**UPDATE August 4, 2015**I'm changing my rating from 2 stars to 5 because this bottle cutter works great on beer bottles if using a different technique shown on YouTube: Bottle Cutter Cutting a Beer Bottle Best Method Soldering Iron Stress greenpowerscience - https://www.youtube.com/watch?v=vZEE3tyDdoo&feature=iv&src_vid=sFXngPx3w3M&annotation_id=annotation_1526538171It uses a soldering iron and a cool damp cloth (I used a cool damp sponge.) A flashlight helps.This newer technique involves making a light score around the bottle with the cutter as before, then using a soldering iron to heat up a spot on the score and then wiping it with the cool cloth. This makes a small break along the score mark, much like the pour-over method only the crack starts small. You'll need the lighting just right to see the break which is where the flashlight comes in. After making the first break you then touch the iron to the line just ahead of the crack, leading the break around the bottle, wiping it down with the cool cloth every inch or so to keep the glass from getting too hot. A picture is worth a thousand words so I recommend checking out the video to get a better idea of it.It works like magic! Often the cut was so delicate and neat I needed to gently pull the two halves apart, like it had been cut in it's sleep and didn't know what had happened. I had 12 root beer bottles all of them came out great using the soldering iron! Even older children could do this with supervision.There are a few important notes about this technique.Beware teeny-tiny shards of glass. Lots of them. With most score-and-stress glass cutting methods like this one the glass sheds tiny shards around the score line. With the soldering iron method they aren't washed down the drain and instead hang around your work area, waiting to stab you in the thumb (actually happened to me.) Be *very* sure to wear safety goggles that entirely cover your eyes. I also highly recommend laying down a large towel to do all of your work on to catch the shards then wash the towel and the damp cloth you used separately from the rest of your laundry. Even keep your bottles over it until you're done sanding them and ready to wash them in the sink. And right afterward wipe off the floor if it's tile or hardwood or vacuum if it's carpet. And maybe wear heavy work gloves and wash them with the towel. And maybe wash your clothes with the towel too. Seriously, these glass shards are just *mean.*Lighter score lines usually make cleaner & faster breaks and produce fewer shards, but the break can also be more shallow if you don't apply heat long enough. Shallow breaks can give you a finished cut that's at an angle and/or chipping along the inside edge (needing more sanding), or funny looking cuts. Just keep the heat on long enough to get the break deep enough into the glass and wipe the bottle frequently to keep it cool.Use a light colored background. I used an old black t-shirt and had a very hard time seeing the fracture.Also a diamond grit nail file works great for sanding down the edges, even for the inside edge if you're careful. Plus it doesn't wear out nearly as fast as wet sand paper. Just keep it wet.And there you have it. I can't recommend the soldering iron technique enough. It was so easy, a lot of fun, and had great results!!!**Original review***First off, it needs to be said that cutting beer bottles using this type of bottle cutter is notoriously difficult, especially tinted bottles. Even if you do everything right, you will be very lucky to have a 20% success rate. I have read elsewhere that a 10% success rate is still very good. Mine was about 15%, so I was somewhere in the middle. Or 30% success if you count cuts that could be useable if you didn't need a completely crack-free edge.I got this to make items to sell on Etsy. I read the previous reviews and noticed how so many people where frustrated with it's lack of ability to cut accurately so I looked around online for tutorials. Found a great video on YouTube by GREENPOWERSCIENCE that helped a lot.With 21 bottles I had enough to compare the video's techniques of pouring scalding hot water over the cut then pouring cold water over the bottle to manufacturer's of plunging the cut section in hot water, then ice water, and back and forth as necessary. I only have a shallow sink in my apartment and also didn't want to get glass shards down the drain so I got a big plastic storage tub to do the pouring in, started some water heating, got my bottle cutter assembled, and went to work. With safety goggles on, of course!It was surprisingly easy to use the cutting tool. It looks like it should wobble all over the place, but after one pass where I didn't make a score around most of the bottle, I got the hang of it. I oiled the blade about every cut or two because the oil I had was a tiny bit heavier than I'd have liked. Making a score around the bottles was the easy part.The pour over technique worked better for me. The two great cuts I made where done using it.The odd thing was that about half my bottles just wouldn't crack with either method. I used the tapper that came with the cutter and nearly all of the breaks where curved or stars or even completely punched out so rather than continuing tapping around the bottle I used the hot/cold baths to finish then and got one more acceptable but not great cut out of it. I didn't have enough of these stubborn bottles to try the pour over method with them, so if somebody else tries it please leave a comment and let me know how it worked.So out of 21 bottles, I have two great clean and neat cuts and one OK one that was a little uneven but no cracks, with the only great cuts coming from the pour over method. There where about four cuts that where uneven or had a very small crack that would have been fine if they where, say, mounted into a light fixture that covers the cut but would never work as a vase or drinking cup.All in all I would not recommend this unless you *absolutely* can't use a wet saw. Using this score and break style of bottle cutting is tedious and the methods are difficult and the failure rate, especially with beer bottles, is just too high. If you regularly cut glass, tile, and/or stone and have the space for one, I recommend buying or renting a wet saw. There's a very good how to on instructables.com, look up "How to use a wet tile saw to cut glass bottles".Also, the instructions that came with the bottle cutter say to use the sand paper by laying it flat in a shallow bowl of water and grinding the bottle edge against it. I found that wore the grit off very quickly and tried just getting the paper wet front & back THEN laying it in the bowl. Worked like a charm!The most important part of this glass cutter is making sure the cutting edge is perpendicular to the bottle. take the time to zero the crossbars in, adjust the handle and make sure it is cutting at a 90 degree angle. Make a note where you are starting the score, and don't go over the score line again. Do one complete rotation and thats it. When submerging the bottle in the hot bath, submerge just to the score line, let it come to temp and then same thing for the cold bath. Just to the score line. My rate of vertical cracking has gone way down with this method.It's a great way to reuse bottles, just take the time to square it up and do it right.Thus far, I've only cut one bottle for one attempt. Can't complain, it's exactly what I expected it to be.The cutter is only going to do so much, using it properly and follow-up techniques are on the user. For my first bottle, I followed a video I had previously found online. The video talks about different methods, such as string and things like that. Even a cousin of mine had made their score with a cutter, then took a match and ran it on the outside of the score, followed by running ice along that. This produced uneven results and she struggled with getting some of them apart.After assembling the unit, which I found to be slightly confusing. The pictures point towards one thing while the directions are telling you different. Not to mention, the ruler markings are on the opposite side as displayed in the picture. Still not positive I have one of the washers with teeth on the right side, but it did the job, so I guess it is what it is. Shouldn't make that big of a difference anyways.One reviewer here states that you should only go around, score, once. I believe that to be true. As you can see in the picture I posted, there is a slight crack running down the far side, and an even smaller one on the front. These cracks are insubstantial and do not affect the integrity of the bottle. This was caused by me. I don't think I was applying enough pressure or really utilizing the blade on the first cut, so I went around, not too hard or deep, several times.Even after doing that, as you can see, the bottle cut was nearly perfect. I used the water technique, continuously switching between hot and cold and lightly pouring it over the score while turning the bottle. At first, the water was neither hot enough, nor cold enough. You really want to make sure you have both boiling hot water, and ice cold water. From there, gently pour over the score. Once the water was the proper temperature, the top just dropped right off. There was no explosion of glass, nothing forceful. It was super easy and I'm looking forward to cutting up some more bottles.I think once I get the hang of it, I shouldn't have any issues. Again, a light even score is all you need, one time around. If I find that thicker bottles give me issues, I plan on dunking it in hot water, and then in cold. For now, though, I'm greatly pleased with this product.I only gave it 4 stars because I found the assembly kind of confusing. I still set it up quickly, but just seemed weird. It should come assembled as far as I'm concerned.Hope this review helped. I'll keep you posted on future bottles.This is great and so easy to do the only problem i can see is you need to drink lots to get the bottles as once you get going on them you just want to keep on making them.Came with great directions, honest in advising practice could be required - in my case it did. Very pleased with this item.