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Bottle neck slides

I finally made a near perfect cut of a wine bottle neck using a jig and the hot/cold water technique. I'm wondering now about the best way to smooth the cut edge. I usually use a Dremmel with a grinding wheel but that is dangerous and gets fine glass dust everywhere including your lungs and eyes even though I use a mask and goggles.

Does anyone know if a propane torch gets hot enough to melt the cut edge so it will be smooth and rounded like commercially made glass slides are?

I Know I can just try it but I figure someone here has already.

Thanks for any suggestions.

Bluesheart

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Permalink Reply by Bama Hound on April 30, 2015 at 2:36am

I used a bench grinder with a fine stone on it, followed by a grinder with cloth wheels and jewelers rouge on them. Worked on and off of it for several hours. I went to use it a couple of days later, fumbled it and it hit the tile floor and splattered into about 3 pieces. I recommend a 3/4 or 11/16x 1/2' drive socket. They bounce and roll when dropped (;D)

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Permalink Reply by Goldsmithexile on April 30, 2015 at 10:06am

I used to work in a glass plant where we made toughened glass panels. The edges always had to be linished. We used special belt sanders, but with the addition of lots of water, thats what stops the glass particles getting in your lungs (lethal) and the abrasive cuts faster too with added water. You might get away with using a large brick or concrete block, again, with plenty of water, perhaps submerge it in a plastic bowl, rub the glass neck on it?

I'm guessing that the manufactured ones use a gas flame to heat the glass tube and then cut it rather than scoring and snapping? Unless they are made by casting in a mould? Does anyone know? They do have a good smooth finish though. I have a dunlop (213??) its my best one so far.

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Permalink Reply by John Sawyer on April 30, 2015 at 3:03pm

I use wet-dry sandpaper, 400 seems to work OK to dull any sharp edges. Propane may get hot enough, but you will need to anneal the glass or it will likely break when cooling.

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Permalink Reply by TN Twang on April 30, 2015 at 11:33pm

Glass dust is nasty--even with hand sanding.

I've had success using "emery cloth" from my local auto supply store. It's sold under various names, but it's sandpaper with some sort of "fabric" as a backing.

I am gonna' try working it under water (maybe in a 5-gallon plastic bucket). I really hate the thought of how much harm that dust can cause.

Please let us know if the propane torch works out. I don't own one, but it looks like a safer, tidier solution. Meanwhile, I've got 3 Dunlops and that's what I recommend to friends.

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Permalink Reply by John Sawyer on May 1, 2015 at 7:54am

Dunlops are good, I prefer the heavy walled slide... I have cut dozens of wine bottle necks, haven't cut myself yet, but definitely use some form of wet-dry in a bucket with a drop or two of dish soap...

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Permalink Reply by Goldsmithexile on May 1, 2015 at 8:24am

Maybe I am too hard on my slides, but I noticed there are hundreds of tiny dings on the outside of the glass wall after only 3 or 4 weeks of use. Is that usual? My diddley bow I use a lot has a wound string, maybe that doesnt help

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Permalink Reply by John Sawyer on May 1, 2015 at 8:39am

They do get scratched up over time. My Pyrex slide shows less wear than the bottle necks I have...

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Permalink Reply by Tom T on May 1, 2015 at 9:16am

I have a wet tile cutter that I used to make a number of bottle neck slides. No shortage of bottles around here. The diamond cutting wheel is constantly sprayed with water to keep it cool, so it is perfect for keeping glass dust down. Once cut, the wheel can be used to smooth the edges.

Now, while I can easily make bottle neck slides, I don't do it any more. The reason is simple: Good Dunlop pyrex slides are available from Sweetwater (and others) for around $3.50 with free shipping. For that kind of money, I'm better to buy than take the time to cut and smooth a bottle neck. Also, I've found that the Dunlops are smoother and harder than bottle necks and play better.

From a quality/cost point of view, it's hard to beat these pre-made slides.

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Permalink Reply by TN Twang on May 1, 2015 at 9:51am

Thanks for the tip, Tom T.

$3.50 (actually $3.79) is a better deal than the trouble I'm putting in. I could re-sell those for $4 and be ahead of the game. I only provide slides because you need 'em to play fretless guitars. I get no fun out of making them.

I do need real "broken" bottles for my own playing though. It's part of the mystique that impresses people.

It has occurred to me that selling broken glass to people could incur some liability if anyone managed to harm themselves.