Re: ATM - Casting Aluminum

["Paul Hettrick" <P.Hettrick@bom.gov.au>]

>a small butane torch :) After much success, I
>decided to see if a small piece of aluminum would
>melt in the same way. I cut about a half-inch
>piece off a scrap screen door frame (hard aluminum).
>I sat it on a concrete slab and began heating it with
>the torch. The resulting explosion blew a 1 inch deep
>crater in the concrete slab. Better that than me :)
>
>I trust that nobody on this list would try such a foolish
>experiment, but I just thought I'd mention it!


I dare say that this was due to the localised heating of the concrete with
the stresses induced by local expansion and possibly vaporisation of water
within the slab causing the explosion.  Or maybe that's what you were
implying anyway??

Just a note on an earlier message in this thread about using scrap aluminium
alloy wheels.  One would have to be sure they are only aluminium and not
magnesium-aluminium alloy.  Most Mg-Al alloys (although I'm not sure about
that used in wheels) are about 80-90% Mg and we all know that Mg burns
nicely in the presence of oxygen!

Paul Hettrick
Melbourne
Australia