Re[2]: ATM - Casting Aluminum

[Dwight Elvey <elvey@hal.com>]

Dale Carlson <drc@oz.net> wrote:
> 
> I feel I should tell of my own stupidity, just
> as a caution.
> 
> I'd been making some small zinc castings, using US
> plated pennies for metal. Probably illegal, but
> they melt like butter with the direct heat from
> 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!
> 
> Dale

Hi
 It should be noted that the problem was heating
the cemment with a torch and not the aluminum.
Heating cemment turns it back into gypsum, giving
off water in the process. Steam is what caused the
explosion. Never heat regular cemment with a torch
or use it for a refractory surface in a furnace.
Dwight