Hi Keith, You are absolutely correct ! That is what I explained,
basically
...... You BRAZE with the brass rod & flux ( heat the business end of the rod
and stick it in the flux ..... that makes the flux stick to the rod .) I
have seen
guys try to braze without doing this ) You WELD with steel rod, when welding
on steel, of course, and melt the two pieces being welded into one, working
the bead with the angle of the tip, and filling the gap / creating the bead
you
desire by feeding in the rod . When BRAZING steel, as you know, you
bring the temp of the parts close to a dull red, where the flux and brass rod
flow to fill the joint ..... and this is NOT WELDING , as I stated . The
welding has superior strength, as you found out when your headers
developed cracks along the brazed area . I found out brazing would
crack on my collectors many years ago ..... they are subject to the
vibrations from the sound waves ..... so I gas welded them and that
ended the problem . Welding header flanges on the inside is a little
tricky and requires grinding and filing afterward . A nice bead on the
outside looks good, tho, I think . The flange problem is always there
because it is considerably thicker than the tubing . On one set of
headers long ago, I paid a guy to TIG the flanges inside to the square
to round transition stubs, and then gas welded the rest of the round
tubing and collectors . It's a lot of work to build your own headers,
unless they are the "out in the open" short stacks usually found on
blown dragsters . There are so many well built headers available
nowadays that I do not think it makes much sense to make your own
unless you just WANT to do them, or you HAVE to custom fit them,
as our installation of the rat motor required . Making headers from
bends and straight pcs requires more measuring, fitting, cutting, filing
and beveling time than the actual welding time, and you take the
headers off and put them back on so many times you think you' re
gonna wear out the threads in the heads ! The jigs used by the
manufacturers for production models make it somewhat easier ......
but I' ve never had to resort to jigs . You can weld short pcs of angle
iron to the ends of vise grips to hold straight pcs, and the flat side
of bends ( 90 * from the curve ) together while tacking them ..... this
helps a little . As to the MIG wire being hard, Howard Nafzger is
right ..... there is an EZ grind wire available now ..... I only learned about
this while on a visit to Darrell in the Bay Area in 1999 . I like to check
out
welding supply places, among other places like speed shops, etc., and
they had it at this weld supply house right next to where all those
Liberty ships were built, during WW II, by Kaiser Shipbuilding, in
Richmond, California . The " souvenirs " I bring home from my trips
usually come from these Bay Area tool stores / weld places, and not
from where Mary Ann buys her trip mementos ..... isn't it funny how
women don' t get too revved up over tools or speed goodies, etc ?
Well, now that I think about it .... I don' t get too excited over
the shops she likes to frequent ..... but that' s how it ought to be,
right ? WHAT has this got to do with gas welding ? Nuthin '.
You BUY your headers, anyway, so you' re all set !
Bruce, hiding out at my 'puter in this cold spell .....
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