Lead alloy

[High_Abbe]

I am interested in knowing the exact combination of metals and other things in the lead alloy used in the surfacing process. Anybody know?

[AWTECH]

117 alloy used for blocking is a Eutectic Fusible Alloy and its primary component is Bismuth. (The price has gone up, up, up over the past 18 months)

Fusible Alloys include a group of binary, ternary, quaternary, and quinary alloys containing Bismuth, lead, tin, cadmium and indium. The term fusible alloy refers to any of the more than 100 white-metal alloys that melt at relatively low temperatures.

Bismuth 44.7%
Lead 22.6%
Tin 8.3%
Cadmium 5.3%
Indium 19.1%

[Jim G]

Yeah but the lead and cadmium apparently dissolve in reclaim tanks and become the primary source for polution. The other metals are not of concern re: hazardout waste.

[AWTECH]

Yeah but the lead and cadmium apparently dissolve in reclaim tanks and become the primary source for polution. The other metals are not of concern re: hazardout waste.

Please explain do you think the alloy is excessively dangerous? If so why?

[Aarlan]

I would think the dangers would be self evident. the Dark cloudy reclaim tank water must be chock full of wonderful substances...cadmium and lead mainly of importance...Not that they can't be disposed of properly, but with all of the years surface labs dumped it down into our sewers...It simply can't be terribly good.


AA

[Jim G]

Re: AWTECH's q: "Please explain do you think the alloy is excessively dangerous? If so why?"

117 alloy is not "excessively dangerous" but requires careful handling such as wearing rubber gloves when blocking, not eating or smoking while blocking and caution with the waste water as both lead and cadmium leach out of the alloy into the water. (Don't drink it!)

I don't want to be quoted on this nor suggest that this is accurate but we tested the waste water in thhe reclaim tank and my recollection was that it approached the limit for being classified as a hazardous waste after about 150 pair of lenses (or 300 blocks). (Why do you think so many of we old lab rats are wacky?)

Here's a couple sites noting the MSDA for cadmium and lead.
http://www.veemetco.com/techdata/msds_cadmium.php
http://www.jtbaker.com/msds/englishhtml/l3391.htm

[AWTECH]

Do not drink from a reclaim tank. I guess that is a warning that needs to be posted on all reclaim tanks.

What about unflushed tolits, should all tolits have "Warning do not drink out of this."

What about those who change the oil in their own cars, they too need to be warned "Do not drink the used oil"

I don't know how many pennies one can swallow before it causes long term problems, so should the government now warn all of its citizens to not eat pennies. "Warning, swallowing pennies could cause medical problems in addition to increase weight." (and temporary loss of current assets, I am sure after death these can be removed and retain full face value)

At some point individual have to take resposibility for their actions.

[rsandr]

Do not drink from a reclaim tank. I guess that is a warning that needs to be posted on all reclaim tanks.

What about unflushed tolits, should all tolits have "Warning do not drink out of this."

What about those who change the oil in their own cars, they too need to be warned "Do not drink the used oil"

I don't know how many pennies one can swallow before it causes long term problems, so should the government now warn all of its citizens to not eat pennies. "Warning, swallowing pennies could cause medical problems in addition to increase weight." (and temporary loss of current assets, I am sure after death these can be removed and retain full face value)

At some point individual have to take resposibility for their actions.

I wouldn't drink from a toilet flushed or otherwise.

I agree with what you say but they who supply our alloy tell us it is safe. There has been no mention of rubber gloves, handwashing is done purely from common sense.

I intend to switch over to wax eventually, its just lensmaking, it really isnt worth the risk of handling mildly dangerous metals for years.