Rescue jobs

Broken mini lampshades

Broken Shades

Occasionally, we get unusual requests from customers at work about cutting or salvaging glass items from their homes and vehicles. One such request lately was for a customer who had borrowed a lamp from somebody, but had managed to break the cylindrical glass lampshades that slotted onto the lamp. Without seeing them, I told him to bring them in and at least I could take a look.

When they arrived, they were actually really small in size, approximately 30mm in diameter, and a heat formed glass cylinder with a moulded inner base tube that slotted onto a mount. This one was going to be tricky. It was certainly going to be too small for all but one of the bottle cutters I have, but I decided to give it a go with the G2 bottle cutter.


Fixed Shades

The G2 cutter is the most flexible cutter I have in terms of the sheer range of size it can cope with. I set it up, and felt confident it would rotate and give a clean, even cut on the shades. It did work in terms of size, but I could tell the score wasn’t too successful just by the feel of it. This is most likely for a combinations of two things. Firstly, the outer surface of the glass shades were sandblasted, which makes it a textured surface. Usually this needs a deeper and harder cut. Secondly, as the glass is a single formed piece with an internal cylinder, I’m guessing that the shades become slightly heat strengthened by the forming process, making it a tougher glass to cut, though not unbreakable clearly. The usual hot and cold method didn’t achieve anything at all in terms of getting the score to run. Time for plan B.

There was no other alternative to tap, run of snap it, so I tried an electric water-cooled tile cutter. As the glass was quite thin (<3mm), the tile cuter was way too brutal to cut these shades. All it achieved was giving me a good soaking. Time for Plan C.

The last remaining chance was to turn to my glass grinder that I use for stained glass making. This would be tricky and time consuming to get the very jagged edges down to being as close to a flat cylinder edge as original, but I gave it a go.

The Lamp

The Lamp

The glass ground well, and using the grid lines on the grinder top, I got the three cylinders down to as flat an edge as I visibly could, which is not easy when you consider it’s a cylinder and you are using a round rotating grinder head. They were so erratically broken, I cut them to just below their lowest breaks, leaving three distinctly different height cylinders. This was as good as I could do, without spending all night grinding. I figured it would look good as the lamp stalks were three different heights anyway, and I could place them to suit the best look. I finished the tops of with the hand diamond pads, to give them as good an flat and arrissed edge as I possible could. The internal edges were too small to do anything with, but I was satisfied they were as safe as I could get them with the grinder.

End result

End result

All in all, I’m quite satisfied in how it went, as the job was really just a ‘make best or bin’ gamble with what had become a damaged and unsafe lamp. It looks pretty good in the end, and was a fun little challenge to do. I don’t mind tackling something like this, as you’ve nothing to loose, and it’s good experience with bottle cutting skills on objects other than bottles. A worthwhile and interesting task.


Backless Bottom Centres

Right from the start of mixing bottle bottoms with copper-foil designs, I’ve used a 3mm UV-bonded clear circle blank as a backing piece for the bottle ends, as I’ve always felt it adds strength though a fully soldered joint and overall appearance improvement. Occasionally though, despite very careful bonding, and neat soldering, a few drops of water have sneaked through into the enclosed bottle bottom cavity when washing away the patina. I’ve managed to dry them out using natural sunlight, open fires and even industrial desiccant, but it’s not without some water streaks left inside to drive me mad! No-one notices them, but I do. I still think it’s by far the best way to make them though, but out of curiosity for the alternative, I thought I would try one without backing as an experiment.rearsoldering

I begun by foiling the cut edge of the bottle bottom, which , with care, wasn’t as untidy as I thought it could be. I lifted the bottle end up towards the front surface using some 3mm glass, ensuring the front solder was as substantial and visually neat as the backed centres method. This ensures a good looking front face, which is the most important thing in a window hung design. This leaves a step between the two rear foiled surfaces, for solder to form a sloped join.backlessamber The result is ok, but does need the sort of working that puts a lot of heat in during smoothing. It’s pretty strong, but what I don’t like about this method is that it leaves a tinned edge on the upper edge of the round, which is a little bit vulnerable to careless cleaning. From the front, you wouldn’t really tell the difference between the two methods, and it looks good hanging on a window surface. I guess time wise, it probably saves a good half-hour or so from by cutting out the  need for a 3mm circle and the UV bonding, but I still prefer the end results from the backed method I’ve been developing over the last year or two. It’s been useful to try it out, and I would use this method again on a design that is very one-sided in viewing orientation.

Better finishing

With a real turnaround in the weather after what has seemed like months of rain, I’ve been busy collecting more bottles from the streets , and trying to plough through quite a big backlog of bottles building up in the yard. I’ve recently passed the 100 bottles mark of bottles I’ve picked up off the streets in the ten minute walk home to and from work. Many have been reused, with surprisingly few being too badly scratched to attempt, which get recycled.

I’ve been trying to improve techniques, and really have the cutting and breaking down to a good standard now, leaving as little finishing as possible, but it still takes some time to get to a good standard that I feel happy with. I’m still astounded at how some cut bottles are presented as finished in books and on the Internet, when they are very poor and uneven. A quick rub round with sandpaper really doesn’t cut it.  I want it totally smooth, as uniform as possible and as safe as possible for an edge that is manually finished. Getting small shells on the inner surface has always proven to be the biggest problem when flatting off the cut face. It’s harder to finish the inner edges without catching a surface and leaving scratches, so these shells can leave the edge too difficult to finish to the standard that I want to achieve. I’ve been varying the method order, and started to gently edge the inside edge first, on a shallow angle at first, holding the bottle firmly on it’s side on a wooden surface to avoid movement. When I get the inside edge to a good enough standard, I move onto the outer edge, repeating the holding down technique to minimise movement. Once both edges are complete, only then do I begin to use the flat of the diamond pad to level off the width of the cut surface to remove all crater signs and level it off, creating a nicely clean , “flat and arris” style edge. This was the process that added a few edge shells to the thinner bottles, so leaving it unitl the edges are done reduces the risk dramatically. I should have worked out this sooner, but now I have, it’s producing massively better and more reliable results,  and actually reduces the time taken by around a half – a real bonus, when the finishing process is the major time consuming one compared to the cutting itself.

So there you have my process recommendation:-   inside edge, outside edge , flatting

Water breaking

After a good deal of experimenting, and observing other people’s methods on the Internet, I’ve settled into a routine method for cutting and breaking glass bottles that really works well for me. I guess it’s about finding your own preferred method, but some of the well publicised ones , to me at least, leave a lot to be desired, and the results demonstrated speak for themselves. In this post, I hope to break down the steps I take to demonstrate my best method of cutting bottles, which is one I regularly get around 80%+ success rate with. Though not as demonstrative as a video, the photos and blog post should hopefully still  be useful to follow my own chosen technique, which has worked very consistently over several hundred of cut bottles so far.

The first step to cutting a bottle successfully is the most obvious, but often the most overlooked in terms of a prime reason why the bottle cutting fails. There are some methods of breaking a glass bottle using heat from an acetone-soaked string line, or an electric current, or even hot oil inside the bottle, but most demonstrated results are often quite poor. I only use, and recommend, the traditional glass scoring technique, using a glass or dedicated bottle cutter.clean scoreline This helps to create a consistent and clean score line which should run well if performed correctly. This is the key stage to a successful cut in my opinion. A singular, light, clean and unbroken score line is essential, and, beginners to the hobby might be tempted to have a heavy score line to feel they are breaking into the glass. Heavy scorelines, that leave lots of flakes are the most likely to crack and run off when breaking commences. A consistent, gentle pressure with the two ends meeting is what you need. Ensure your wheel is lightly oiled, and don’t go over the same scoreline twice. You want a nice, clean scoreline as the photo right. Without this clean start, the odds of a poor break are magnified.

hot water pourWhen it comes to the breaking, I’ve settled on the hot and cold water method observed on YouTube, with reliable and good results right from day one. The Ephrem’s cutter comes with a candle to use in conjunction with a block of ice, but I found that technique very unsatisfactory. It was messy, slow and gave poor results. I much prefer to use a pouring kettle, and a cold running tap. Depending on the thickness of the glass (thinner glass go slightly cooler), I use the kettle just “off the boil” (around the 70-80 degrees Celsius mark, though I don’t use a thermometer). Using a kettle means you can pour a neat line of water just over the score area, without letting it spread too widely across the body of the bottle, which I find helps a great deal. My preferred method is to use a sink bowl for balancing the bottle, and rotate the bottle around a few revolutions, pouring the hot water over the score as i rotate slowly.  fracture lineI used to try creeping the cut by flashing a section with hot water and immediately quenching it under the cold, but this isn’t as consistent as a full score heating by several turns. When I gauge the bottle to be hot enough after three or four turns, I then rotate the score under a slowly running cold tap, turning it fully to quench it as quickly and uniformly as possible. This should give you a clearly visible fracture line all the way around the bottle, as photographed to the right. When you have this look all the way around, without any runs, you know you’ve got it sussed.

clean breaks

A second, gentle pour with some hot water is usually enough to separate it fully at this stage, and the two parts completely separate without any human touch required, leaving clean edges ready for smoothing. No bottle will be completely flat when separated, but this technique gives you consistently very straight edges as the photo to the left shows, which are straight-forward to finish (see my preferred method in the post edge finishing) . I’ve used it on thin beer bottles, small condiment bottles, wine bottles and very thick whisky bottles all to a good standard. It’s by far the best way I’ve come across so far, regardless of which bottle cutter you initially use.