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polishing glass

Posted by gail  
Re: polishing glass
January 06, 2009 02:30AM
Hi everyone!
I just accidentally found your blog discussing polishing beach glass.
New to this. I have a new tumbler (never have used it...not sure what to do)
I would like to just put some shine on the beachglass I have found. Any EASY and relatively
simple ways to do this?
Thanks for your help.
Rock Polishing
Re: polishing glass
February 13, 2009 05:30PM
If you check out my rock polishing blog, you'll find all the answers u need there
Re: polishing glass
January 27, 2010 01:58PM
Please anyone can tell me what are the steps of polishing glass beads?
I'm using polishing machine which is simply rocking rubber wheel i need to know what are the steps of polishing and what are the chemicals used in polishing in every step the right quantities to be used. should I add any smaller size round beads to give round effect as a result?
please any good information or advice will be appreciated
Re: polishing glass
January 27, 2010 01:59PM
Please anyone can tell me what are the steps of polishing glass beads?
I'm using polishing machine which is simply rocking rubber wheel i need to know what are the steps of polishing and what are the chemicals used in polishing in every step the right quantities to be used. should I add any smaller size round beads to give round effect as a result?
please any good information or advice will be appreciated
avatar Re: polishing glass
January 30, 2010 04:10PM
The best way to polish the glass in the final stage is to add in plastic pellets and use optical grade cerium oxide as it is the best polishing medium for glass. The key is you also want to have a nice smooth pre-polish on the material before going into the polishing stage.

Registered Gemologist
Research Gemologist
Club President/Owner
Re: polishing glass rock sanding and polishing
April 26, 2010 06:42PM

Bought a 60lb plus piece of glass rock. It is leftover glass from windows, they sell to tourists. Want to sand it up and polish it, and set it by my swimming pool.

Any advice ? We have been using a drummel with a fine stone for the edges and a sandpaper tip for the surface. Seems to scratch it up. HELP!

Thanks, Heidi
avatar Re: polishing glass
April 30, 2010 05:35PM
As you have seen, if you ask 50 people the best way to tumble polish you will likely get 50 different answers. Tumbling is an art and everybody has found a way that works best for them, so it is a matter of experimenting and finding what works best for what you are trying to polish. I finally found a recipe from someone that was an old hand at tumbling. I tried a dozen things to tumble obsidian and never could get a good polish until I tried using: ground corncob, broken tempered safety glass with a few shavings of Ivory Bar soap on the final stage. I do the first 3 steps as you would anything else. I start the broken safety glass (the stuff you get when someone breaks you brand new patio sliding glass door with a baseball smiling smiley), in the first step and keep it all the way to the end, adding more after the first and second step to keep the volume up. It breaks in nice size angular pieces and works great as a tumbling media. The hardness is just slightly harder than most glass so is durable without beating up the glass. I actually use it instead of plastic pellets, which I hate, even with agate. I put enough ground corncobs to make a thick mushy slurry. You can experiment with the amount depending on your type and size of your tumbler. The corncob works well as a carrier for the polish and as a cushion to keep the glass from banging and chattering against each other. One of the most important things, especially with a rotary tumbler is to keep the barrel about 3/4 full. If the volume is to low you don't get enough interaction and the glass has too much space to bang against itself. I sometimes will do a final burnishing step with just fresh corncob, the safety glass and Ivory soap if needed. I hope I have helped and not added to the confusion. If you have any more questions you can send a PM or ask here. Good luck
avatar Re: polishing glass
April 30, 2010 07:33PM
I forgot to answer a question posed by Rock earlier about polishing glass with HF. I have always had a love of glass and use to cut and polish slag glass into various obliques shapes and thought about trying to use HF for the polish. Many years ago I visited several glass cutting factories in Ireland and found that virtually all if not all of the leaded glass pieces manufactured these days is acid polished. I think it is a shame because it lacks the really fine sparkle that the old pieces had which were hand polished. I asked at several factories and as expected they are secretive of the exact process but I found out that the always first run the pieces through a Sulfuric Acid bath to remove any oils or other contaminates. They wouldn't tell me the concentrations of the acids used but I was told that Acid polishing with HF only works if there is a sufficient percentage of lead oxide which I think is above 20% but I don't remember. Before I knew this I had a brilliant idea of using HF to polish Apache Tears but it wasn't that brilliant. It produced an a tektite look alike which was interesting but not polished. I don't think I ever tried HF on my slag glass. If I did it didn't work because I stuck with my original method. Being a geochemist I have worked with lots of acids and I would not recommend using HF to anyone that is not trained and very experienced with chemicals. It is the one I treat with the UTMOST care. It is very nasty and dangerous.
Re: polishing glass
August 04, 2010 02:04PM
Another good site on rock polishing is

Rock Polishing Wrote:
> If you check out my rock polishing blog, you'll
> find all the answers u need there
avatar Re: polishing glass
August 05, 2010 04:24AM
I almost forgot, another method to polish glass, is of course, flame polishing. Not as good as a well done lapidary polish IMHO, but still works nicely and is much easier, and faster as well, to do.

Registered Gemologist
Research Gemologist
Club President/Owner
Re: polishing glass
April 11, 2012 06:21PM
Hi fellow glass inthusiests,
My inquiry is: I do art and would like to do a glass mosaic on a French Glass Dividing Wall I have between my kitchen and living room. I have not worked with to much glass when it comes to art but I have broken up colored glass pieces(from bottles, vases, etc.). I do not own a tumbler to smooth out my broken glass and it is far to much work to individually sand hundreds of small pieces with sand paper. I dont have an oven to heat up to 2100 degrees or what have you. I have a blow torch, oven, microwave, somewhat regular household items. I want to do it right, but when the muse calls, I like to jump into it. Any suggestions other then to go out and buy what I need. I just want to round off edges on broken glass without taking 100 years to do so!
Thx- Jennifer
Re: polishing glass
June 05, 2012 07:57PM
Let me get this straight.

You do not want to individually grind and polish each piece.

You do not want to buy a tumbler.

You want it done right, and right now, without wasting any time.

May I suggest trying magic?

If that doesn't work, make a very modest investment in a decent tumbler and range of grits. It really is a very, very simple process, and glass is soft so it won't take that long.

This website has everything you'll ever need to know about tumbling:
Re: polishing glass
June 05, 2012 09:35PM
If all you want is to avoid being cut by slightly rounding off the edges of the glass shards, you could try putting the glass pieces in boiling water for some time.
This is supposedly rounding off the edges by dissolution of the glass.
Maybe add some baking soda, as alkaline solutions will speed up the dissolution.

I've seen that in a TV science show many years ago.
It was said to be a technique occasionally used by people who show off walking on glass sherds with their naked feet.

The look of the glass sherds is basically unaffected.
So this is no replacement for tumbling.
You might give it a try.
I have not tried it myself, so don't ask me for details.
Linda Carnicelli
Re: polishing glass
February 19, 2013 09:38PM
I have some blueberry quartz beads that need to be polished to give me a nice shine on them. any suggestions?
avatar Re: polishing glass
February 20, 2013 09:01AM
I am not familiar with "blueberry quartz". Could you post a picture of them or tell us something of their origin? Are you sure the material is quartz?

Rock Currier
Crystals not pistols.
Barb Murrin
Re: polishing glass
May 02, 2014 03:30AM
I'm also interested in being able to smooth out glass edges for mosaic use. (Think it would be a good way to use up glass scraps that would otherwise be discarded.) A couple of questions:

- What tumbler would you recommend for this?
- Ground corncobs - Do you let the cobs dry and then grind them up somehow, or can you buy them ground and ready to go? If you grind them yourself, how do you go about it?

Thank you for your assistance.

avatar Re: polishing glass
May 02, 2014 01:27PM
How large are the glass pieces you want to "round"? If they are too large, putting them in a tumbler will cause them to break and chip each other. Putting ground up corn cobs in the tumbler will "cushon" them from bashing against each other to some extent. If you are going to round them you will have to put in an abrasive media that will grind away the sharp edges, but it will also dull the shiny surface of the glass and leave you with a mate finish. To get them shiny again? you will need to use progressively finer grits and finally a polishing powder, being careful to clean them and your tumbler between each step to make sure that you remove all the abrasive media from the previous step. Glass is real easy to work with. I might suggest you use a sanding disk and you manually sand the edges a little bit to break the sharp edges, if that is what you want. If you need the edges polished, you can pretty easily polish it using a leather or felt buff and something like tin oxide or aluminium oxide after a quick once over with 600 grit paper. Depending on the degree of roundness you want you might even be able to break the edges enough with a 600 grit disk.

Rock Currier
Crystals not pistols.
Re: polishing glass
January 09, 2016 06:26PM
Water diluted Hydroflouric acid along with Sulphuric acid in the right proportions is excellent for polishing glass but is EXTREMELY dangerous. Anyone using it should wear fully protective gear and work outdoors - with double gloves. Check the forums and you will read of fatalities with small amounts getting on the skin. Do not attempt to use it if you do not first purchase Calgonate (Calcium Gluconate) for First Aid. It does not just give you a skin burn. Once on the skin it invisibly travels deep to the bones and alters hour body calcium levels leading to a heart attack. Spill a cupful in your arm or leg can be fatal - not straight away - and even if you jump immediately into a swimming pool or run a bath to soak in it. It is now illegal to either purchase or store HF in the UK without a license. I am still working on an alternative lapidary means of gaining a highly polished finish. Unless I can find one my days of glass polishing are now over.

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