Aussie Lapidary Forum

LAPIDARY => Gemstone Faceting => Topic started by: MakkyBrown on January 26, 2019, 10:26:00 AM

Title: TV glass toxicity?
Post by: MakkyBrown on January 26, 2019, 10:26:00 AM
I've got a huge amount of test cutting to do and thought TV glass would be good. Soft with a reasonably high RI. Just the thing for quick nasty faceting.

So I dragged the big old 90cm CRTV out of the bottom room, pulled it to bits, removed the vacuum, put contact film on the screen(left over from the kids school books), covered with a towel and carpet tiles. Then gave it a good wack with the sledge hammer. The shattering radiated nicely from the impact point and in no time at all I had a bucket full of glass ready from faceting  ;D .

Cubed a few bits by hand on the saw, but then....
Hmm, I got thinking about lead :o and hmm ??? though it might not be a good idea. So I did some reading and luckily the glass from the screen fronts is usually fairly low in lead. The screen glass I have has a light grey tint to it.
So the question is has anyone here got exp with tv glass?? Is it safe for me to facet it. It was from one of the last models produced (about 2004 Panasonic). I realized the tube glass is very high in lead, I'm hoping the screen glass might be ok. I've read screen glass for colour tv's was commonly lead free barium/strontium glass.
CheersMB
Title: Re: TV glass toxicity?
Post by: MALACHI on January 27, 2019, 08:36:35 AM
Hi Makky. I'm glad you bought this post up. At my club we have available some TV glass that's from an old Black and White tv. This glass most definitely has lead in it and a result of this was a much higher RI. Fortunately up to date not many people have been using it! But my thoughts on this is that there is minimum contact with residue from cutting except when wiping the stone when checking cut and when cleaning down the machine. Though one would need to wash hands after as a precaution.   Cheers
Malachi  beers
Title: Re: TV glass toxicity?
Post by: MakkyBrown on January 27, 2019, 09:43:13 AM
Hi mate,
Lead is nasty as it bio-accumulates and I'm pretty sure through skin contact aswell. I think glass locks it in a bit but the fine grinding involved with faceting I would be wearing gloves for lead glass. Then you have the risk from the powder/dust when the laps dry.
I wouldn't use it especially if there are kids at the club. Happy to send you some of hopefully safer glass I have for the club to use, it's just got a grey tint to it but I reckon the RI is pretty high looking at it.
CheersMB





Title: Re: TV glass toxicity?
Post by: MALACHI on January 27, 2019, 08:42:14 PM
We only use Quartz when learning. The glass is there and handy if anyone wishes to use it, but because of the realization its hazard, I'll be suggesting its disposal asp. Thanks for the offer on the glass Makky, but I think we'll be okay with Quartz. Cheers!  beers

PS On another note. I hope your not being too affected by the smoke and fires there in Tassie.

Malachi  beers
Title: Re: TV glass toxicity?
Post by: MakkyBrown on January 27, 2019, 09:08:56 PM
We only use Quartz when learning. The glass is there and handy if anyone wishes to use it, but because of the realization its hazard, I'll be suggesting its disposal asp. Thanks for the offer on the glass Makky, but I think we'll be okay with Quartz. Cheers!  beers

PS On another note. I hope your not being too affected by the smoke and fires there in Tassie.

Malachi  beers
Smoke is not too bad atm it comes and goes. Street lights were on in the middle of the day the other day. We've been sealed up in the house with the aircon going to filter it. :)Just dopped up some of the tv glass to give it a go. Quartz or topaz cut nice stones and I just can't bring myself to faceted it without care or a perfect polish etc hence the tv glass.
CheersMB


Title: Re: TV glass toxicity?
Post by: MALACHI on January 28, 2019, 09:49:39 AM
 I've recently had a break of over a year and half from faceting, so I too have been holding off cutting some of my better stones.  I'm slowly but confidently, getting back into cutting Brilliants again. Eventually, I want to have a go at some Hearts that turn out very nicely on Citrine.  ;)  ;)
Malachi  beers
PS I do feel sorry for all those there in Tassie, that have breathing related medical conditions. It must be really tough for them. I hope the fires are extinguished quickly.
Title: Re: TV glass toxicity?
Post by: gypsygurl on February 05, 2019, 01:53:55 PM
Hello everyone, as a newbie to the world of gems and minerals and I've recently joined a lapidary group. I thank you for this valuable information, as I had no idea about the lead content. As I'm looking into purchasing a faceting machine and was going to practice on old tv glass. Think i will be finding something else that has a high RI. Thankyou once again
Title: Re: TV glass toxicity?
Post by: Rusted on February 05, 2019, 02:39:23 PM
Welcome gypsygurl
If you want natural materials, Quartz is popular with beginners, though it can be a pain to get a good polish with diamond laps, be prepared to use cerium oxide or tin oxide to get a nice polish. Some of the clear feldspars are good forgiving materials for beginners, eg. Labradorite from Springsure.
Cubic Zirconia is really sparkly and usually cuts well and is really cheap .25 cents a carat last time I bought it. Man made Spinel and corundum are similar prices and cut well.
Title: Re: TV glass toxicity?
Post by: MakkyBrown on February 05, 2019, 03:25:42 PM
Hello everyone, as a newbie to the world of gems and minerals and I've recently joined a lapidary group. I thank you for this valuable information, as I had no idea about the lead content. As I'm looking into purchasing a faceting machine and was going to practice on old tv glass. Think i will be finding something else that has a high RI. Thankyou once again
Just lost my reply to a 403 error :(,
The short version, welcome :). TV glass is ok if colour tv and front screen glass only. Should have a tint to it. Beach glass can also be nice, ri is lower but will the right angles can look really nice.
(http://aussielapidaryforum.com/forum/gallery/8/medium_5704-180517214855.jpeg) (http://aussielapidaryforum.com/forum/index.php?action=gallery;sa=view;id=8575)
Title: Re: TV glass toxicity?
Post by: gypsygurl on February 05, 2019, 03:31:51 PM
Thankyou Rusted.
Yes, I am currently learning on my 1st piece of quartz & am having a few issues with polishing, I never thought of using cerium oxide or tin oxide. My teacher hasn't mentioned it either from memory, but I'm very interested in trying different mediums to get the best polish. I will purchase some of both to see what my surfaces are like on stones i will eventually facet at home. Thankyou for all the other information, I will keep an eye out at the local Rockarama coming up in May 2019 to purchase rough & ask at my local club to see if we have some rough of what you have mentioned. I love faceting it's incredibly refreshing and relaxing
Title: Re: TV glass toxicity?
Post by: gypsygurl on February 05, 2019, 03:40:21 PM
Thank you MakkyBrown.
I will keep that in mind.
What material is those pretty round brilliants?
I know at our club they said they have heaps of the old really thick tv glass and how well it shines, got me intrigued and was going to be my cheap practicing material. I have alot of beautiful beach glass and old coloured glass fragments ive picked up along my travels, will definitely be trying some pieces.
Title: Re: TV glass toxicity?
Post by: Rusted on February 05, 2019, 06:21:41 PM
A good lap for using with cerium or tin can be easily made from draughting film, it's like tracing paper only not paper, art supply places and office supplies have it. Mark and cut a 6 inch circle and cut a hole in the centre, use on top of any old worn out or contaminated lap, if you can find an old lucite or copper lap that is ideal, a drop of sewing machine oil will hold the film to the lap. The good thing with the draughting paper film is that it comes in huge sheets, so dozens of laps from one sheet, when it gets contaminated or worn just replace it.
I use cerium and tin in a little eye dropper bottle but at my club they mix it to a very watery suspension and spray it from a spray bottle.
Title: Re: TV glass toxicity?
Post by: MakkyBrown on February 05, 2019, 07:16:35 PM
Thank you MakkyBrown.
I will keep that in mind.
What material is those pretty round brilliants?
I know at our club they said they have heaps of the old really thick tv glass and how well it shines, got me intrigued and was going to be my cheap practicing material. I have alot of beautiful beach glass and old coloured glass fragments ive picked up along my travels, will definitely be trying some pieces.
It's beach glass, I was just showing you glass can look nice and 100+ year old beach glass is pretty cool imo. Not worth a lot, but nice colours. Here is the photo of the other 2 bits, I cut what would have been the stopper top into 4. Just need to avoid bits with bubbles in the glass,
(http://aussielapidaryforum.com/forum/gallery/8/medium_5704-210517124205.jpeg) (http://aussielapidaryforum.com/forum/index.php?action=gallery;sa=view;id=8577)
Title: Re: TV glass toxicity?
Post by: Ghost on February 05, 2019, 08:31:31 PM
Cut 3 very nice stones from TV glass and haven't died yet, despite the Avatar name.

Regards,
Ghost.
Title: Re: TV glass toxicity?
Post by: FlashGP on February 06, 2019, 08:39:45 AM
Hi all,

I wouldn't be too concerned about the lead in TV glass if you take basic precautions, just as you would with say tigereye or quartz.

The lead is trapped in the silica matrix in the glass. That's why good crystal glasses are safe to drink from.  Orefors crystal glasses come in 2 grades, 16% and 24% lead.  I would have thought TV glass to br fairly heavy with lead to stop Xrays leaving the TV.

If crystal dust is a problem, clean up better, silicosis is likely to be a bigger concern.  All our gem material contains silica, and our lapiddary processes produce fine particles with sharp edges.

Happy faceting.
Title: Re: TV glass toxicity?
Post by: MakkyBrown on February 06, 2019, 06:01:43 PM
Cut 3 very nice stones from TV glass and haven't died yet, despite the Avatar name.

Regards,
Ghost.
I reckon you'd be pretty safe with 3 stones. I think it's more of a long term thing where it accumulates. I was reading one study measuring the rates of leaching out of different types of tv glass as there are concerns about it in land fill. Cutting or grinding the glass would have to increase the rate. Could just wear a glove but I'm not going to cut leaded glass myself.

Title: Re: TV glass toxicity?
Post by: Rusted on February 06, 2019, 08:21:38 PM
I don't think I would be all that worried about faceting lead glass, really how much contact do you have with the lead glass or its slurry when faceting.
I have seen some interesting stones cut from Uranium glass, I don't reckon I would do it though,  that's a bit risky. Swallow a speck of that and you might have Alpha particles zapping through your body, nah.
Title: Re: TV glass toxicity?
Post by: MakkyBrown on February 06, 2019, 10:33:11 PM
lol, I didn't even know there was uranium glass. So google it..once made into tableware.

https://en.wikipedia.org/wiki/Uranium_glass
Title: Re: TV glass toxicity?
Post by: Rusted on February 07, 2019, 05:51:58 AM
It's pretty stuff but apart from glowing it doesn't do much, quite popular with collectors.
Title: Re: TV glass toxicity?
Post by: FlashGP on February 08, 2019, 07:11:34 PM
I don't think I would be all that worried about faceting lead glass, really how much contact do you have with the lead glass or its slurry when faceting.
I have seen some interesting stones cut from Uranium glass, I don't reckon I would do it though,  that's a bit risky. Swallow a speck of that and you might have Alpha particles zapping through your body, nah.

What are you worried about, our new airconditioner and ozone generators basically generate them as antibacterial agents.  Alpha particles are generally hydrogen irons wizzing through the air instead of being in solution.  They don't last long.

Its the heavy metal poisoning from uranium that is worse.
Title: Re: TV glass toxicity?
Post by: Ghost on February 08, 2019, 08:16:55 PM
Uranium decays into lead eventually.
So after quite a few billion years you will die of lead poisoning anyway.
Title: Re: TV glass toxicity?
Post by: Orange Pirate on February 08, 2019, 10:12:15 PM
I don't think I would be all that worried about faceting lead glass, really how much contact do you have with the lead glass or its slurry when faceting. I have seen some interesting stones cut from Uranium glass, I don't reckon I would do it though,  that's a bit risky. Swallow a speck of that and you might have Alpha particles zapping through your body, nah.
What are you worried about, our new airconditioner and ozone generators basically generate them as antibacterial agents.  Alpha particles are generally hydrogen irons wizzing through the air instead of being in solution.  They don't last long.Its the heavy metal poisoning from uranium that is worse.



Mmmmm. That sounds like a modern day something they said to the Radium girls.
For MB  ;) https://en.wikipedia.org/wiki/Radium_Girls
Title: Re: TV glass toxicity?
Post by: MakkyBrown on February 10, 2019, 08:43:07 AM
Thanks OP, a sad tale.
Title: Re: TV glass toxicity?
Post by: Orange Pirate on February 10, 2019, 01:46:11 PM
Thanks OP, a sad tale.


Indeed.
Title: Re: TV glass toxicity?
Post by: FlashGP on February 11, 2019, 08:57:26 AM
Hi OP

Re Radium Girls,

TRUE, alpha particles were to blame.  But they were pointing their paint brushes on their lips.  As a result they ingested a fair amount of radium.

The dosage and where it is applied is the key.  Swallowing large amouts of alphs emitters will eat you from the inside, as well as poison you.

Leave same in contact with your skin, and you get burns there, as you would if you sunbaked a spot way too long. 

In both instances there's also the increased risk of cancer. 

But there is a background level of alpha particles floating around that we take for granted.

I'm not advocating we eat the dust,  but basic hygene measures, including cleaning your machine should be sufficient protection for the small amount we would be likely to cut.

Regards
Gordon
Title: Re: TV glass toxicity?
Post by: Buch Metter on March 08, 2019, 05:56:32 PM
Grinding material is usually swept away with the water solution that  is dripped onto the lap.  I would be more concerned with where the drip bucket is poured and what is done with the resultant slurry, like, I wouldn't give it to the wife to use as a cosmetic masking agent on her face.
Title: Re: TV glass toxicity?
Post by: FlashGP on March 08, 2019, 07:52:45 PM
I wouldnt put it in the chook run or on the vegi gardes, no point in eating glow in the dark eggs and veg.

But the flower garden, mmmm fluoro flowers may look pretty.
Title: Re: TV glass toxicity?
Post by: roughcreations on June 20, 2019, 12:13:48 PM
Hi,
As an experiment, I recently took some hand-held XRF readings of tv-tube glass I collected from an old broken LG brand colour TV I found that had been dumped.

(http://www.roughcreations.com/wp-content/uploads/XRF_Unit.jpg)

The dark grey coloured sample is from the flat front section, and the other curved yellowish piece presumably from the side/back section.

Reading from curved yellowish piece of glass (below):
(http://www.roughcreations.com/wp-content/uploads/Back_curved_high_Pb.jpg)
Reading from flat dark grey piece (below):
(http://www.roughcreations.com/wp-content/uploads/Flat_Low_Pb-2-e1560996249553.jpg)

The lead (Pb) content varied markedly as you can see from the screen captures, below-detection in the flat piece, approximately 20% Pb in the curved piece. No other nasties such as cadmium in appreciable quantities, a sniff of arsenic in the high-Pb sample.
Summary:
(http://www.roughcreations.com/wp-content/uploads/Samples.jpg)
I was quite surprised by the variation in lead content, but the results back up some earlier comments.
Title: Re: TV glass toxicity?
Post by: Rusted on June 20, 2019, 06:03:11 PM
Someone has done the experiment. Excellent.
Thanks for that.
Title: Re: TV glass toxicity?
Post by: MakkyBrown on June 24, 2019, 09:30:32 PM
Welcome to the forum Rough Creations, good to see another Tassie member. I have not forgotten about sending you an email and I still have your card in my phone :)  I've been busy over the last few weeks, finished my designs book,webpage almost, robots all this week then national comp. Mid July and I should have some free time to help with an encoder on your machine if you want. I'll send you an email now I've got your card out. :)

RE: the TV glass, the grey glass is imo horrible and if anyone wants some I have a heap. Thought it was a good idea(smashing the old tv) for test cutting. But really topaz or cz, stones that actually look nice for your effort is a far better option.

CheersAndrew

Hi,
As an experiment, I recently took some hand-held XRF readings of tv-tube glass I collected from an old broken LG brand colour TV I found that had been dumped.

(http://www.roughcreations.com/wp-content/uploads/XRF_Unit.jpg)

The dark grey coloured sample is from the flat front section, and the other curved yellowish piece presumably from the side/back section.

Reading from curved yellowish piece of glass (below):
(http://www.roughcreations.com/wp-content/uploads/Back_curved_high_Pb.jpg)
Reading from flat dark grey piece (below):
(http://www.roughcreations.com/wp-content/uploads/Flat_Low_Pb-2-e1560996249553.jpg)

The lead (Pb) content varied markedly as you can see from the screen captures, below-detection in the flat piece, approximately 20% Pb in the curved piece. No other nasties such as cadmium in appreciable quantities, a sniff of arsenic in the high-Pb sample.
Summary:
(http://www.roughcreations.com/wp-content/uploads/Samples.jpg)
I was quite surprised by the variation in lead content, but the results back up some earlier comments.
Title: Re: TV glass toxicity?
Post by: FlashGP on June 25, 2019, 07:59:31 AM
Hi Makky,  the high lead glass should be the front of the screen, to protect the viewer from X radiation.

TV screens have tens of thousands of volts potential in them, the little 16 inch screens we ran in space invader mavhines ran at between 15000 and 25000 volts.  The bigger the screen, the higher the voltage.

When breaking a svreen, first earth one end of the probe to the chassis, then poke the business end under the rubber flange over the end of the HT lead where it meets the screen.  If the screen is live, it will discharge with a crack.  It is then safe to handle.

Remove the yoke, a good source of copper binding wire, and break the neck of the tube off with a hammer.  It is thin here and the safest place.  You can then saw up the tube with lapidary equipment, or a diamond blade on an angle grinder if you take precautions to avoid breathing the dust.

RegardFlash.
Title: Re: TV glass toxicity?
Post by: roughcreations on June 25, 2019, 07:26:30 PM
Hi Makky,
Thanks for the welcome. I was on this forum lurking a few years ago, but my account got banned because I was sometimes behind a VPN, and the forum software doesn't like that, it automatically labelled me as a spammer, lol.
I am really interested in encoders after hearing from you about their application to faceting machines, and also now that I searched and found the relevant forum thread I understand the requirements a lot better.

I bought my trusty Facetron from the fine folks at Aussie Sapphire a few years back, the machine has an exposed moving pivot bolt on the side facing the user, the other end of the pivot bolt is covered with a block of alloy, housing the dial gauge etc. It seems like an encoder should be quite do-able, at least from first impressions and a thread for Facetron conversions might be quite a good resource given the number of owners of this brand on the forum. I am not in any great hurry, but it would be good to get an idea of the work involved for this make sometime in the next few months when time allows.

Yeah, the TV glass is a novelty I guess, but there's lots of other readily available gemstones out there that look even better when well cut (smoky quartz anyone?).

Cheers,
Laurie
(RoughCreations).
Title: Re: TV glass toxicity?
Post by: Ghost on June 25, 2019, 07:37:46 PM
I have a very nice piece of Toohey's Topaz that I cut from rough that was found on the roadside in Victor Harbor.
Title: Re: TV glass toxicity?
Post by: roughcreations on June 25, 2019, 08:11:59 PM
Shouldn't that be 'West End' topaz rather than Tooheys for S.A.? Spent a lot of time travelling the stretch of road between Goolwa and Victor in my earlier years.
I have this piece of Broad Arrow Pub amethyst I am pondering how to cut - it's actually the base of a beer glass..
(http://www.roughcreations.com/wp-content/uploads/broad_arrow_pub-e1561457628331.jpg)

Title: Re: TV glass toxicity?
Post by: MakkyBrown on June 25, 2019, 10:37:38 PM
Big low RI heart/trillion/pear. Three fold symmetry that is powerful at low RI. 
Like this, Gemray at RI 1.52 :) Chat in July about machine.CheersAndrew


(http://aussielapidaryforum.com/forum/gallery/9/medium_5704-250619223642.png) (http://aussielapidaryforum.com/forum/index.php?action=gallery;sa=view;id=9075)
Title: Re: TV glass toxicity?
Post by: Rusted on June 26, 2019, 09:33:50 AM
Broad arrow pub, that was an interesting place back in the day.

Could your purple beer glass actually be a part of a telegraph pole insulator?
Title: Re: TV glass toxicity?
Post by: roughcreations on June 26, 2019, 11:56:26 AM
Yes an interesting part of the world. I used to work in a gold mine south of Kalgoorlie back in the late eighties, however I didn't actually collect this piece myself - I was given it at lapidary club - it has some diamond saw cuts. I will ask the person who gave it to me what shape it was initially when I see them next. Here is another view:

(http://www.roughcreations.com/wp-content/uploads/broad_arrow_pub2.jpg)
Title: Re: TV glass toxicity?
Post by: MakkyBrown on July 17, 2019, 10:22:29 PM
Hey RCreations,I've just got sitting beside me a nice chuck of smashed glass bottle base with a very nice colour to it. Very similar colour to your piece, so next on the dop will be it. I'll practice what I preach so to speak and cut a nice big trillion from it.I'll also try and drop into the club Tuesday.
CheersAndrew
Title: Re: TV glass toxicity?
Post by: MakkyBrown on July 17, 2019, 11:08:51 PM
My bit of glass :)
(http://aussielapidaryforum.com/forum/gallery/9/medium_5704-170719230719.jpeg) (http://aussielapidaryforum.com/forum/index.php?action=gallery;sa=view;id=9079)
Title: Re: TV glass toxicity?
Post by: MakkyBrown on July 19, 2019, 08:53:54 PM
Turned out really nice. I tried to take a good photo but failed, not having much luck with good photos. So I just took this with flash. It is slightly darker than the gem but not a bad representation of what it's like.(http://aussielapidaryforum.com/forum/gallery/9/medium_5704-190719205128.jpeg) (http://aussielapidaryforum.com/forum/index.php?action=gallery;sa=view;id=9080)
Title: Re: TV glass toxicity?
Post by: roughcreations on July 20, 2019, 04:46:07 PM
Wow, with a capital W!
I have been interstate for the school holidays with the family, missed lapidary club for the last few weeks and arrived back home today - just saw your post.
The photo looks amazingly good to me, but agree, faceted gems are the hardest things to photograph. Would love to see the stone in person some time!
Title: Re: TV glass toxicity?
Post by: roughcreations on July 20, 2019, 04:52:26 PM
Hi Makky,
Once again, I can't believe it's not a concave-cut with that scintillating performance. What sort of size and/or carat is it?