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Tips for finishing cut bottles Answered

I bought my boyfriend a Kinkajou Bottle Cutter and Bottle Cutting Inc. sandpaper kit because he was interested in recycling bottles into drinking glasses, candles, etc. He was really excited about the handmade gifts he planned to make, but the sanding/ finishing of the bottle rim has turned out to be such a laborious process he's only finished one glass in 6 months. The sanding papers range from 80grit to 220, I believe. It just takes so long to get a nice smooth edge that your arm is killing you and it's difficult not to give up before achieving a truly professional result.
Anyone out there have tips or tricks to make the finishing process faster or less tiresome? Any secret tools of the trade we should know about?  We don't have a garage or big power tools to work with, though I've considered seeing if maybe there's something we could rent for a day(?) I've also looked into BC inch's new "diamond' sanding pads but we're hesitant to drop more money into the project unless we hear those are totally amazing.
I welcome your thoughts!


you could try putting the bottle in a drill and spin it while holding the abrasive paper on it

I've been thinking about this, and I don't think it would work, but I do think you might be on the right track. Some way of turning the bottle while holding the sandpaper/diamond file on it might make it faster and easier. But there has to be water running over it at the same time, and it would have to be kept very steady and at a consistent speed...

The water is only required for your own health as otherwise you have the fine glass dust in your lungs ;)
A vacuum cleaner with a fine dust filter (or better a ducted one) will do just fine here, but water is much easier.
The trick of turning the piece you are working on is really old but not really necessary.
It is not like working with wood where you can take off a lot of material at once, with glass we are really only talking about fractions of a mm at a time.
A little bump from the cutting will disappear very quick, but once falt with the material around it you will take hours for every mm more.
Biggest problem when turning the workpiece would be to actually get an even result. After all it does not work like a lathe ;)

This is just a guess, but you might also be able to use a Dremel, with a diamond/carbide bit. It might be a little easier on the hands, and it's not terribly expensive to buy if you don't already have one.

I had wondered about that myself. I'm guessing it takes a little practice but it makes total sense that it should work, maybe with the finest grit sanding afterward. The video is a little deceptive. I knew it would take longer than that, but based on our experience so far I have no idea how anyone can make any volume of glasses using the abrasive paper alone!

A dremel works but unless you don't care about an even finnish I would not use it.
You simply can't get a diamond tool for them that is big enough.
Trust me, once you tried a diamond sharpening block with running water you won't go back to anything else.
The big ones with 4 sides from 200 to 600 grid are perfect fot the job (and cheap).

Thanks for the tip Downunder. Like I said, I was just guessing. I've never done anything like this. I can vaguely remember seeing it being done by someone, somewhere, somewhen... probably late '70's, maybe a family friend... I just can't quite get the memory to come back all the way.

I just watched the how-to video for the Kinkajou. The guy in the video makes it look like you can do the whole thing start to finish in 5 mins. Of course, he is trying to sell the product, so he isn't going to say that it takes so long your arm just about falls off before you're done.

Thank you for posting this. I have an old bottle cutter around here somewhere that I never used because I didn't really know how. It was given to me by someone who bought it at a Goodwill store and it didn't come with any directions. And that was before you could find everything you ever wanted to know online. Now that I have an idea of how it works maybe I'll dust it off and give it a try.


2 years ago

I'm so glad you asked because I can really use the answers myself!

Diamond file or diamond sharpening block / stone.
Only a few bucks in the hardware section of your home improvement shop.
Sandpaper is a useless task unless it is designed to work with glass.
Glass is about the same hardness than what the sandpaper has to offer - so there is little to no abresion happening.
I fix the rim of a thick bottle with a diamond file in less than 15 minutes.
If you want a more glossy finnish simply put some clear acrylic paint over the sanded areas.

Thanks for the suggestion --good to know diamond files can be found locally. We aren't using regular sandpaper. I mis-spoke there. It is silicone carbide abrasive paper sold specifically for use sanding the glass bottles. It just takes FOREVER!

I know what you mean by forever.
The main problem is getting it done without cramps in your hands LOL
If you can't find a diamond file check the diamond sharpeners, go for biggest ones and something small.
I have a 4-sided block from 200 to 600 grid, was about 15 bucks.
For the finer corners or other details I use a diamond fishing hook sharpener, 3 bucks off Ebay.
Just make sure you work with plenty of water, I prefer the bath tub with a slight stream of water on the work area - a shopping board works wonders here ;)
If you have trouble finding a diamond file ask at local metal shops, if they deal with hardened steel they should have them, you might be lucky and get an old one for free.