I did some brazing a few weeks ago - been a long time - and long re-learning...
It was on copper sheet - 32oz and 64oz - 110 copper - 99.99999% IIRC.
It was a rough go - using lots of oxy on it.
It was copper to copper with bronze filler and a small torch.
What I found was - used some borax type flux that was around the filler -
but what did the trick - paint the area with electronic flux - then braze
on top of it. Get a nice puddle - and naturally alloy - then add the item
that needed to be added. This was while it was hot and fluxed. The white
flux around the filler worked to a lessor extent but worked only in protected
air space - no air flow.
Copper was a pain in the neck. I did the exact same thing with the sheet of steel
and the add on part still copper pipe. Beautiful flowing glob - and adding the
copper, it froze the top, but adding heat, it flowed around both nicely.
I think the real trick is this : Must get the brazing material to whet on the
surface and flow. Once it is on one then the other is the job.
Might be best to do two jobs and then heat them together.
Martin
Martin Eastburn
@ home at Lions' Lair with our computer lionslair at consolidated dot net
NRA LOH, NRA Life
NRA Second Amendment Task Force Charter Founder
Wayne Cook wrote:
On 21 Oct 2005 17:43:16 -0700, wrote:
I noticed that there are actually phosphor bronze electrodes for SMAW.
According to the datasheet (http://tinyurl.com/dhx5u), these rods could
be used to weld copper. Has anyone used these? In any case, I'm sure I
would have to buy a minimum of 10lb and I don't need that much.
I think I'm going to try brazing, though.
I have some Stay-Silv 56 from another project. Would that be a good
alloy? Or should I use their phosphor copper alloy? I guess one would
use the phosphor copper for better color matching? However, using the
staysilv 56, I would only have to get the copper to 1200F instead of
1400F.
If I braze the copper bars, would a mitre joint be the appropriate
joint? It seems there would be more surface area than a butt joint, but
it still seems like there should be more of a mechanical fitup for
brazing.
I think that a lap joint would be the best joint for brazing.
Wayne Cook
Shamrock, TX
http://members.dslextreme.com/users/waynecook/index.htm
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