Curt,
Regarding brass brazing and 753, and what Dave Moulton said at the
Cirque.
Moultons 753 test for certification was silver brazed. It did
pass "the test" from Reynolds, as one would expect. The 753 test kits
were provided by Ted Kirkbride, as he wanted each builder who was
working for Masi to be Reynolds 753 certified for various reasons;
(I'm pretty sure none of the Masis any of these people built were
made from Reynolds 753). He had 4 test kits; one for himself, one for
Dave Moulton, one for Dave Tesch, and one for me. The other three
brazed their samples and passed the test and all were certified. I
wasn't working for Masi, I was independant; so I had no need for the
753 test. I didn't see the approiateness of that material for the
type of frames I build, not then nor now nor any time in between. I
still have a strong preferance for the standard Reynolds and Columbus
of the 70's. Overall it seems to be the most versitile and practical
tubing for the type of frames I build.
So physics are still intact. No one is likely to pass a 753 brazing
test using brass rod as the filler. Otherwise, what would be the
point of the test, as Curt suggests?
Brian Baylis La Mesa, CA Again, I was there when it all went down; and I remember the details.
At 05:26 PM 7/19/2006, Jon Schaer wrote:
>At 06:15 AM 7/19/06 -0500, John Thompson wrote:
>
> >Using brass requires higher temperature and thereby negates the
> >advantage of the heat treatment. Use brass and all you have is a
> >light-gauge 531 set.
>At this year's Cirque, Dave Moulton said that he always used brass
for
>753. Thought that his torch flame and brazing speed avoided
overheating.
>I think he even said his sample passed with Reynolds.
Nah, it's about temperature not time. If he got it hot enough to
melt the brass, he got it hot enough to undo the heat treatment. The
heat treatment was the thing the Reynolds folks were looking to
preserve. Hence the recommendation to silver braze. Silver melts
before the heat treatment goes away. I mean no disrespect to Dave
but physics are physics. With that said, plenty of 753 bikes were
successfully brass brazed. Why? I don't know but frame builders are
a stubborn lot. Tell them you can't do something and they'll do it
just in spite. I use 753 on a weekly basis. Silver brazed, of
course.
Curt Goodrich
Minneapolis, MN