[TheForge] cutting propane cylinders- fuel-air mixture

[Ralph Sproul]

Bob, I think it depends greatly on how good your towel  and your scale
are.......

A metal surface is not perfectly smooth and things dry/adhere/stick to it.
When you take a piece of tank that has been cut apart (like a 275 gallon
drum - which I'd cut with an air chisel, as it'd take to dam much C02 to
approach it with a torch)........ then you heat the metal with a torch - the
first thing that comes is condensation........but then you'll notice the
blue/yellow streaming colors (on that water from condensation). As the water
vapors off and you have the smoke which is the fuel mixing with
air.........this is what will kill you if you do the torch thing.  The fuel
smoke mixes with the air, the metal heats up, the container goes off (that's
in the preheat stage).   If you really go for it and test the tank by laying
into the oxygen stream of a cutting torch - you severely speed up the
process of fuel air ratios with the oxidizer.

If you see an open section of tank skin some time - try it.  Oil/fuel that
is.  I'm not sure about propane (which is the topic header) - as I've never
torched one of those - or cut one open or used it for a forge.........I use
pipe instead.   That elliminates a lot of doubts.   :-)

Not that any tank is made of cast - but cast is extrememly
pourous.........and it's why the oil or pitch soaked castings are so
miserable to weld.  Steel is a far cry from that type of porous, but the
surface of the tank gets a coating of the fuel that dries on there.  This is
what keeps the inside of tanks from rusting for so long.

I did see some metal pictures from under a microscope in a metalurgy text
once.  It appeared there were "poures".........maybe fuel "sweating" off the
metal skin is a better way to put it............could you live with that?

Ralph

----- Original Message -----
From: "Schade" <schade at acegroup.cc>
To: "Sponsored by ABANA" <theforge at mailman.qth.net>; <munlaw2 at hcsmail.com>
Sent: Wednesday, March 30, 2005 5:07 PM
Subject: Re: [TheForge] cutting propane cylinders- fuel-air mixture


> Are there really "pores" in metal?
>
> If I take a "dry" piece of steel, let it sit submerged in a bucket of
> water overnight, take it out and dry it with a towel (always carry a
> towel) and weigh it (the steel), will it weigh more than before I
> "soaked" it? How much?
>
> Are some metals more porous than others?
>
> I have some doubts.
>
> Bob
> _______________
>
>
>
>
> On Mar 30, 2005, at 11:30 AM, Ron Childers wrote:
> >  the gasoline in the pores of the metal
> >
> > Ron C
> >
>
> On Mar 30, 2005, at 12:53 PM, Ralph Sproul wrote:
>
> >  sweat the fuel out of the pores of the metal.  This
>
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