This instructable is about a rather old project of mine. But as it seems, it didn't get too popular since then. I hope it changes after the submission of this instructable.
So what is it about?
The main idea describes how to clearly cut off the bottom from any glass bottles and then reuse it for something beautiful like a lantern, a flower pot, a vase or something totally different.
So for the first part you need:
a big bowl with cold water (may add ice, but without it works too)
40cm of a woolen thread for each bottle (any color, cotton works too, but no synthetics!)
a few empty clean and dry glass bottles (I prefer 0.7l wine bottles)
a few drops of petrol (the one that comes for your lighter works great)
a lighter or some matches
a glass cutter
Step 1: Carve the Bottle
Take the glass cutter and one of the bottles.
Well glass cutter is a bit of a strong word for this device, as it only carves in a small notch. With flat glass this is enough to perfom a smooth break along this notch, when the glass is bent. Unfortunately not so with round bottles, but one step after the other. First we need to carve the notch at the same height all around the bottle some few centimeters from the bottom of the bottle.
Go and find some timber or a book to adjust the height of the cutting edge roundabout 3cm above the table. Hold the glass cutter straight down and move the bottle on the table to get ONE clear notch. Don't try to go over and over again, this will only worsen the problem. First try with a few spare bottles before you take your best one. You need quite a bit of a strength to get this notch straight.
You could also clamp the cutter to some timber or build a v-shaped device to cut it.
Step 2: Tie the Woolen Thread Around
Now you should have a glass-bottle with a small notch all around the bottle.
So then take the woolen thread and fix it on the notch. Try not to make a big knot, it doesn't have to hold much. After that trim the ends.
Step 3: FIRE!
This step should be done outside in some fireproof area! Please be careful! Before you start set up a spare bucket of water and an fire extinguisher.
Minors should consult their parents for help with this step. Handling with fuel and glass can be very dangerous!
O.k., but now on with the show: Get the bowl and fill it with cold water, if you have you can put some ice inside, but keep it liquide! ;-)
Then take the lighter fluid and carefully soak the woolen thread with petrol. Normally a few drops around the bottle are sufficient. We don't want to burn down the house!!
If you spill too much, let it evaporate outside and start new. Adding to much petrol will surely burn your hand and destroy the bottle.
If everything looks good, hold the bottle at the neck with the bottom up and light the soaked thread. It should then burn about 20s maximum before you quickly immerse it into the cold water. This also extinguishes the last flames.
If it worked you have heard a small crack. Maybe you still have to carefully knock the bottom of the bottle, but that should go very easy.
Step 4: Smooth the Edges
Now you should have a bottle without a bottom, but with a straight and sharp edge. So go and use some sandpaper or your special tool and smooth the edges.
I used sandpaper by hand, but this tool does the same job much faster: Craftsman cordless rotary tool.
If you didn't do a great job and the rim is broken and unstraight, try to cover it with some special tape. There are self adhesive aluminium-tapes and I think even copper tapes available. Give them a try and cover up the bad rim.
Step 5: Use the Bottle Without Bottom
This is the most creative part of the instructable, because now you can do whatever you want with this bottomless bottle.
The next steps will present some ideas: A flower pot, a lantern (wall mounted and free hanging), a scent lamp for ethereal oils.
Step 6: A Flower Pot
To use it as a flower pot indoors you plug in an old cork to seal the neck of the bottle and fill the bottle up with earth and plant something in it.
Try to screw the cork to a wooden basement plate, this way you're free to set up the bottle wherever you like.
Sorry there are no pictures of this usage so far...
Step 7: A Lantern Wall Mounted
To use it as a lantern you need some kind of mounting and a plunger for the candle.
The plunger is made very easy from a piece of wood that fits inside the bottle and a metal pole in the length of the bottle. I used a half cork to fix them together, just look at the pictures.
Try not to make the wooden part perfectly round as this would seal up the bottle causing the candle to flicker and burn down unevenly.
To make the wall mount, I used two shelfs with a suitable hole in one of them for the bottle. Additionally I added a corner beneath the horizontal shelf. You have to figure out the sizes by yourself, because I believe none two bottles are the same.
Step 8: A Lantern Free Hanging
For the free hanging lantern you only need two meters of a metal chain. Open the chain links with pliers and create a cage for the bottle. Just look at the pictures to get the idea.
Step 9: A Scent Lamp for Essential Oil
Some years ago these scent lamps were really famous but in the meantime they have nearly disappeared. I still like them and this is a variation of the wall mounted lantern.
You only need a small metal bowl or something looking like a watch glass but made out of metal. This is put on top of the bottle that is now wall mounted. Then you only have to fill in some water and a few drops of essential oil and if you light up the candle the whole room will be filled with a decent scent.