[TheForge] RE: Casting; to be or not to be...

[Michael]

We all have hopes and fears. The fact that it is the former from which the
latter grow is so well established as to be all but forgotten; that is
itself a stumbling block for everyone looking to accomplish their heart's
desire, because above all, fear blinds. The more we want a thing, the
greater the temptation to "throw the race," avoiding the risk of real
failure. With the addition of self deceit to protect our pride it is a
wonder that people ever accomplish anything.

 

Possibly aluminum is safer than bronze. It is also possible that a charcoal
furnace and a steel tube crucible are easier to build than a gas-fired
jeweler's furnace holding a clay-graphite crucible. That all sounds very
plausible; the shaded by-way often looks more inviting than the bustling
highway, but will it take us where we want to go?

 

Yes, aluminum casts at several hundred degrees less than bronze, yet liquid
aluminum will strip flesh from bones just as effectively; safety precautions
are needed for both. The only variable factor that applies to this
particular situation is pour size; the smaller the pour, the easier to
control; this is why so much time and effort has been devoted on
Castinghobby to building coffee-can furnaces by those of us with no
particular interest in them; to smooth the path for novices.  

 

A charcoal furnace is about two-thirds the work and expense of a well built
gas-fired furnace, because it doesn't need a lid. With a lid the gas furnace
is more pleasant, and healthier, to be around.

 

A properly built steel tube crucible is going to be more expensive than a
small clay graphite crucible, if your son's time is worth anything. The
risks involved will be about equal for a novice; the answer in either case
is to place a sheet metal firewall between the operator's legs and the mold.
If we plan for crucible failure it need be nothing more than a minor
aggravation (drain hole in furnace bottom; firewall; furnace and mold both
set over a sufficient amount of contained sand).

 

One thing is certain though, and that is he will get no joy from the effort
of casting aluminum when bronze parts are what he really wants to use. After
he has done all the work to build a charcoal furnace and finally gets to the
place where he can pour aluminum successfully, there will remain a different
mountain to climb. If he wished to make large pours, starting with aluminum
would be good advice, but in this case I would recommend the right way; not
the "easy" way.

Mikey

 


Subject: Re: Casting Newbie [Was: RE: [TheForge] Casting a power hammer?]