I have this beautiful antique kerosene lamp. When they moulded the lamp they left a little rim of glass going around the middle of the finger grip.
This little rim sticks up about 1/16 of an inch. It digs into your finger when you hold the lamp.
I am a carpenter not a glass worker I don't know how to fix it.

Is there some kind of round file that I can use to grind down this little rim?
I just tried my ceramic stick knife sharpener, it doesn't work.

I’d think a diamond file.

Glass is made up from sand so i think some fine paper might wear it down.

A little at a time.Grits i have no clue about but it's worth a try.

Use a variable speed Dremel tool and a diamond dust coated burr. Slow speed, gentle pressure, and don't let the heat build up. Getting the glass hot will make it crack. Doing the cut under a slow stream of lukewarm water in the kitchen sink might be a good idea.
Jerry

Wet sand with wet/dry paper. Start with 80 or 100 grit and work up.

I’d leave it as it is, mold line helps to validate authenticity. Additionally, it will have to be polished after being removed or it will look worse than it feels now.
If you must, Aluminum Oxide backed sandpaper will do the job.

A coarse diamond file. You will have many uses for it later, sharpening hoes, shovels, lawn mower blades...

10 bucks at Amazon



John

Slowly..
There is some sort of abrasive paste they use for grinding lenses...
It might be enough to soften the edge a bit..

It can be done with a Dremel tool and tungsten bits, but it should be done in water.

Vibrating sander, do it all the time for table top edges not a big deal... 400 grit + or -

I’d try the dremel approach with a small drum sanding attachment.

That, keep it cool.

Do as HRL suggests.

Don't sand it, don't grind it. Instead, take a propane or MAPP gas torch (a mini torch would work perfect) and heat it until the glass starts to melt - it will smooth right out. It should only take about 15-30 seconds of direct heat. Then cut the flame and let it cool naturally at room temperature. Seriously, it will work like a charm.

That's how we "polished" the ends of glass rod and tubing in the chemistry lab, except we usually used alcohol burners instead of torches.

Glass edges (glass panes) are normally ground with diamond wheels at high speed water cooled. However you can easily de-burr an edge like that with a Dremel and small sanding drum just keep it moving as to build up little to no heat. Emery cloth will likewise knock that edge off wrap it around a flat tool like a file and knock the burrs off. probably no need to use too coarse a grit work down and polish if needed. worked in the glass industry 3 1/2 decades.

A Dremel with a round burr or stone is your friend.

That’s the first thing I thought of as well.

Wouldn’t this subject the glass to severe thermal shock?

You can heat it up but the chance a piece like that could have a small defect in it is pretty high and could easily break or shatter hardly worth the effort. Just sand file or grind it in a careful manner it will only take a few minutes....

Yes it would.

My wife does art glass. For this, she'd use a Dremel and a diamond bit. KEEP IT WET or it'll overheat and could shatter. A 2d person constantly squirting water on it is all you need.

It WILL work, I promise. I can do it quicker, and better that way in less time than it would take me to set up my Dremel.

Only if you dunk it in water to cool it. It's how it's done every day in chemistry labs throughout the world.
Do you think I pulled this method out of my a$$?

Maybe...........

Huge difference in the thermal properties of the borosilicate and quartz glassware used in modern chemistry laboratories and the glass used in 19th Century decorative glassware.

Before you put that kind of heat on it, you'd better know what you're doing. You could shatter the handle. A little touch up with a wet diamond grinder is quick, easy, and safe.

This is likely soda lime glass - plain, ordinary, glass.

Laboratory glass is borosilicate glass and has much better thermal shock resistance.

The lamp will almost certainly crack/shatter with the application of a torch.

As best I can figure this lamp was made about 1890. It says on the glass ACME trade mark LEAD-FLINT. I think they added lead and flint to the glass in those days.
Also says MADE IN THE US of AMERICA.

I'd side with leaving as is. The grind is the easy part. Polishing even with the surrounding terrain is the challenge.

The sharp edge is inside the top of the handle. There wouldn't be any need to polish it unless it has a high collector value. Just smooth off the sharp ridge a little.

I would try polishing with cerium oxide polishing compound. This is what glass working shops and mirror plants use. Keep the glass wet with the polishing compound and take your time, it will work fine, put a torch on 1890s glass and it will probably explode. Amazon has cerium oxide powder.

I'm not an expert but I worked in the mirror industry as a chemist for a while. Cerium Oxide actually has a solvent effect on glass.

What Cal-H said. Cerium oxide is the paste/abrasive I was thinking of....

Having cracked more than one item trying to heat polish a sharp edge thinking I could treat it like lab glass. I would stay away from the torch. Differential heating is a pain in the tookis.. and the more complex the shape, the harder to control predict. Just when you think you did ok it starts to cool and then craack... whoops

Don't effing polish it! Just hit it with a torch for 20 seconds and you're done!

You could wear gloves if it hurts that much.

Thanks for all the advice.
I am a log builder I have thousands of dollars of tools. I have 2 of the 7 inch disc grinders, a DeWalt and a Makita. I have a real nice Makita belt sander. All kinds of expensive drills etc etc.
But I don't have a dremel tool. Never used one.




I went down to Lowes and bought this dremel grinding stone for $3.50. It fit right in to my DeWalt cordless drill.




This thing worked great! I knocked out that little rim in about 7 minutes.

Thanks for all the advice. I did buy some 80 grit and 120 grit sandpaper and was going to wrap it around the ramrod to my Kentucky rifle, and duct tape it on. But it didn't come to that the home-made dremel tool did the job. Easy.