[Otto Nobedder]

This is a continuation of an interesting discussion under the topic "project stardust", that was going off-topic.

kermdog, I figure I've breathed enough hexavalent chromium from stick and flux-core welding of stainless, that the damage is probably already done. Since heat affects stainless, making 304 (the alloy I most encounter) somewhat magnetic, the magnet-in-the-hood idea might give one an idea just how much exposure happens. As I still occasionally MIG with 308 & 309, I might have to try this myself.

Your idea of examining the spread of metal dust from a job site is very interesting. Microscopic particles of iron/steel, could conceivably travel long distances on the wind. Remember the volcanic ash from Mt. St. Helens? We had a good 1/4" accumulation at my family's farm in southern MO!

Steve

[Otto Nobedder]

My apologies.

ProjectStardust was the author; "Welding, cutting torch, and meteorites!" was the topic.

Steve

[Otto Nobedder]

kermdawg,

I just remembered you'd said you were 16 years younger than me, so Mt. St. Helens would have been before you were born. The ash cloud was launched high in the atmosphere, and carried across North America an into the Atlantic. Ash was detected in Europe.

I'm not suggesting steel dust travels that far, but if you're welding and/or grinding at 130' above ground on a breezy day, it could potentially travel a mile or more. (I arrived at that figure by the WAG method, by the way .)

Steve

[kermdawg]

Whats the wag method?

I just asked my wife whos 5 years older than me if she was alive when St. Helens erupted. Amonth and a day before she was born lol :p Shes from up in washington, by seattle.

Anyway, what Im really curious about would be the actual WEIGHT of the particles, the differances in weight in particles from grinding differant types of material with differant types of blades/stones/equipment, and how far they would travel/carry depending on air current, speed and updrafts. Remember alot of us weld with little fans next to us to. And especially out here in the summer time when its 110 ambient alot of the other trades got fans goin to(mainly the elevator operators, those bastards got it MADE)

Heres the thing about this and everything other airborne particle-even if it does manage to spread 100 or 1000 miles, or like the radiation from Japan hittin our soil here in Nevada, well over 10,000 miles away, it begs the question-What the hell could we possibly do about it to keep it contained? No matter what you do your not going to get all of it. Thats the reason for the government "safe limits" and so forth (which is a load of crap if you ask me).

But the original topic is at still interesting to me.

[Otto Nobedder]

WAG= "Wild-ass guess"

The heavier the particle, the shorter the travel distance. (Presumably.)

That is why I'm interested in the experiment you've suggested. It's not really complicated to perform.

But, as you said, if the results are unhealthy, what can we do? We can't practically set up magnetic containment around a jobsite.

Steve

[kermdawg]

Think of the shape of the particle-a heavier particle shaped like a golf ball will go much farther than a lighter particle of a differant shape

I like the Wag method :p

[Otto Nobedder]

Think of the shape of the particle-a heavier particle shaped like a golf ball will go much farther than a lighter particle of a differant shape...

IF you're referring to a golf ball, launched at a significant velocity relative to free air.

Texture will not really affect the "loft" of a particle moving WITH the air. Or will it? I'm glad I'm not alone in being interested in these questions.

Steve

[Otto Nobedder]

[quote="kermdawg"...I like the Wag method :p[/quote]


The WAG method is the heart of TLAR engineering. When you find yourself fitting and welding in an "as built" situation, you must rely on WAGs until you achieve TLAR standards. (TLAR= That looks about right.)

Steve

P.S. I dare you to use these terms on a resume'

[kermdawg]

Im thinking of the aro qualities of it ala the mythbusters episode where they golfballed a car and got vastly improved gas mileage.

[Otto Nobedder]

Im thinking of the aro qualities of it ala the mythbusters episode where they golfballed a car and got vastly improved gas mileage.

These particles are being moved by the wind, though. They are not "forcing" their way through it, like a car or a golf ball.

In retrospect, if the dimpling reduces air resistance (which has been proven), particles with such dimples should be carried SHORTER distances, as the wind shouldn't hold them aloft as long.

Steve

[kermdawg]

Well the way I look at it (which is probably completely wrong) one of newtons laws of motion states that for every action there is a reaction-therefore, an object cant move through the air without a force causing it to do so, and that force imparts energy to the particle, moving it through the air.

I get what your sayin though. But that particle is being forced through the air somehow. Im kinda thinkin like a glider, ya know it can swoop down and up and travel many times over something on a linear path could by riding wind and air currents. Thats where the dippling would aid it, reducing drag and increasing its overall distance.

Like I said, I could be completely wrong on that though :p

[Otto Nobedder]

Think more like a balloon. Nothing is pushing it through the air. It's moving because the air around it is moving.

A chunk of weld spatter, a piece of grinder grit, a shaving from your file, loses the energy it was "launched" with in a few feet of travel, due to friction. Your dimpled particle will travel a foot or two farther before the energy is lost. At that point, it is at the mercy of the winds. I've seen grinding sparks travel 30 ft, then fall to the ground. You've got me interested in the TINY particles we never see flying, that the wind could keep aloft indefinitely like a Wal-Mart bag floating over the interstate.

Steve

[TheExpert]

Stardust beginning in the 1980s, scientists began seeking a dedicated mission to study a comet.

[lanceman73]

Black boogers=good day of welding!