Re: [CAD_CAM_EDM_DRO] Re: Any "Best Practice" Recommendations for clearing chips and feed/speed when

Hi All:
There was a note in a recent issue of "Model Engineers Workshop" where a
fellow described sustaining serious burns from combustion of aluminum and
steel grinding residue.
He apparently was grinding steel on an abrasive belt machine that had
previously been used to grind aluminum rivets to length, and was blasted
with a substantial fireball when the mixture ignited.
I guess the sparks from the steel were sufficient to set the mixture off.
I have frequently had the grinding residue from my surface grinder begin to
smoulder inside the guard. Very stinky!!
Cheers

Marcus

----- Original Message -----
From: "capteod" <mfgguru@...>
To: <CAD_CAM_EDM_DRO@yahoogroups.com>
Sent: Sunday, December 23, 2001 12:01 PM
Subject: [CAD_CAM_EDM_DRO] Re: Any "Best Practice" Recommendations for
clearing chips and feed/speed when


> In your recent post I noted your claim that THERMITE was known for
> self ignition. This is WRONG. Thermite requires a ignition source
> in excess of 1400 degrees. When it starts burning it will generate
> temperatures of 6700 degrees F.
>
> The problem many people in the metal working industry have had is
> grinding swarf which contains both aluninum oxide and steel or
> ferrous oxides, that thas dried and were ignited by heat generated
> when maching without coolant.
>
> This is a major problem. We were aerospace parts manufacturers and
> have a lot of experience in this area. We have experimented to
> ignite thermite in our scrap area and we needed either an oxy-
> acetelyne torch, burning magnisium or an arc welding bachine. The
> military uses an ignition train of magnesium oxide mixed with a
> nitrocellulose binder in its THERMITE grenades. These are used for
> the destruction of metal parts in the case you want to destroy items.