Adventures in Bottle Cutting

**This post involves a method for breaking glass.  Please take any and all precautions as indicated by the packaging of the tools used to ensure your safety.  Safety goggles and gloves are your friend!  Broken and cracked glass WILL have sharp edges so be careful that you don't cut yourself.**

I'm learning a new skill!!  I had thought about bottle cutting a while back and just kinda dismissed the idea, not really sure why.  Then I got to thinking.  If I cut up some bottles, and smoothed the edges down, I could use those for beakers instead of shelling out money for real labware.  Labware has a tendency to be very pricy.  Anything that has measurements on it has to be reasonably accurate and the smaller the measurements the harder that is to do.  Consequently, the more accurate you want your stuff to be the more it costs.  Now, I don't really need anything that measures accurately...well, not for party purposes anyway...so having graduated glassware isn't really necessary (graduated in this case means "marked with measurements" because scientists can't say anything simply).  I just need stuff that looks cool.  The other nice thing is that bottles are pretty easy to come by.  I have any number of households that I can tap for wine bottles, mine included, so it's not like I would have to spend more to get bottles.  Go, recycling!  Actually, this is probably repurposing or upcycling (honestly, can you keep track of all the new terms?  I know I can't.  What happened to plain old "recycle, reduce, reuse"?) but either way it's better for the environment than just throwing the bottles out.  Repurposing is even better than recycling since the bottles won't have to be melted down (which uses fuel) or anything like that.

Having established bottle cutting as a viable craft for my purposes the only thing left to do was get a bottle cutter and start cutting...or so I thought.

A quick run out to my local craft store netted me a bottle cutter that wasn't terribly pricy.  I had a 40% off coupon too, which certainly didn't hurt.  The method it uses is "score and tap" where the idea is that you etch a line around the bottle and then tap it with the hammer (not a normal hammer, it's actually just a bit of shaped aluminum but it's called a hammer probably because of the tapping).  The score line is supposed to weaken the bottle enough that with gentle and repeated tapping the bottle with crack along the score line.  This the point where you realize that "bottle cutter" is a bit of a misnomer.  You don't actually cut the bottle, you just break it in a very controlled manner.  Unfortunately, that was where I hit my first hurdle.  The assembly of the scoring jig was a bit iffy and the layout just didn't make sense.  Still, I persisted and was able to get a score line, or rather, something that looked like it could be a score line eventually.    The problem ultimately turned out to be that there was no good support for the bottle so my score lines (I did a bunch of them for practice) weren't straight or continuous.  They sloped up and down as the pressure I applied to the bottle caused the base to slip which in turn would cause me to have to reposition the bottle and try to restart the line.  It was very frustrating.  If I didn't apply direct pressure the blade wouldn't etch at all but if I applied direct pressure the bottle moved.  The reason it matters is because the bottle will break along whatever line happens to be there, not that I ever got that far.  My several attempts at a decent score line had also started giving me something that felt like tennis elbow.  ARGH!


It was time to consult the interwebs.  That in itself was a terrifying experience.  The most prevalent DIY method for bottle cutting seems to be "flaming string" which is enough to give you nightmares if you actually think about what it involves.  For flaming string you soak a bit of string or yarn (hopefully of the natural fiber variety, I can't imagine using a synthetic would be anything like a good idea) in alcohol or acetone, wrap it around the bottle where you want it to break and light it on fire.  Once you've evenly heated the bottle around the burning string line, you dunk it in cold water and the bottle cracks off at the string line.  Now, admittedly it sounds really fun (and you get to play with fire and everything!) but that's exactly the reason why I know this can't be a good idea.  Nothing that sounds that fun is EVER a good idea.  For starters, burning acetone makes some really funky fumes (yeah I've set acetone on fire before. In case you're wondering, I really don't recommend it.  Learn from my mistakes, people!) which you won't be able to avoid breathing; you have to hold and rotate the bottle so you can't get away from the flame.  Using alcohol is a little better fume wise but then you run into the issue that both the alcohol and acetone have.  They burn, and burn, and burn plus their fumes are flammable.  That means if you leave drip lines anywhere or there's too much liquid on the string and it drips off the fire is going to follow it.  You may think you're being careful but I'll tell you right now it isn't worth the risk.  I taught a fundamentals lab for microbiology where students were taught how to sterilize glass tools by dunking them in alcohol and then lighting the alcohol with a Bunsen burner flame.  This was a controlled environment with someone (me, in my classes) supervising who had used the technique countless times.   Still, at least once a semester we would have a student really light things up.  Once we had a student light the entire bench on fire.  You would not believe the number of times we had fires even after everyone got the process figured out.  Happily, they were usually tiny fires.  Usually a flaming drop would fall and hit a vapor trail or something and before you know it, the jar is burning like a campfire and so is any alcohol that hit the bench.  Your choices then are to let it burn out on its own or suffocate it, nothing else works.  Sill, setting a lab bench on fire is surprisingly OK because they are built to handle that kind of abuse; your kitchen counters and craft tables probably aren't.  None of that even goes into the quality of the glass or the evenness of the heat stress line.  Having problems in that area can do things like make the bottle explode.  Needless to say I most emphatically do NOT recommend using the burning string method.  I'm rather attached to my skin and lungs and so try to avoid things that have a good chance of damaging them.  I'm also quite fond of my kitchen, it is where the food comes from after all, and prefer it to stay functional.

There was a light at the end of the tunnel, however.  My mom found the website of a guy named Ephrem and it looked amazing.  We watched his video and were amazed how simple his system is.  You score the bottle and heat the score line over a candle.  Then, when the bottle is hot enough, you run an ice cube over the score line.  The hot-cold contrast stresses the glass the same way the flaming string method does but this one is much more well controlled and considerably less dangerous.  You're also only dealing with a candle which burns at a lower temperature than alcohol and the slow separation has to cut down on the number of oops explosions and other problems.  In the video it took him a few applications of hot and cold to get the bottle to break but once it did break the edge was enviable.  The break line was nice, even at the edges, and apparently only took a small amount of polishing to dull it enough to be safe.  I conceded the loss with the other cutter (which also happens to be impossible to disassemble and therefore impossible to return. Are we surprised?  Not really.) and ordered Ephrem's deluxe bottle cutter (it has an adapter that will allow cutting on the curved edges of bottles).

Ephrem's bottle cutter with adapter.  I had turned the back stop around by this point.

I was a little nervous about the cutter because I had seen some really negative reviews of it.  But then, with most of the cutters available people either seem to love them or hate them.  There isn't a middle ground.  You'll see one and five star reviews almost exclusively.  The most negative reviews for Ephrem's bottle cutter said that the glass won't break cleanly and that you'll be left with a sooty, jagged mess.  The most common complaint was that the adapter didn't always come with the set when it was supposed to.  This apparently was due to resalers not knowing what the difference was between the standard and the deluxe model.  The most positive said that it works exactly as advertised and is really easy to use with great results.  So, like most things, I figured it had about a 50/50 chance of working out.  I would just have to wait and see.

The extremely prompt response I received gave me hope; I heard from Ephrem a few hours after I placed my order, and on a Sunday no less. You don't always get that kind of service with random website Paypal purchases.  While waiting for my bottle cutter to arrive, I cleaned up a few bottles that I had about the house.  Nothing fancy there, just a long soak in warm water to loosen the label followed by some paper peeling and a quick scrub with one of my scrubbies to get the adhesive off.  Plus I still had the practice bottle for my first tries at a score line.  I kept it around because, with the number of attempted scores it has, it won't be useful for anything besides preventing me from wasting bottles.

See all my pretty (and not so pretty) score lines?  This is my practice bottle.  Just a quick note, if you use a practice bottle like this you have to make sure that none of your lines overlap bc it can damage the cutting blade.

My bottle cutter arrived on Wednesday, which pleased me greatly.  Three day turnaround is not something I expect out of anyone but Amazon.   Excited about my new toy, I promptly grabbed my practice bottle and had a go with it.  The difference between Ephrem's bottle cutter and the plastic one I got at Michael's was astonishing.  It worked so easily!  My score lines stayed nice and straight and the whole setup worked exactly as advertised.  I did have to tinker with the jig a bit; it didn't have the range that I wanted.  It was set to something like juice glass length and I had wanted to try my first cut higher up the bottle than that.  The solution was quite simple, I just took the back stop off and turned it around.  Much better range, and I really like how adjustable the setup is.  I did notice  that the adapter that lets you cut on curves is a little loose.  I think I'll have to tighten the nut securing it considerably before using it otherwise the piece moves and the score line will move with it.  I haven't tried that yet, but I'll let you know how it works out when I do.  With more use I may make a few more alterations.  For instance, I've heard that bolting it to a cutting board can be really helpful.


Having assured myself on the practice bottle that I could get something like a good score line I picked up a fresh bottle and tried it for real.  The score line went marvelously and with no hand or arm cramps which meant it was time for the moment of truth; it was time to heat shock the score and cut the bottle.

Sorry for the lack of pictures here, but I only have two hands.  I couldn't manage to rotate the bottle over my candle and shoot what I was doing at the same time.  For the heat shocking you heat the score line over a candle and then touch it with ice.  Oddly enough, this is the bit that I think is going to take the most practice.  I saw some negative reviews about how this method with leave a sooty mess on your bottle.  It is true that if you put the bottle in the candle flame it will soot the bottle.  That's why you hold the bottle a bit above the flame.  It just takes some practice.  I did get a couple of smudge marks on the glass, but that was because I was trying to figure out the best way to hold the bottle and how to rotate it smoothly.  The other bit that takes some patience is getting the bottle hot enough to crack on the score line.  It took me three tries to get it to break, but again that would be inexperience talking.  Finally I heard the little popping noised that indicated the score was cracking.  It didn't break all the way off so I did another pass with the candle and POP!  there it went!  One nicely cut bottle!  I dried it off and took a look at the edge and saw immediately that all the negative reviews I had seen were very, very wrong.  The edges were sharp which was to be expected, it is technically broken glass, but the edge itself was as close to perfectly even as it's possible to get.  

Unpolished cut edge.  It is sharp, but the variations around the edge are too subtle for my camera to pick up.

The edge was so nice, that I could actually put the bottle back together!  According to another guy's website, he cuts bottles with a score line and hot and cold water, it should be possible to have the bottle hold water at this point as long as there is pressure holding the bottle together. 

I waited a few days until I could cut a few more bottles, and get some parts, before I sat down to polish the edges.  In his videos, Ephrem uses a piece of glass as a base for the polishing process. I thought about that for a while and did a bit of research.  Glass on glass polishing is actually one of the best methods so I figured it was time to get some plate glass.  I started with my local hardware stores and was very disappointed to find out that neither of them sell piece of plate glass or Krylon Looking Glass spray paint.  I'll tell you more about that second bit in a later post.  I was then hit with a stroke of brilliance and decided to go to Ross in search of a small glass cutting board.  This seemed like a superior solution to just a piece of glass because the cutting board has nice smooth edges and little gripper feet so not only can you not cut yourself on it, it also won't walk away while it's in use.  The cutting board has the additional advantage of being a good size to store.  I returned home with my prize and cut my remaining bottles so that I could do a round of polishing and call it good.

I'm glad I did a few more bottles, too.  I learned some very useful things that I can now share with you.  All three of the bottles I had were clear glass and two of them were from the same winery.  The loner bottle cut like a dream but the sibling bottles did not.  I think this is one of the points where people get frustrated.  The matching bottles scored well enough, I had to redo one of them because the line I got was mostly oil and not score mark and you aren't really supposed to re-score the bottles, but when it came to separating the pieces things went wonky.

This was the first of the matched pair that I separated.  I'm not sure which of the two had the repeat on the score line, I think it was this one.  On this particular bottle the crack you see in the picture happened when I was icing the score line.  It came apart really easily so I didn't have to decide if it was a good idea, or not, to put it back in the candle flame.  I had heated the glass a little longer than I had intended, something like 3 minutes, and the glass turned out to be thinner that I had thought so it is entirely possible that the crack was do to either excessive heat or a flaw in the glass itself.  I don't know enough about glass to be able to say for sure but I suspect it was a combination of the two.  I have been to the Corning Museum of Glass (we went in 2011.  It's really awesome, you should check it out if you're ever around Corning, NY) and what I remember of their various exhibits and demonstrations does fit the flawed glass hypothesis really well.

This was the second of the twin bottles.  I heated it for a lot less time than I did the first bottle.  This one only got heated for maybe a minute before applying the ice.  As you can see, the break was not a clean one. The break line deviated from the score line in a number of places, the most obvious of which is shown.  Since I had problems with both bottles that very likely came from the same lot of bottles (the wine was purchased on an actual visit to the winery where it was made and I believe both bottles held the same thing, which means they were probably bottled in the same batch and therefore came from the same lot of bottles) I figured that the problem was likely the quality of the glass used.  I became convinced of this when I compared one of these bottles to one that didn't have problems.

The bottle on the left is one of my problem bottles, the one on the right is the first one I cut.  What I want you to look at here is the thickness of each bottle.  I don't have calipers, not sure why, so I can't tell you what the actual thicknesses are in meaningful numbers but I think it's pretty obvious that the bottle on the right is at least twice as thick as the bottle on the left.  I've read that the thickness issue is part of why beer bottles can be a challenge to cut nicely. When the glass is thin any of the flaws it might have will make a bigger impact.  I'm going to have to learn to judge bottle thickness so I can cut down on this sort of problem.

With my cut bottles ready to go I broke out the new cutting board and the carbide powder that came with my bottle cutting kit.  What you do is put a bit of the carbide down, add a little water, and then rub the cut edge around in the resulting mess.  It is as easy as it sounds, but there is one thing you really ought to know about.  Polishing the cut edge makes an ungodly amount of noise.  The hollow space inside the bottle and under my cutting board make echos like you would not believe.  My cats were severely displeased and I can't honestly say I blame them.  It was loud and it was annoying.  More so if the cut part wasn't reasonably even but I'll get to that in a bit.

This is what the polishing setup looked like.  All I had to do was rub the bottle around in circles on the wet carbide and the abrasiveness of the carbide would even out any rough spots.  I was surprised at how well it worked, I just didn't enjoy the noise it made.  The edges felt smooth to the touch after a very short time, maybe a minute or two.  It was nice that it didn't take very long.

This is the base of my first bottle after I had given it a once over on the carbide.  When I was working it I would periodically, and very carefully, run a finger over the broken part to see if it was still pointy or sharp. I stopped when the edge felt smooth to the touch which only took a minute or two.  What I want you to look at here is the edge of the bottle, I've made it large to make it easier to see.  Around the edge you will see sections that look matte and are almost grey in color as well as sections that look so dark as to be almost black.  The dark sections are actually shiny but my camera wouldn't pick that up.  The matte section are where the carbide did it's work and the shiny parts are areas that didn't get polished because of very subtle differences in depth.  I wasn't able to see this difference until I got the carbide cleaned off.  If what you're making isn't going to touch skin, like if it's the bottom edge of something that touches the ground, the level of polish probably won't matter so long as the edge sits flat and isn't sharp.  For something that was to be a drinking glass, for instance, I would take it back to the board and polish until the entire cut edge has the matte look.  The last thing you want is something that could accidentally injure a family member or guest.

Another thing you're going to want to be aware of is that carbide is really abrasive.  I have a ceramic sink which scratches easily enough with regular dishes, so when the time came to wash the carbide off the bottles I used an old kitty litter tub as a wash basin and a paper towel as a wash cloth.  When I was done I poured the used water into the section of my garden where I empty craft buckets.  Even if you don't have a ceramic sink you may want to take that precaution, unless you've got a utility tub or something.  Carbide probably isn't the friend of your garbage disposal either so I would recommend against washing carbide off in your kitchen sink just to be safe.

I don't know about you, but I was wondering how well the carbide method worked on the really uneven pieces.  I grabbed the fail bottle with the uneven edge and gave it a try.  I discovered very quickly that the noise on uneven edges is far worse than the more even edges.  Another point of interest is the shape that it created in the carbide.

You'll notice that there are a lot of gouged looking swirly areas in the carbide.  That's what happens when the edge isn't even.  If you're working on an even piece the carbide makes an even layer with very regular swirls.  I think that will make a handy trick for knowing when you're close  being done with polishing.

Working the uneven edge makes it very obvious which spots are being worked on.  I tried to balance the bottle so that I wouldn't wear down the other side of the bottle while working on the wavy edge.  I learned that the bottle will try to skip about every time the pressure changes on the uneven bits and every time it skips it makes a noise rather like fingernails on a chalkboard.  ::Cringe::

I had a hard time getting the camera to focus on the bits that I was trying to wear down.  I don't think it liked the carbide "fuzziness." I took that picture after about 10 minutes of polishing.  The edge still isn't even but it is a vast improvement.  The only unfortunate bit is how long it takes; swirling the bottle about for that long gets rather boring.  The important part is that it can be done with a bit of patience.  The alternative is to slice of a bit more of the bottle which I shall try on another occasion.  I'm just pleased to have more than one option when it comes to bottles that try to oops.


Review of Ephrem's Bottle Cutter
I've decided to start reviewing new things that I come across.  A bunch of reviews are from websites like Amazon which are usually pretty good, but you can't always tell which posts are plants by the vendor.  Sometimes the reviews are just ranting by an extremely frustrated person, but even then you have no way of knowing how they actually used whatever it was.  To that end, I hope to be as informative as possible by giving you a crafter's perspective.  Please keep in mind that I am a complete novice when it comes to anything glass crafting.  Until I got this cutter I had exactly zero experience with bottle cutting.

Pros:  I have to say that I was very impressed with the bottle cutter.  It works exactly as advertised.  As with any new craft, it does take a bit of practice to familiarize yourself with the process but once you get it down it is really, really easy.  I had absolutely no problems with the cutter itself.  Any issues with uneven breaks seem to have been the bottle having a problem rather than the process being faulty.  The process worked just fine.  I had little to no issue with sooty bottles once I got steadier holding the bottle.  I washed the bottles at the start and the end of the entire process only, so all the pics that you see of the break lines are how they looked with no touching up.  Polishing the bottles takes time, but I don't feel like it takes an unreasonable amount of time.

Cons: If I could change one thing about the cutter it would be to make it a little bit more adjustable so that it could work more easily with smaller bottles, but I'm not certain how that could be accomplished.  I think the reason you can only move the rollers lengthwise is that it would be really unstable if you could also move them widthwise, though roller adapters, like the curve adapter, might work.  Hard to say though, too many moving parts usually spells disaster for simple tools like this.  Another potential con is the noise that the polishing makes.  It's loud!  I probably should have expected that, it makes sense that it would make a fair bit of noise.  Still, I'm considering getting ear plugs because I'm not going to stop smoothing edges.

Notes:  Be patient and be prepared to do a lot of practice scoring.  You might get it figured out in a try or two, but then again, you might not.  I found having a practice bottle to use just for scoring to be helpful.  Don't rush the heat shock portion, it will ultimately make the process take longer.  If you're like me and want things done now! you might want to use a timer for the heating part.  I found it took between one and two minutes to heat the glass completely and evenly enough for it to break.  That will change with the thickness of the bottle, so you will have to experiment to see what works best  for you.  An absorbent cloth under the bottle to catch the melting ice drips is also handy to have around, unless you like puddles on your work surface.

Love It or Leave It:  Love it!  I would absolutely recommend this to anyone who wanted to cut bottles for general crafting purposes.