Introduction
I designed this glass bottle scoring device as a gift to a friend who wanted a way to recycle glass jars into cups and vases. This journey started when we attempted the popular online method of wrapping a glass jar in acetone soaked string, igniting it, and thermally shocking the glass in ice water but we were disappointed with the results. It was difficult to get the glass to break at all and when it did, the fracture was not consistent or usable.
After some research, my friend bought a pen style glass scorer. This device is essentially a handle with threads to accept a chunk of metal which has a very small piece of tungsten carbide pressed or glued into it. The carbide is significantly harder than the glass and thus etches a groove when it is dragged on glass. The score line makes a weak path that the glass acts as a point of failure when stress is applied by bending the sheet with pillars. Using this technique, precise glass shapes (like those used in stained glass) can be made by hand from glass sheets.
However, we couldn’t find success with these pen style scorers with bottle glass. Cutting sheet glass is easier since the score line extends to the edges of the glass. The intersections of the score with the edge of glass make points for the crack in glass to start propagating from. When working with a circular score on a jar, the score makes a closed path longitudinally around the jar, meaning there is no end point for crack propagation to start. This means higher stress is necessary to initiate crack propagation and the higher stress leads to higher energy breaks which happen all at once making it difficult to get cracks which follow the score line. All in all, this means the score needs to be perfect which wasn’t possible by hand.
It was clear a device was needed which constrained the bottle or cutter so the score line would be straight and consistent. I researched what was available for purchase and decided to design my own device using the same concepts.
Functionality and Components
Details coming soon!
Carbide Bracket
Horizontal Jar Backstop
Vertical Spring Support
Assembly Instructions
This project was given as a gift as a “build your own bottle scorer kit” with all 85 pieces disassembled. To go with the pieces, I generated this IKEA inspired instruction booklet by making exploded views for each assembly step.
