Ybarrola and Persechini steel lugged frames
are built the old fashioned way, mitered by hand, pinned
joints and silver brazed.
Mitering by hand is a fast and very efficient
operation. Using a file and a template or lug as a
guide, a gap free miter can be done quickly. When
doing a one off custom steel frame there is no need to
spend lots of time setting up a milling machine and then
risk tearing thin walled tubing with power
machinery. There are times when a milling machine
is helpful, but in most cases it is not necessary for
custom small production bicycle frames.
Notice the top tube head tube miter to
the right. The top tube fits the lug perfectly.
This will ensure a gap free fit with the head
tube. Gap free miters are what
give the frame its strength and help to ensure
I pin my joints because it allows me to make a better
frame. With pins I can make a frame more
consistently and with better alignment.
A frame should be
brazed outside of a jig to let the frame expand and contract
during brazing. To braze outside of a jig, the frame
must be held together and in alignment. It can
either be pinned or tacked. Tacking involves doing
small "welds" around the lug and tube.
After tacking, a frame can be brazed outside of the
I choose to tack my joints
mechanically.....with pins. The pins hold the
tubes in alignment and allow me braze outside of the
In my opinion heat is the enemy of steel
tubes. Of course heat is needed to join steel to
steel, but I believe that using as little as necessary
will allow the tube to retain its original characteristics.
Using silver solder allows me to braze a
frame at much lower temperatures than brass brazing or
welding. 56% silver melts at around 1,200F, brass
melts at about 1,600F and tig welding is performed at
even higher temperatures. The "critical"
temperature of steel where steel can change
characteristics is around 1,800F.
I choose to have my frames "wet
painted", not power coated. It costs more,
but there is no better way to show off lugs. I am lucky enough to
live in San Diego where Brian Baylis and Joe Bell are the local painters.