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View Full Version : Weld over brazing


Michael Horowitz
January 5th 09, 12:37 PM
This is not aircraft related.

I did some brazing on a tank and then later decided it would have been
easier to have welded.

I read somewhere that one should not attempt to weld over brazing.

I assume becase the brazing material melts at a lower temp than the
base metal, that welding over a braze would cause the brazing material
to boil away, spattering filler material.

Is that analysis correct?

I assume the recovery is to remelt the brazing filler and wire-brush
it off???? - Mike

January 5th 09, 03:39 PM
> I assume the recovery is to remelt the brazing filler and wire-brush
> it off???? - Mike

I've never had much luck with that method. I tried it back in my
bicycle building days and gave up trying to
"salvage" a brazed joint. I may be way off in the actual physics of
the matter..... it was my observation that at welding temperatures the
brass would alloy with the base metal and while I might be able to
make a nice looking weld - they were without exception very brittle
and failed.

Now if I run across a brazed joint that needs repair, if I can't
repair using brass, I either cut away ALL the brazed zone and weld or
junk the part.
==================
Leon McAtee

Orval Fairbairn[_2_]
January 5th 09, 05:17 PM
In article
>,
" > wrote:

> > I assume the recovery is to remelt the brazing filler and wire-brush
> > it off???? - Mike
>
> I've never had much luck with that method. I tried it back in my
> bicycle building days and gave up trying to
> "salvage" a brazed joint. I may be way off in the actual physics of
> the matter..... it was my observation that at welding temperatures the
> brass would alloy with the base metal and while I might be able to
> make a nice looking weld - they were without exception very brittle
> and failed.
>
> Now if I run across a brazed joint that needs repair, if I can't
> repair using brass, I either cut away ALL the brazed zone and weld or
> junk the part.
> ==================
> Leon McAtee

Never form a puddle in the base metal when brazing! THe braze will mix
with the base metal and form a poor alloy.

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