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Re: mercury

Many thanks for actually useful post. The many others are really VEILED 
advertisments. I asked many questions about fused quartz work and thought there
were a few people telling how competent they are no one helped!

Thanks again



> 
> > I think all of us are concerned, I go and have my blood checked periodically
> > for mercury. What can be done about blowing on hot leaded glass? Should we
> > all switch to another type of glass?
> 
> John & Howie,
> 
> I went thru a phase were I was absolutely panicked about mercury.  At a
> shop I worked at, I carried a charcoal trap that I put in line with my
> blowhose.  I refused to even seal a new bottle on the manifold without
> that trap. The bombing table there was like a toxic waste dump.  If you
> looked really close, there were minute droplets of Hg in EVERY crack and
> crevice.  The other benders called me "Mr. Paranoid."
> 
> I've relaxed a bit, as now I have my own shop and I treat mercury very 
> respectfully.  I did an extensive amount of personal research into Hg 
> contamination, and I have concluded the following:
> 
>     1.  Spills should be cleaned up immediately, before they disperse 
> into every smaller and smaller droplets.  A small suction device is good, 
> as is masking tape (yes, I got this out of Fusion magazine and it seems 
> to work great).
>     2.  The practice of sprinkling sulfur on Hg is only moderately 
> effective.  It does form a "skin" of HgS over the droplet, but does not 
> completely amalgamate it.  Finely powered zinc works better.  I have some 
> that is "60 mesh" size (whatever that is) and it reacts more vigorously 
> and completly than sulphur.  You can actually sweep these "rocks" up.  
> Some commercial Hg clean-up products contain sulphur mixed with strong 
> alkalines like lye.  This is supposed to be effective, but it's perhaps 
> only practical in a large-scale decontamination.
>     3.  Once you fail to take step #1, the decontamination process 
> becomes many fold more difficult - perhaps impossible without discarding 
> of contaminated surfaces.
> 
> I also believe a great way to control spills is to have your bombing table
> of a smooth surface, like Formica, and do all your filling on that table. 
> A shallow "ditch" routed around the perimeter of the table will catch any
> droplets that roll.
> 
> This all applies to spills of course.  The other sources of contamination 
> would be re-using mercury traps, exhaust from your mechanical pump, and 
> repairing mercury tubes.  All of these are avoidable.  The pump exhaust 
> can (should) exit to the outside.
> 
> I agree with Tom (he mentions in the SB article on him) that most people 
> use way too much Hg in tubes.  I have seen tubes with a giant pea-sized 
> glob rolling around.  All that's needed is enough to vaporize to an 
> equillibrium with the filling pressure of the tube.  This is usually just 
> a few "salt" grains.  It takes a bit longer to age in the tube, but once 
> it does it lights just as well even in cold weather.
> 
> I feel comfortable because I know I'm doing everything I can to protect 
> my health, and I know many older neon folks that were much more careless 
> during their carrers. Most of them are okay.  I know that's a lousy 
> gauge of effectiveness, but it makes me feel better! 
> 
> As to lead glass - I have wondered about that too, but I have never heard 
> evidence that any lead is volatilized during the heating process.
> 
>      -John Anderson
> 
> 
>
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