Have you tried making the Glass Cups Part 1 Of 2: Cutting Jig project? Use the wooden jig you make in part 1 to hold a bottle steady as you score it with a rotary glass-cutting tool, then learn how to break it cleanly and put a professional glazing edge on the top rim of, a skill utilized by glaziers to make cut glass edges safe to handle.
Proper safety equipment is important while making the glass cups: work gloves, safety glasses, and a dust mask will protect you from the edge of the glass, as well as any dust you make while sanding or etching.
Your community may have specific instructions for how to deal with the sharp bottle tops and broken glass; research your local services and have a disposal plan in place before getting started.
Check out Fenestration Association of BC for more information on glazing careers. Special thanks to Zana Gordon for the inspiration and support for this project!
Explore Related Trades Careers: Glazier
Proper safety equipment is important while making the glass cups: work gloves, safety glasses, and a dust mask will protect you from the edge of the glass, as well as any dust you make while sanding or etching.
Your community may have specific instructions for how to deal with the sharp bottle tops and broken glass; research your local services and have a disposal plan in place before getting started.
Check out Fenestration Association of BC for more information on glazing careers. Special thanks to Zana Gordon for the inspiration and support for this project!
Explore Related Trades Careers: Glazier
Tools & Materials
Material List
- glass bottles (3+)
- wet-dry sandpaper, various grits 80-400+
- dish soap
- printed photo or design for etching step ~3" x 3"
- masking tape
Optional
Tool list
- safety glasses
- work gloves
- dust mask
- Glass Cup Cutting Jig from Part 1 of this project
- rotary glass cutting tool
- candle
- lighter or matches
- large jug or sink of ice water
- glass disposal bin
- paper towel or rag
- flat surface (table top or piece of laminate)
- electric rotary tool and etching bit
Optional
Procedure
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Prepare your ice water: fill a jug or sink halfway with cold water and add a handful of ice to it. Make sure it is deep enough to submerge your bottle below the cut line.
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Position your jig with the end piece braced against a wall or solid object, or secure it in a vise. Line a bottle up in the jig with the bottom against the end piece.
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With one hand (or both hands, if you’ve got a buddy to help you), push the bottle hard against the plywood end piece of the jig and rotate the bottle slowly around. With the other hand (or have your buddy to do this part), press the glass cutter firmly down into the side of the bottle. Press hard enough to hear the glass being scored by the cutting tool; rotate the bottle until you can see a continuous score line all the way around the bottle.
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If the bottom didn’t fall off in the water, remove it and wipe it gently with a rag or paper towel to clean away any soot. Inspect the score line: if it looks cracked through all along the score line, try gently twisting the bottle bottom and neck in opposite directions to pop the two pieces apart.
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If you can see that the glass hasn’t cracked all the way through, you can try repeating the heating and cooling steps once more. If it doesn’t work, place it in the glass disposal bin and try again with a different bottle; don’t put your original bottle back into the jig, as it is liable to break unpredictably if you try to score it again.
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Put on a dust mask, and make sure you are wearing gloves and safety glasses. Wet a piece of 80 grit wet-dry sandpaper, place it on a flat surface, and start sanding your sharp cup edge. Press gently, moving your cup in small circles (rotating it occasionally to make sure you sand it consistently around the lip).
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Repeat the flat and bevel sanding steps with increasing sandpaper grits, finishing with 400 grit paper (or finer, if you choose). Carefully inspect the cup’s top lip visually for sharp edges, then test it by running a piece of fruit or food along all the edges to make sure it won’t cut you. Take it to your instructor for a final inspection and approval.
Extension Challenges
- Make a matching set of 4 or 6 glasses as a customized gift, or personalize a set for friends, family, or housemates so everyone knows whose glass is whose.
- Cut protective stencils out of thick, sticky-backed vinyl, then stick them to your cup. Use a sand blasting setup or etching cream to etch designs. Anywhere not protected by the vinyl will be etched by the sand particles or chemicals. Wash your glass thoroughly before use..