[TheForge] Re: Artist-Blacksmith

[xlch58 at swbell.net]

Bill Roberts wrote:

> with all due respect, annealing isn't necessary........I have been  
> able to forge it well beyond what I thought I would without it work  
> hardening and splitting. Both aluminum and copper. My lil experiment  
> grew out of the desire to forge something and not fire up the forge  
> one HOT August.
> There are some examples on my site in the sculpture section. fwiw.
> bill
> Bruce will you be at the shindig? Andy mentioned that you  might 
> ........:)
> On Jun 12, 2006, at 9:08 AM, Bruce Freeman wrote:
>
The extent that you can get away with this all depends on the aluminum 
alloy you have chosen and the tempering and heat treatment it has 
already been subjected to.  For example, 6061 T6 , which is an aircraft 
grade material and is commonly found in scrap (it is very popular for 
extrusions), is pretty intolerant of cold work.  I am building a plane 
and use a lot of it, so am pretty used to it.  Annealing isn't an option 
for my usage, since getting the temper and its desirable properties back 
in the metal is difficult.    I believe magnesium added to the alloy is 
what enhances the materials work hardening characteristics.  Ordinary 
1100 series will take quite a bit of abuse before cracking, but it 
eventually will as well.  If all your doing is putting a simple series 
of gentle bends in the metal and not really reworking the same section 
over and over again, you are probably OK.  If what you are doing is 
making a saddle curve or making a wheel pant and altrnately shrinking 
and stretching the metal in the same area, then you will have to anneal 
it.   Tight bends will often crack even if the material is annealed.   
The same goes with copper.  Years ago, I had a plumber wokring on the 
house ( a truly rare occurance, but he was a sub to another contractor 
who oulled the overall permit)   Halfway through  the task at hand he 
announced that he would have to finish the next day as he needed a piece 
of soft line to finish and all he had was hardline left on the truck 
(soft line being the rolls of copper tube and hard line being the sticks 
of copper tube).  I got my torch and took his "hard line" played the 
torch over it long enough to get it hot enough and then quenched it and 
bent it freehand into the gentle sweep he needed.   He acted as if had 
never heard of such a thing before.  Personally, I think he just wanted 
to knock off early and at that point I wanted all of them done and out 
of my house for good.  

Charles