[TheForge] Working copper

[Dave Brown]

At 14:55 03/12/02 -0500, you wrote:
>Many thanks for the advice on edge joining copper...very much appreciated.
>
>But a question, Dave, and probably a dumb one. What do you mean by 'tinning
>the tabs first'? Do you mean just fluxing and putting solder on them

Yep.  In spite of the fact that you're using solder, it's still called 
tinning just like it is when you clean a soldering iron (actually copper) 
and put fresh solder on the working surfaces so they stay clean longer when 
being heated.

>I do have some pure tin if necessary. I'm kinda
>guessing that is just an expression for soldering

Yep, you're right.  You ain't near a dumb as I look, is you?  It's just 
putting a very thin layer of solder on at least one of the surfaces to be 
mated.  You don't have to worry about good capillary action to get the 
solder all the way into the joint, it's already there.  It doesn't take a 
lot of solder to make a good lap joint, just so that there is solder 
covering the whole of the mating surfaces.

>Also another question, if I may: If successfully soldered, should I be able
>to cold work them flat just as if it was the copper sheet, without them
>coming apart?

I think, and I'm not really sure here, but that if the fit is tight then 
there will be very little solder inside the joints and you should be able 
to work it a little.  But the Solder is harder than the copper, so working 
the copper will be tough.  Also, once soldered you will not be able to 
anneal the work area again.  I think the solder will get brittle when the 
area is worked and the joining might weaken.  But this can be solved with a 
little judicious and delicate torch work.  Again, I'm not positive 
here.  There's as much guessing as there is experience and book-learning in 
this last bit.

Dave
<who should stay out in the shop instead of constantly coming in and 
checking e-mails>