heat control

Fillet Brazing and lugged construction are often treated as two totally different worlds. I find that a little odd since they are both rooted in same- they are each methods of joining metal. While the techniques of each are different the end result achieved for both is an effectively brazed joint.

Some ciclisti conoscenti may debate whether lugs have all the soul*, or whether fillet brazed frames looks too mean,* but I like to think that as a framebuilder it’s my job to use an appropriate joining method and make the frame look nice. I like and use both disciplines.

Leon’s track frame is constructed with some shaped aero tubes, so fillet brazing was certainly an option. A lugged frame was also an option, but would have to be fabricated around sheet metal “lugs” due to the profile of the top and downtubes. This approach works well, as everything from early clunkers to Mark Nobilette MAX masterpieces have used some sort of stamped, sheet or roll-formed lugs. In order to keep the cost down, and to make for a more timely delivery, this frame is being fillet brazed.

Fillet

On account of the tubing profile, it’s pretty clear where each main tube stops and the headtube starts. I wanted to try and make this transition a little more smooth, so I used a little larger (and taller) fillets than I typically would. This will give me more surface area to work with when filing away, so I can try to get a gentle sweep from tube to tube rather than an abrupt edge.

This tubing is Dedacciai Zero LTP (dt), Columbus Mega (tt) and Dedacciai ht. on account of the thin walls in the tubing, heat control was paramount to not cooking these joins. I used a harris 205 tip to preheat each joint, then switched to a 203 for adding the filler. “flow the tack and go” as Dave Kirk would say.

i’m happy with the results. Leon came over to check it out as well, and it was great having him down at the shop. Some Phils are on their way to Velocity, and they’ll be meeting up with the B-43s like a “missed connections” ad soon!

*actual conversations I overhead at NAHBS

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