The Best Way to Cut Glass Bottles

Cut the top off of a bottle for a nice, usable container

Old glass bottles may be turned into very useful and solid containers used for toothbrush holders, plant starter pots, parts holders for screws and nails, and a host of other applications in which a small container is needed. Since most bottles taper at the tops to form a drinking or pouring spout with cap on top, most bottles must have the tapering tops cut off for them to serve any useful purpose other than to hold liquid for pouring. An inexpensive way exists which exploits the physics of the glass.

Things You'll Need

• Sink filled with cold water
• Thick kite string long enough to go around the wide portion of the bottle
• Nail polish remover
• Dry piece of cloth
• Pair of leather gloves
• Eye protection goggles
• Wooden match or cigarette lighter
• Metal file

Instructions

1. Fill a sink about half full of cold water. Allow the water to run for about 30 seconds to one full minute to ensure it's temperature is as cold as possible, and then set the drain plug and allow the sink to fill.

2. Wrap a piece of kite string around the portion of the bottle where you would like it to snap apart, pull as tight as possible and then tie the ends to keep the string's form. Remove the tied string ring from the bottle by sliding it over the top.

3. Dip the entire circular-shaped piece of kite string into the nail polish remover until it is completely saturated, then remove and allow excess to drain.

4. Place the string back over the glass bottle, sliding it down over the top and lowering it into the desired location once more. Use a dry piece of cloth to wipe away any nail polish remover which may have smeared on the glass so that the only area with the polish remover is on the string itself.

5. Put on a pair of leather gloves to protect your hands from any glass or flames from injuring your hands. Put on eye protection goggles just in case any small pieces of glass fly outward from the snapping glass circle. These goggles would be necessary if using a high-speed diamond wet saw also, so be sure to use them regardless of the method.

6. Hold the bottle over the sink of cold water and light the string on fire with a match or a cigarette lighter. Once the flame ignites, rotate the bottle around slowly and evenly so the string heats up the glass under it evenly. Rotate the bottle for about fifteen to twenty seconds.

7. Plunge the entire bottle into the cold water and use your hands to apply a snapping, bending movement as the bottle submerges under the water. The rapid "hot-to-cold" contraction of the glass will cause the two halves of the bottle to snap apart relatively cleanly. Use a regular file to dull the sharp edges to prevent cuts when using your new glass container.

Tips & Warnings

• Do NOT just simply heat the bottle with a flame, as this will heat a larger surface area of the bottle causing it to shatter when hitting the cold water rather than snapping apart. Shattering such as this may cause flying glass and cuts. The purpose of the string is to concentrate the heat into a very narrow line, which is where the "cutting" action comes from. Don't omit the step using the kite string.

References

• Internet SIAO