrator (for more than 20 years) I have come across this issue so many times on all kinds of media. Sure, you can draw directly on the surface (with a pencil) or use a projection method. There is an app that allow you to use your phone (or ipad) to see the image while drawing it onto the surface of the rock or other.

There is also the option to use some sort of transfer paper (like a carbon paper) but I find those troublesome since the stone has texture. If you have a drawing (tracing) on paper you can also cut it out to outline the shape. A grid drawing system also works but might seem tedious for such a simple design….

The Adhesive for Rock:

Since this is natural stone it has some great textural ability to adhere to. I am using Versabond Professional Thinset Mortar as the ‘glue’. (follow manufacturer’s instructions) I mix it it to a about a peanut butter consistency and let it sit for a few minutes, mix again and then put it into small plastic bags. Any bags can work (up-cycle), just make sure they are sealed or tied well.

Putting the grout/mortar in a bag gives you more working time as the polymer is less exposed to air. This method also keeps it very controllable and clean. Small areas of this adhesive can be applied accurately when the corner of bag is snipped.

What tools do I need?

One reason I like this mosaic art method is that I am not using a lot of tools & easy setup. Using the odd shapes of the scraps lets me see if any just fit or a bit of nipping with the glass nippers to adjust the shape. There’s no reason some other small rocks could not be added as well (oh, gee some new ideas just popped in my head).

Working bit-by-bit across the surface with a small amount of grout was pretty easy. Use a permanent marker to draw the shape needed to cut. Later on this can be rubbed off with fine steel wool. Here’s a tip: whenever I add a material into a dry porous surface I like to dampen it so that the moisture is not instantly ‘sucked’ out of the addition. This is quite important when working with concrete so I feel similar benefit here.

Adding Piece by Piece:

The Versabond has Polymer added as well so do not add extra water. If any areas need some smoothing a small brush works nicely.

Compared to true stained-glass mosaics this may seem quite primitive, but since it is a natural stone it seems quite an appropriate addition. If any grout gets away from you a damp sponge will clean it off. The grey colour of the Versabond actually perfectly matched the stone. A spatula can also apply the thinset to make sure edges have good coverage. The glass should be imbedded at least 1/3 of it’s depth.

I hesitate to use any type of accelerant as there is some Portland cement component in the mix, and they cure stronger when they have proper reaction to the moisture. That is why this mix has such a hard finish. Any sharp edges can be sanded of using the emery cloth.