Simple Bottle Cutting Jig

Cutting glass bottles can often be a frustrating task, especially if the score line on the bottle is not perfectly straight. For this reason, I will show you how to make a simple glass bottle cutting jig from scrap wood that is quite versatile when it comes to cutting different sized bottles. My design is intended to use a Kohler, 6 blade glass scoring tool without altering the tool itself.

For this project, the following tools and materials are needed:

-Three lengths of wood (dimensions are not very important)

-Two inch wood screws

-Drill bit approximately the same diameter as shaft on screw

-A glass scorer/cutter tool

-Radial Arm/Chop Saw

-Table Saw

-1/4 inch chisel and hammer

-Drill gun/screwdriver/drill press

The three lengths of wood I used were leftovers from previous projects. Their approximate dimensions are:

-12" x 4" (lengthwise support)

-17" x 6 1/2" (base for holding bottle)

-17" x 1 3/4" (edge for bottle to lean against)

Once the boards have been cut to size and sanded to clean up any burrs, you can start assembling the jig. I turned the base board and the piece that acts as an edge for the bottle to lean against upside down, supporting the overhang of the base board with a few scraps of wood and clamping the pieces to be joined to the edge of my workbench. I drilled and recessed four holes, driving four, 2-inch screws into the holes (the screw length might be a bit excessive, but I wanted to ensure it held together).

To attach the support at the end of the jig that the base of the bottle will eventually rest against, I turned the two pieces that were just attached so the edge support for the base had a corner nearly touching the edge of the horizontal support, and placed scraps of wood underneath to keep the angle. Placing the horizontal support on the opposite side of the base but maintaining the orientation of the board, I marked the approximate location of the edges of the board so I could drive screws into the end of the base. Moving the board back to the intended side of the base, I used a two-foot clamp to clamp the pieces together, and a one-foot clamp to clamp it to the workbench. Drilling and recessing holes, I drove three screws into the end of the base.

Now that the body of the jig is assembled, it is a good time to find where you want the scorer/cutter to lie. I placed mine at the end of the jig to accommodate larger bottles. I cut a piece of wood 6 1/2" long by 1" high for holding my scorer. As shown in the above images, I cut two notches in the wood: one for holding the metal end of the scorer (for cutting the side of bottles), one for holding the handle of the scorer (for cutting bottle necks). For the previously mentioned notch, I used a miter jig on my table saw to slowly trim small amounts of wood from the block, making sure the blade was set at a height that would allow for the scorer to protrude from the bottom of the block. I used my 1/4" chisel to knock a flat edge from the original curve made by the blade. Once the block could fit the hexagonal nut on the scorer in so the blade itself was just poking from the end of the jig, I used my drill press to drill a semi-circle in the wood, using a larger and then smaller bit to eventually get a parabola in the wood big enough for the handle to sit comfortably, again making sure the edge protruded over the block's side.

I then marked on the body of the jig where the scorer would protrude from the block intended to hold the scorer in place and drilled two screws into the wood to prevent the wood from being deformed from the force of the block against the jig. I drilled holes in the end of the block and into the jig for final mounting.

You will need a bottle you do not care much about for this. Beer/soda bottles work well for this, as they are inexpensive enough and easy to come by. Remove the block for holding the scorer and place the scorer in either the square notch (for cutting the side of the bottle) or the parabola notch (for cutting the neck); place the scorer and block back in place. Using scrap blocks of wood as spacers, adjust where the base of the bottle will rest against until the cutting blade is located where you want it. If you are cutting the neck of the bottle, you might need a block of wood against the edge of the jig and/or under the bottle to position it until the cutting blade just touches the bottle.

Once you are ready, apply pressure against the edge of the jig and toward the back of the bottle and slowly spin the bottle around. Since the bottle is in a jig, you should get an even score line around the bottle, regardless of how many times you rotate it.

After scoring, use near-boiling water and pour it over the scored line for upwards of one minute then rinse under cold water. There should be a definite 'crick' as the bottle cracks from the shock. If this does not happen, repeat the hot/cold shock until the top drops off. If the score is not deep enough, it may require you to go back to the jig and score more or a gentle tap against the side of the sink.

REMEMBER!! ALWAYS THINK SAFETY! Glass, if not handled properly may shatter in your hand while scoring a second time or during the hot/cold shock. If you injure yourself while doing this and not being cautious, you are the one at fault. Always remember to think before you act, and if possible, wear gloves and safety glasses on the off-chance that some catastrophic failure of the glass occurs.

This is a rather nifty jig. It costs very little, especially if the scrap wood is already on hand and can get very accurate cuts. It may also take a few cuts to get used to the handling and the feel of the jig, but once you get used to it, you can get very nice cuts. Enjoy the jig, experiment, and make some cool crafts with this! I am interested to see what you all come up with and how it works for you, so let me know.

Thank you and happy (glass) cutting!