Then onto the welding table, heat sinks are put into the HT, ST, and BB and TIG welding of the front triangle takes place.  TIG stands for Tungsten Inert Gas.  The welding "torch" uses a tungsten electrode that is sheilded by a flowing argon (inert gas).  The argon keeps the area free of contamination while it is molten and cooling down.  The welder has a foot control like a gas pedal to regulate the electric amperage and therefore the amount of heat and puddle size.  The pulse control pulses the amperage to maximize weld penetration with less heat.  So I've got the right foot on the pedal, my left hand controlling the torch, and my right hand feeding in the filler rod.  It's a lot going on, but everything is working together.  It takes great care and smoothness to do the weld, as the tubing is very thin and the welder is very powerful.  To me, it's magic, seeing the small molten pool of metal, and manipulating it carefully around the joint.  The metal is heated for a short time, and the use of the pulser and the heat sinks means the heat affected zone is very small.  Take a look at the picture at the right and notice how small the heat induced discoloration of the tube is at the joint.

Another note: welding takes place using a sequence to balance the distortion that occurs from the heating and joining of the tubes so that the frame maintains alignment.  A couple of times during the welding process I'll put the frame back on the surface plate to make sure it's staying straight, and can make adjustments to my weld sequence to keep it straight.

Okay, front triangle is done, time to work on the chainstays.