Hi Jerry

I'd never heard of that issue -- it sounds very plausible. ???In any case, using stones on any soft metal is not recommended because it loads up the stone, making grinding much more difficult. ???That in itself -- making a task more difficult than it should be -- is a paramount safety concern. ???Easier work is always safer work.

Almost without exception*, you should use a carbide burr or fiber cut-off wheel for grinding/machining soft metals, except for finish work with sandpaper (e.g., cartridge rolls). ???I admit that I frequently disregard this myself on small jobs, and use a stone or whatever's chucked up in the die grinder or Dremel at the time.

*If you have a mill, lathe, or CNC machine, use the appropriate HSS or carbide tooling.

I'm not sure how to handle machine-cutting magnesium, since it frequently isn't marked as same, and if you strike a spark on it, you may get fireworks. ???Cooling/lubricating fluid is always a consideration for metal-cutting, though not always a requirement.

73
Jim N6OTQ

PS -- Mixed aluminum cuttings and steel or iron cuttings -- makes thermite.

________________________________
From: jerry massengale <j_massengale@...>
To: TekScopes@...
Sent: Tuesday, February 26, 2013 9:12 AM
Subject: Re: [TekScopes] OT: WD40 depressing experience


Hi,

Another warning about grindstones, never use them with soft metals like aluminum or brass or copper. Bits of the metal can become imbedded in the porous stone and then expand when heated and shatter the stone. My uncle was almost killed when his grindstone shattered and a chunk did damage to his foredead. The stone has bits of brass inbedded in it.




Jerry Massengale

?

Getting off topic, but more than one lathe has been lost to a magnesium fire.

Once it starts, you're in real trouble and you pretty much have to let itself
burn out. God help you if the chip tray was full. You can't dump water on it.

I can think of worse things to machine, but that's up there.

Paul

On Tue, Feb 26, 2013 at 07:30:47AM -0800, Jim wrote:
> Hi Jerry
>
> I'd never heard of that issue -- it sounds very plausible. ?In any case, using stones on any soft metal is not recommended because it loads up the stone, making grinding much more difficult. ?That in itself -- making a task more difficult than it should be -- is a paramount safety concern. ?Easier work is always safer work.
>
> Almost without exception*, you should use a carbide burr or fiber cut-off wheel for grinding/machining soft metals, except for finish work with sandpaper (e.g., cartridge rolls). ?I admit that I frequently disregard this myself on small jobs, and use a stone or whatever's chucked up in the die grinder or Dremel at the time.
>
> *If you have a mill, lathe, or CNC machine, use the appropriate HSS or carbide tooling.
>
> I'm not sure how to handle machine-cutting magnesium, since it frequently isn't marked as same, and if you strike a spark on it, you may get fireworks. ?Cooling/lubricating fluid is always a consideration for metal-cutting, though not always a requirement.
>
> 73
> Jim N6OTQ
>
> PS -- Mixed aluminum cuttings and steel or iron cuttings -- makes thermite.
>
>
>
> >________________________________
> > From: jerry massengale j_massengale@...>
> >To: TekScopes@...
> >Sent: Tuesday, February 26, 2013 9:12 AM
> >Subject: Re: [TekScopes] OT: WD40 depressing experience
> >
> >
> >Hi,
> >
> >Another warning about grindstones, never use them with soft metals like aluminum or brass or copper. Bits of the metal can become imbedded in the porous stone and then expand when heated and shatter the stone. My uncle was almost killed when his grindstone shattered and a chunk did damage to his foredead. The stone has bits of brass inbedded in it.
> >
> >
> >
> >
> >Jerry Massengale
--
Paul Amaranth, GCIH | Rochester MI, USA
Aurora Group, Inc. | Security, Systems & Software
paul@... | Unix & Windows

?

The point is -- we AREN'T enforcing our existing laws, rules, and regulations -- because we already have way too many of them. ?And "we" applies to every first-world nation on the planet and most of the second-world nations too. ?Since third-world places like Mali have no law except the law of the jungle and the force of arms, they don't count.

About the time of the Magna Carta, most of the rest of us figured out how to avoid that.

73

Jim N6OTQ

---

From: "tubesnthings@..."
To: TekScopes@...
Sent: Monday, February 2 5, 2013 9:19 PM
Subject: Re: [TekScopes] OT: WD40 depressing experience

Yes, Jim, agreed.

But, who wants an army of "federales" breathing down their necks (and other parts),?like so much?"hopeless in-security"... Look at FAA, which is chartered to, both promote AND regulate aviation! Talk about an impossible, self-contradictory mandate. They've done much towards?killing general aviation and are spending vast sums doing?it. Enforcement must be the last resort.

?

Imagine a population that is?bright enough to understand and?appreciate the intent of law, and insist on rules that are worthy of?the true respect of the citizenry...?

?

Then we might actually enjoy what we're supposed to be about - sigh

B

?

?

In a message dated 2/25/2013 6:49:04 P.M. Pacific Standard Time, n6otq@... writes:

?

Bernd,

It looks like you left a sentence off of that well-deserved and well-intended diatribe:

? ? "Obey and enforce all existing laws, rules, and regulations FIRST."

Without that, there's less than zero point in instituting new?laws, rules, or regulations.

This applies to all sectors of American law and regulation.

73

Jim N6OTQ