Lead weights ...

"Patch" wrote

>I am curious if the Sea Pearls plain (uncoated) weights will mark up our
> BCD's. We use coated weights now, but since the plain, uncoated ones are
> cheaper, I would like to try them. We have Zeagle's, and have the little
> yellow pouches, but it is simpler to just stuff the weights into the
> weight
> pockets, and remove when packing up.

> The soft weights are an option also, and I assume they are cleaner because
> of the bag.

Uncoated lead and salt water are not an environmentally friendly
combination. That doesn't stop dive operators from all over the world from
using them, but those that are sensitive to such issues don't. Soft weights
contain coated shot and, while usually more expensive than coated or
uncoated hard weights, are a lot more comfortable.

In answer to your question, no, uncoated weights will not mark up your BCD.

Lee

"Lee Bell" <leebell@ix.netcom.com> wrote in message
news:xXpIe.2984$ns.2540@newsread1.news.atl.earthli nk.net...
>
> Soft weights contain coated shot and, while usually more expensive than
> coated or uncoated hard weights, are a lot more comfortable.
>

I would be suspicious of any claim that shot-filled weights were either
coated or environmentally friendly. While some shot might be coated, I have
not seen any that are. I have seen many that had the shot enclosed in a
plastic bag of some kind. Coating the individual shot would be expensive.
Most of these are then enclosed in a fabric bag. Scubapro uses a double
vinyl bag.

The problem with shot is that as it is used the shot rub against one another
and produce lead dust. The process is about the same as tumbling the inside
of your tank or polishing rocks in a tumbler. Even if the shot were
coated, the coating would eventually wear away. If the shot is enclosed in
only a mesh bag, the dust leaks out into the environment. When you get home
from a dive and drop your weights on the mudroom floor it flows out with
watever water is left and leaves a little grey puddle of lead dust.

You might think the problem is solved by sealing the shot in a plastic bag.
The fact is that the dust is still formed by the grinding of the lead shot
and eventually the bag will always rupture. I once tossed a Scubapro weight
on the sole of my boat after a cold November dive. The vinyl package was
brittle and broke open. I am still finding little pieces of lead shot in
the carpet of my boat, five years later.

Coated solid weights work well in isolating the lead but many divers believe
that they are too uncomfortable. Uncoated lead may actually be almost as
good because the lead, just like aluminum, quickly forms an oxide coating
which prevents further corrosion and leaching out of the lead.

I'm not a chemist. Maybe one might want to add to this discussion...

Safe diving,
Cpt. Dale

Good point ... had not thought of the saltwater/enviornment thing. I wonder
how the the shot in the soft weights is different than the solid, web thru
weights, althought they do say coated shot.

I tried to paint (dip) the uncoated weights that I had ... don't go there
anyone.

I think I will just go with the solid, coated weights. They sell them at
the local dive shop.

Thanks ...

John

"Lee Bell" <leebell@ix.netcom.com> wrote in message
news:xXpIe.2984$ns.2540@newsread1.news.atl.earthli nk.net...
> "Patch" wrote
>
> >I am curious if the Sea Pearls plain (uncoated) weights will mark up our
> > BCD's. We use coated weights now, but since the plain, uncoated ones
are
> > cheaper, I would like to try them. We have Zeagle's, and have the
little
> > yellow pouches, but it is simpler to just stuff the weights into the
> > weight
> > pockets, and remove when packing up.
>
> > The soft weights are an option also, and I assume they are cleaner
because
> > of the bag.
>
> Uncoated lead and salt water are not an environmentally friendly
> combination. That doesn't stop dive operators from all over the world
from
> using them, but those that are sensitive to such issues don't. Soft
weights
> contain coated shot and, while usually more expensive than coated or
> uncoated hard weights, are a lot more comfortable.
>
> In answer to your question, no, uncoated weights will not mark up your
BCD.
>
> Lee
>
>

Cpt Dale writes:
> I'm not a chemist. Maybe one might want to add to this discussion...

Overall, while its always a good idea to eliminate pollution sources,
the contribution of this one is masked by background noise, namely the
lead that already occurs in seawater.

It is estimated that the Earth contains around 326 million cubic miles
of water, of which roughly 300 is seawater, as per:
http://www.celestopea.com/OTEC.htm

A detailed composition of seawater can be found here:
http://www.seafriends.org.nz/oceano/seawater.htm

....which states that Lead is present at around 0.00003 ppm.

What this means is that (300 million) * 0.00003 (parts/million) = 9,000
cubic miles of lead are currently in the oceans.

To convert this to a mass, lead is around 8.5g/cc, so the amount of
lead already in the oceans is:

= [(8.5 gram)/ (1 cm^3)] * (9000)
(miles^3)*(5280ft/mi)^3*(12inch/ft)^3*(2.54cm/inch)^3*(1lb/454gram)*(1
ton/2000lbs)

= (8.5)*(9000)*(147,197,952,000)*(1728)*(16.387064)* (1/454)*(1/2000)

= 351,173,909,301,987 tons

= ~350 trillion tons


Assuming that every diver in the world were to lose a quarter pound per
year, at 2 million active divers, that's a half million lbs/year, or
250 tons/year.

This sounds like a lot until you divide to get the Signal:Noise ratio:
it then works out to roughly a "1 to quadrillion" ratio.

What this would work out to is that for a 1 part per billion change, it
would require 1 million years of diving (eg, 1B * 1M = 1Q).

Pragmatically, if we look for the significant manmade sources of lead
pollution of our oceans, we find that most are due to lead being an
airborne combustion byproduct that then comes out due to rainfall. I
believe that the big contributors are considered to be from vehicle
emissions (in particular from back when we used tetraethyl lead in
gasoline, at around a 1%-2% concentration). Coal for electrical
generation is also a known contributor, but the EPA estimated that they
released only 3,283 tons of lead compounds into the environment in
1999, which was <2% of all lead released by industries (which summed to
188,686 tons of lead and lead compounds into the environment in 1999),
and worldwide, the total sum would obviously be higher.

Using this last datapoint and our previously listed assumptions,
divers' weightbelts would notionally be responsible for no more than
~0.1% of all lead pollution.


-hh

Cpt. Dale Bennett wrote:
>

> The problem with shot is that as it is used the shot rub against one another
> and produce lead dust. The process is about the same as tumbling the inside
> of your tank or polishing rocks in a tumbler. Even if the shot were
> coated, the coating would eventually wear away. If the shot is enclosed in
> only a mesh bag, the dust leaks out into the environment. When you get home
> from a dive and drop your weights on the mudroom floor it flows out with
> watever water is left and leaves a little grey puddle of lead dust.
>

Yep, and if it tracks into the house or you don't clean your hands
before eating (remember to wipe off the faucet handles afterwards too),
you can expose yourself or your family and your pets to lead poisoning.
Lead gets stored in your brain, organs, and bones after leaving your
bloodstream - so even getting a blood level won't tell you your lifetime
exposure to the stuff.

If you do notice lead dust from soft weights, don't try to vacuum it -
you will just throw it into the air where you can breathe it into your
lungs. Sweeping dry can do the same. You should mop it up with a wet
rag and bag it for disposal. Be especially careful if kids are in the
house.

-hh wrote:

> Pragmatically, if we look for the significant manmade sources of lead
> pollution of our oceans, we find that most are due to lead being an
> airborne combustion byproduct that then comes out due to rainfall. I
> believe that the big contributors are considered to be from vehicle
> emissions (in particular from back when we used tetraethyl lead in
> gasoline, at around a 1%-2% concentration). Coal for electrical
> generation is also a known contributor, but the EPA estimated that they
> released only 3,283 tons of lead compounds into the environment in
> 1999, which was <2% of all lead released by industries (which summed to
> 188,686 tons of lead and lead compounds into the environment in 1999),
> and worldwide, the total sum would obviously be higher.
>
> Using this last datapoint and our previously listed assumptions,
> divers' weightbelts would notionally be responsible for no more than
> ~0.1% of all lead pollution.
>
>
> -hh

Don't forget all the stuff with lead solder in the landfills
contaminating ground water - electronics, autos, etc. We do way more
damage to the environment being consumers than we do diving. There is a
move for industry to go to lead free solder - but I've tried several
kinds of the stuff and there are various issues with that as well.

"Cpt. Dale Bennett" wrote

>> Soft weights contain coated shot and, while usually more expensive than
>> coated or uncoated hard weights, are a lot more comfortable.

> I would be suspicious of any claim that shot-filled weights were either
> coated or environmentally friendly. While some shot might be coated, I
> have not seen any that are. I have seen many that had the shot enclosed
> in a plastic bag of some kind. Coating the individual shot would be
> expensive. Most of these are then enclosed in a fabric bag. Scubapro uses
> a double vinyl bag.

I can't swear that all led shot is coated, only that some of it is. I'm
quite sure that some of my weights specifically mentioned that the shot was
coated.

> The problem with shot is that as it is used the shot rub against one
> another and produce lead dust. The process is about the same as tumbling
> the inside of your tank or polishing rocks in a tumbler. Even if the
> shot were coated, the coating would eventually wear away.

Correct. That's why articles discussing the issue have always said that,
when you notice grey water coming from your shot pouches, it's time to
replace them.

> If the shot is enclosed in only a mesh bag, the dust leaks out into the
> environment. When you get home from a dive and drop your weights on the
> mudroom floor it flows out with watever water is left and leaves a little
> grey puddle of lead dust.

It's time to replace them.

Lee

In article <3lf65vF127q7aU1@individual.net>, greatviz
<invalid@invalid.invalid> wrote:

€ -hh wrote:
€
€ > Pragmatically, if we look for the significant manmade sources of lead
€ > pollution of our oceans, we find that most are due to lead being an
€ > airborne combustion byproduct that then comes out due to rainfall. I
€ > believe that the big contributors are considered to be from vehicle
€ > emissions (in particular from back when we used tetraethyl lead in
€ > gasoline, at around a 1%-2% concentration). Coal for electrical
€ > generation is also a known contributor, but the EPA estimated that they
€ > released only 3,283 tons of lead compounds into the environment in
€ > 1999, which was <2% of all lead released by industries (which summed to
€ > 188,686 tons of lead and lead compounds into the environment in 1999),
€ > and worldwide, the total sum would obviously be higher.
€ >
€ > Using this last datapoint and our previously listed assumptions,
€ > divers' weightbelts would notionally be responsible for no more than
€ > ~0.1% of all lead pollution.
€ >
€ >
€ > -hh
€
€ Don't forget all the stuff with lead solder in the landfills
€ contaminating ground water - electronics, autos, etc. We do way more
€ damage to the environment being consumers than we do diving. There is a
€ move for industry to go to lead free solder - but I've tried several
€ kinds of the stuff and there are various issues with that as well.
€
€

It's more than a movement, it's law:

http://www.pb-free.info/laymans_terms.htm

"Alan Street" <agstreet@nonono_san.rr.com> wrote in message
news:040820051222474333%agstreet@nonono_san.rr.com ...
> In article <3lf65vF127q7aU1@individual.net>, greatviz
> <invalid@invalid.invalid> wrote:
>
> ? Don't forget all the stuff with lead solder in the landfills
> ? contaminating ground water - electronics, autos, etc. We do way more
> ? damage to the environment being consumers than we do diving. There is a
> ? move for industry to go to lead free solder - but I've tried several
> ? kinds of the stuff and there are various issues with that as well.
> ?
> It's more than a movement, it's law:
>

I could be wrong, but I don't think they have taken the lead out of solder
used in electronics yet. The high melting point needed for the substitutes
would be problematic for the many heat-sensitive components. Most of the
pressure to remove or reduce lead in solder was aimed at the solder used to
join copper pipes in drinking water supplies. It is always seen as more
important to us to avoid poisening ourselves than the critters around us.

Safe diving,
Cpt. Dale

In article <keWdnZ2dnZ1kzwuynZ2dnV3pb9-dnZ2dRVn-052dnZ0@comcast.com>,
Cpt. Dale Bennett <captndale@comcast.net> wrote:

€
€
€ "Alan Street" <agstreet@nonono_san.rr.com> wrote in message
€ news:040820051222474333%agstreet@nonono_san.rr.com ...
€ > In article <3lf65vF127q7aU1@individual.net>, greatviz
€ > <invalid@invalid.invalid> wrote:
€ >
€ > ? Don't forget all the stuff with lead solder in the landfills
€ > ? contaminating ground water - electronics, autos, etc. We do way more
€ > ? damage to the environment being consumers than we do diving. There is a
€ > ? move for industry to go to lead free solder - but I've tried several
€ > ? kinds of the stuff and there are various issues with that as well.
€ > ?
€ > It's more than a movement, it's law:
€ >
€
€ I could be wrong, but I don't think they have taken the lead out of solder
€ used in electronics yet.

You are. Anyone planning to sell consumer electronics into the EU in
2006 has to be in compliance with RoHS, which means lead free solders
(among other things). Every major semiconductor manufacturer on the
planet has spent a considerable amount of time and money getting ready
for this, and Pb-free solders are pretty much mainstream now for all
consumer electronics.



The high melting point needed for the substitutes
€ would be problematic for the many heat-sensitive components. Most of the
€ pressure to remove or reduce lead in solder was aimed at the solder used to
€ join copper pipes in drinking water supplies. It is always seen as more
€ important to us to avoid poisening ourselves than the critters around us.
€
€ Safe diving,
€ Cpt. Dale
€
€
€