Cutting Stained Glass With a Separating Ring Saw Blade
Taking a Circle From a Square
The current project I’m working on calls for a square of glass with a circular cutout in its center.
The easiest and most efficient way to cut large or irregular-shaped holes is by using a ring saw with a separating blade installed.
However, before I’m able to use the saw, there’s some prep work to be done to ensure it goes smoothly.
A circular cutout pattern drawn on to the glass it will be cut from
Preparing the Glass
First, I cut and grind the outer perimeter of my glass to fit my pattern (in this case, a perfect square). Once the circular cutout is removed, the piece will be much more fragile and prone to breaking if pressure is applied via cutting or grinding. Finalizing the outer perimeter of the piece makes it so I’ll have minimal work to do on it after using the saw, and thus minimal chance of an unwanted break.
The outer edges of the glass cut and ground to match the pattern
Applying glue over the pattern lines to keep them from washing away
Next, I go over my Sharpie-drawn pattern lines with a glue stick. Covering my pattern lines with a waterproof barrier is absolutely critical to ensuring that they stay put throughout the sawing to come.
Ring saws create heavy water flow across the glass surface, which can quickly wash away unprotected marker lines, and it’s a hassle to take apart a saw mid-cut to redraw.
After applying the glue, I wait about 5 minutes to make sure it's completely dry before moving on to the following steps.
Grinding the Initial Hole
Powerful as it may be, a separating ring saw blade can’t just stab through solid glass—it needs an entry point. To create one, I pick a point on my glass within the cutout section, hold that precise point on top of the ¼” bit of my grinder, and gently apply downward pressure until the bit grinds completely through to the surface.
Holding the glass on top of a 1/4" grinding bit to create an entry point
Throughout the process, I also hold a wet sponge on the underside of the glass against the grinder bit, periodically re-wetting it to maintain constant water flow.
I find this method to be the quickest way of creating entry points since I always have a grinder at the ready, but they can be created using any rotary tool with a diamond bit. Some artists prefer to use an electric drill or a Dremel tool.
The exact method of creating the entry point doesn’t matter as long as precaution is taken to ensure consistent water flow across the grinding surface.
This prevents inhalation of dangerous glass dust and also preserves the life of the grinding head.
Holding a wet sponge on the underside of the glass against the grinding bit to ensure consistent water flow
Cutting With the Saw Blade
A separating saw blade is installed just like a standard saw blade. The difference is that once it’s fitted into the saw, the separating blade can be pulled apart at a special joint, allowing glass to be slid onto the ring.
The separating blade opened at its joint, allowing glass to be maneuvered onto the ring
The separating blade closed at its joint, securing glass on the ring
After the blade is secured, the glass can be cut the same as with a standard saw blade—by slowly guiding the blade along the pattern lines. Once the cut is complete, the cutout can be removed and the saw blade unattached at its joint to free the remaining piece.
Using the ring saw blade to cut along pattern lines
The glass piece and the cutout separated into two individual pieces
Refining the Cut
I head back to the grinder to shape the rough perimeter of the circular cutout, this time using a 1” bit.
The Sharpie marks finally start to wear off at this point, so I have to pause periodically to redraw them.
The finished piece
Once the piece matches my pattern exactly, I’m finished!
Video Demo Using a Separating Ring Saw Blade to Cut Stained Glass
Watch the process!
A friendly reminder that I share details of my creation processes with the intent of empowering people with knowledge and techniques that may help them reach their full creative potential, not with the intent of enabling other artists to recreate my pieces. All of my designs are protected by copyright and are illegal to reproduce, reuse, or republish without my permission under any circumstances.
