I, being that im a glassblower, have tried this type of recycling arrangement with my bottles and plants... I found that it is much better (safer) to drill holes in the bottle (rather than melt or blow through). The drill bit to be used is a diamond impregnated core drill (pricey) this can be purchased from a stained glass supplier. The most important points of drilling bottles is that;Originally Posted by OrchidTraci
1. you must keep the glass wet while drilling.
2. you must not get your drill wet.
3. keep the whole arrangement absolutely still while cutting.
To remove the top from the bottle you can use an ordinary glass cutter (2-4$)
I pinch mine in a vise grip and then just spin the bottle freely to mark the circumfrence. The one problem I have there is that you end up with an unattractively sharp edge (which can cut an arial root or two). This can be filed or melted, although it is difficult to do both. I use copper tape intended for stained glass work, I center it on the edge and fold it over on both sides, burnish it down and voila! With time the copper wil patina nicely.