In reading some stuff on early automotive history, there was some
discussion of late 19th century bicycle history. It mentioned that the
steel tube frames were brazed in 1880s and 1890s.
I know that what we think of as welding today (arc & gas, as opposed to
anvil welding) was developed near turn of century. How about brazing.
How old is brazing?
I've read in old books (100 years, plus) about alcohol "blow lamps". The
connecting agent referred to was a form of silver solder. The operator's
breath created a small blast of sufficient intensity to create a high
temperature. Presumably, this was early brazing.
Hard soldering (silver soldering) is ancient, a trade of the jewellers
Theophilus ("On Divers Arts", 12th century) describes brazing. His
description is for making rings of iron by wrapping with copper (also
with bronze) and then heating in a forge.
Brass (at first it was termed "latten") isn't a common medieval metal.
It was made by an expensive cementation process from copper metal and
zinc ore, as zinc itself couldn't be reduced to the metal. In the 16th
century, brass began to be produced by direct alloying of the two
metals. Agricola (De Re Metallica) describes this as a relatively new
process and in the UK it began at the well-known Tintern Abbey wire
works. As brass is ductile, wire making was an early demand for it.
Throughout the development of firearms, brazing was a common way of
joining iron or steel pieces.
"Modern" brazing dates from the popular use of mild steel (later
19thC) as a replacement for wrought iron. Steel is relatively harder
to forge weld, so this encouraged alternatives.
The Romans had a significant brass and bronzeworking tradition. I
imagine they used it for brazing too, but haven't checked the
AFAIK bicycles are for the most part still brazed, There may be some
hi-tech stuff out there that is all welded. Brazing is quick and easy
and provides a strong joint and is well suited to assembly line processes.