Grinding Leaded Glass

[jdm2008]

I need to grind about(.015-.030) a quarter inch from the bottom of a leaded glass sheet so it can fit into a sliding track to make the glass thinner. I was surprised when the I called the guy who does some other processing steps tell me he could not do this.
Is there some reason why this is a difficult undertaking? Obviously the glass does not have to be clear for the portion that is ground.

 

[Ceramicguy]

He probably declined due to the risk of lead exposure from the PbO in the glass. You might ask him if it was a technical issue or health and safety issue that prompted his response.

Bruce

http://www.accuratus.com

 

[berkshire]

You might also ask if the glass was tempered or plate.
Grinding on tempered glass tends to produce glass crumbs.
B.E.

The good engineer does not need to memorize every formula; he just needs to know where he can find them when he needs them. Old professor

 

[MiketheEngineer]

Yep - to both

 

[btrueblood]

Even if wet grinding (reducing dust exposure to the operator), waste disposal might be an issue too.

 

[swall]

I have to question the comments that lead in leaded glass is a health issue. Anybody got a sound basis for this?

 

[btrueblood]

Like all health issues, swall, it's arguable. And these days, it's pretty tough to argue the "don't worry about it" side with people educated by what the media tells them.

Lead oxide is a component of true lead glass, somewhere between 20 to 40%. Lead oxide is also the white pigment used in leaded paint, and you ought to know that anybody sanding on leaded paint surfaces these days must "suit up" and wear respirators, etc. Lead oxide is toxic, and will leach into acidic solutions in lead glass; wine stored in a leaded glass decanter reaches unsafe limits (well, relative to drinking water standards) in a day or less.

Lead is a cumulative poison in the human body, so avoiding exposure is fairly important. In my town, a lot of the schools have no drinking fountains right now, they are turned off because testing showed high lead levels (probably from the use of leaded brass in the plumbing/fixtures). Yes, the simple and smart answer is to let the faucet run for a few cupfuls before drinking, thus flushing the leachant-filled water down the drain...but we're talking public politics and that don't mix well with "smart".

Given the hassle over disposing of batteries, I'd guess there would be equivalent hassle over disposal of lead oxides, thus my comment regarding the swarf disposal.

There are non-lead versions of lead glass that give similar refractive index. It's where I'd look, if only to avoid the hassle.

More here:

http://en.wikipedia.org/wiki/Lead_glass

 

[chicopee]

Wouldn't grinding the edge of the tempered glass sheet craze the whole sheet instead of producing glass crumbs?

 

[jdm2008]

Thanks for the help everybody. I do not think the reason is a health issue since the same supplier also cuts the class with a milling machine.
I will have to get back with more details.

 

[swall]

Very informative, btrueblood.

 

[berkshire]

chicopee (Mechanical)
""" Wouldn't grinding the edge of the tempered glass sheet craze the whole sheet instead of producing glass crumbs?"""

Yes the whole sheet crazes and disintegrates into little pieces the size of breadcrumbs.
Thats what I meant when I said " Glass crumbs"

B.E.

The good engineer does not need to memorize every formula; he just needs to know where he can find them when he needs them. Old professor

 

[btrueblood]

"I will have to get back with more details."

Did you give your vendor a drawing showing what you wanted? Pictures, thousands of words, yada yada.