"Rex B" wrote in message
...


There also is a welding book that specifically talks about welding
space
frames, _Performance Welding_ by Richard Finch. It's pretty good.
Ignore
what he says about brazing 4130. He's wrong about that.

What did they print that was wrong?


He says that brazing 4130 can crack it. I did a real research job on it
and
found that no one agrees with him, including the old author of _The
Brazing
Book_, who did brazing research for 4130 aircraft frames during WWII,
and,
more recently, some high-quality custom bicycle builders who
bronze-braze
4130 all the time.

There was some speculation by those experts about where he may have
gotten
the idea, but I forget exactly what it is. I tried to contact him
through
his publisher about it but I never heard back from him.

I've had a couple formula cars with brazed 4130 spaceframes. After 20 or
so seasons, no cracking evident.

That's what several people have said. I remember now what the speculation
was: Someone said that if he grossly overheated the joint, it could be
weakened by intergranular pentration. The speculation was that 4130 may be
somewhat sensitive to it, but no one reported that problem from actual
experience.

--
Ed Huntress