Timescales and grit preferences for tumbling glass to a mirror finish

[mick]

Hello Everyone,

I did a brief search and could not find the answer to my question so thought i would ask it.

I have been experimenting recently with seaglass and getting it down to a mirror finish. The results i have achieved are good but by no means sell able in my eyes. I know the very process of polishing is debatable as its no longer a nature polished it but we are going to incorporate it with gold so i feel it has to shine.

I have been starting with the 400 grit for 1-2 days then moving on to zinc oxide for roughly the same time. I have tried longer on the polish stage too (4 days) and it does not seem to make any difference sadly as i always get a blueish sheen to the finished items which is even more prevalent i dare say after longer polish.

I currently have some stones in at 80 grit and i am planning to run them for 48 hrs then through 2 more stages to see if it helps but anyone's experience would be excellent as its a long drawn out process to prove your best settings.

Why am i getting a bluish shine on the items? Is it because they need longer at 400 grit first, do they need another stage at perhaps 1200? Any advice would be very much appreciated.




Thanks
Mick

[Dennis]

When tumbling glass you will at best get a fine satin finish.

If you want it glossy, you need to polish with increments of diamond grit, or melt the surface,.

A lens grinders, lapidary, or lamp workers forum would help you more. Dennis.

[CJ57]

Just my thoughts from a buyer point of view.
The natural sand blasted quality of sea glass would be the reason people/I would buy it no matter how it's mounted.
If it's polished I would feel that it was just a piece of polished glass set in gold and it probably wouldn't be thought of as sea glass without its natural qualities.
If it's still the route you want to take then lampworkers as Dennis said will have the expertise with glass to get the finish you want.

[mick]

When tumbling glass you will at best get a fine satin finish.

If you want it glossy, you need to polish with increments of diamond grit, or melt the surface,.

A lens grinders, lapidary, or lamp workers forum would help you more. Dennis.

Thankyou for the information. My friend is a former optics grinder and said they used a special polish to finish them off. If we have to go down that road so be it but its £80 a kg. Do you think it is possible to get a better finish tumbling if we go down the road of using better quality polish such as the lens polishing powder?

Thanks
Mick

[mick]

Just my thoughts from a buyer point of view.
The natural sand blasted quality of sea glass would be the reason people/I would buy it no matter how it's mounted.
If it's polished I would feel that it was just a piece of polished glass set in gold and it probably wouldn't be thought of as sea glass without its natural qualities.
If it's still the route you want to take then lampworkers as Dennis said will have the expertise with glass to get the finish you want.

Yes your right it does remove some of the natural charm but we a trying to keep some of the natural look but achieve a better shine. I will post a few pictures now of some of the glass we have which i feel deserves a better finish to show it off.

Thanks
Mick

[mick]

10991

10992

10993

10994

10995

Here is some examples :)

[mick]

https://www.dropbox.com/s/8m7p0lg5zp95zle/DSC_0975.JPG?dl=0

https://www.dropbox.com/s/b0f4mqoemouaem5/DSC_0977.JPG?dl=0

https://www.dropbox.com/s/8hr4sv6hlsywrbw/DSC_0978.JPG?dl=0

Here is some examples of the finish we are getting so far. The zinc oxide is still not full taken off.

[CJ57]

I completely get that. I love glass and the play of light but it becomes what glassblowers or lampworkers produce in the workshop when highly polished. What draws me you to sea glass is the history and the nature involved and the reason you maybe picked it up in the first place. Of course that's one persons view but given the possible costs of polishing to the high standard as your friend suggests it might be more cost effective to make your own or take advice from glass workers, I'm not sure that you'd get a return on your costs. I'll have to do a search on sea glass jewellery and see what's in offer:)

[mick]

I completely get that. I love glass and the play of light but it becomes what glassblowers or lampworkers produce in the workshop when highly polished. What draws me you to sea glass is the history and the nature involved and the reason you maybe picked it up in the first place. Of course that's one persons view but given the possible costs of polishing to the high standard as your friend suggests it might be more cost effective to make your own or take advice from glass workers, I'm not sure that you'd get a return on your costs. I'll have to do a search on sea glass jewellery and see what's in offer:)

I have just had a chat with a polishing company and apparently zinc oxide is the worst polish for the job as glass is too hard and they recommended cerium oxide. A little more pricey but all the other grits are cheap enough so i could definitely see a profit margin if this works. I will order some and see how it turns out :)

[china]

I am no authority on glass, but I have friends who tumble their stone for at least a week for each grit

[mick]

I am no authority on glass, but I have friends who tumble their stone for at least a week for each grit

Thats why i was asking on here, the timescales online vary wildly but we are running a batch for a very long spell now to see how it turns out

I am hoping it was the low quality of the zinc oxide that caused our issues and the next batch we run turns out exactly how we want. We are not trying to take all the natural marks away but more trying to let the surface shine.