Archive for the Bottle Cutting Category
There are two significant changes from version 1:
1. Width adjustable to accomodate wine bottles of various diameter.
2. Rubber bands on wheels for gripping bottles to prevent slipping.
One of the most hexing things about using this device, especially for bottles of larger diameters, is ensuring that everything is aligned and calibrated properly so that the start of the score line meets the end. If there is an offset, it will have a negative impact on the cutting. This device needs a few more modifications before it can be considered production worthy.
Bottles, bottles everywhere…but not a drop to drink.
I work in DUMBO. Next to my building there is a swanky new condo apartment building. Every Friday, maintenance puts out blue recycle bags filled with such bottles. I go through them and pick out the ones that I like.
I could have salvaged a few more but I didn’t want to seem greedy or anything.
Bottle cutter version 1.0 is described here.
This bottle cutter has been specifically designed and calibrated to handle 12 fluid ounce beer bottles. Unfortunately, it is not big enough to handle the girth of larger wine bottles. At the time, I didn’t know whether my device would be able to fulfill what I had intended it to do. I was more concerned about “proof of concept” than anything else.
Last week, I drew up some diagrams for a new and improved version. The key new feature of this second generation device is that it would be width-adjustable.
click to view pdf
I had described, in a previous post, a method of splitting glass bottles that involves the use of a propane torch. This method is problematic. The glass is very sensitive to the extreme heat of the torch flame. If there are any structural irregularities in the glass, exposure to the torch flame heat will result in unpredictable crack lines, instead of a nice, clean, straight cut that follows the score line. Out of five attempts, only two resulted in an acceptable cut and even with these there were some unevenness that had to be rectified with a grinder. A 40% success rate is terribly inefficient. It results in a lot of wasted bottles.
Currently, I use a different method which was developed by a physicist who does this to make vacuum chambers. Such an application would require rather precise cutting. It’s pretty simple. After etching the score line, you pour boiling hot water over the line while turning the bottle slowly. Then you pour cold water over the line in the same manner. You repeat this process until the bottle splits. It takes about four or five passes before it splits.
I call this the Chinese Water Torture method. I heat the water using my Krupps coffee machine. It’s faster than boiling a kettle of water on the stove. I also like the fact that it eliminates the cost of having to get a propane torch.
Until now, Heineken was my favorite bottle of choice when it comes to bottle cutting. Tonight I experimented with a Jinro Chamilsul soju bottle. The results can be seen above.
The most obviously noticeable thing is that the soju bottle is almost twice as thick as the Heineken. The other thing I noticed is that the soju bottle also splits in much more cleaner manner.
The soju bottle is on the left and the Heineken is on the right. Compared to the Heineken, there are less chip marks on the cut edge. In fact, the soju bottle split so well that I don’t think it is necessary to grind the edge like I have to with the Heineken. I’m still not sure, though, whether this is due to the fact that the soju bottle is made of better glass or if it’s because my bottle cutting skill has improved. For the Heinekens, I am currently finishing the post-grind edge with a rub of petroleum jelly and a coating of nail polish hardener.
I need to get a decent macro lens to take better close-up photos.
I resumed my nocturnal bottle cutting activities recently. Bottle cutting is an obscure art. Not many people do it and there is not a lot of literature on how to do it.
Glass is a difficult material to cut properly. If the molecular structure of glass were crystalline, like metal, this would all be so much easier. But unfortunately, glass is an amorphous fluid. That means any attempt to cut glass may produce unpredictable results. The cutting of glass itself may be best described as “controlled shattering”. Ideally, we want it to shatter in a straight line.
In order to cut glass, you must first etch a line with a glass etching hand-tool. Etching a line on a flat piece of glass with a straight-edge is easy enough but etching a straight, even line around the curved surface of a bottle is a totally different matter. That is why I built this custom-made device. There is no other device like it in the world!
This is how the bottle goes onto the device. Everything has to be measured and calibrated precisely, which is why you see an architect ruler in the photo. The bottle is slowly rotated with manual pressure applied. A cutting bit underneath etches a straight circle around the bottle. BTW, that happens to be a Heineken beer bottle.
The etched line must be heated with an open flame. I use a propane gas torch, which can be bought at Home Depot. Some people suggest using a candle flame but based on my own experience, I do not recommend it. A candle flame will leave a dark ash residue around your bottle. On the other hand, the propane flame burns cleanly so it won’t leave a residue. However, it’s much hotter than a candle flame so you have to be much more careful when heating the bottle. Apply too much heat and it can crack the bottle rather unceremoniously.
After the bottle is heated, you dunk it in a large container filled with cold water. When a material is heated, it expands. When it is cooled, it contracts. The idea is to use this expansion-contraction to apply shearing stress along the etched line around the bottle, thus leading to a controlled shattering.
So here are some sample of bottle that I have cut in the past. The cut edges are very sharp and jagged. It needs to be grounded down with an angle-grinder power tool.
Why cut bottles? I really don’t know how to describe it. As I mentioned before, it’s not easy. It takes skill, discipline, and lots of patience. But it is a very satisfying feeling to be able to perform a difficult task and do it well. On a practical note, I plan on using these cut bottles as containers for my impending project, which is making soy wax candles.