Roody's Lugged Frame: Part 2 - Brazing the Tubes

Day 2: Brazing the front triangle

    After prepping all the tubes and lugs I checked all the fittings. You basically want all of the tubes to fit tightly into the lugs, but one that can still be pulled apart by hand. That way you get the tightest fit, with enough room to get a good amount metal in there to secure the joint.

    I put on some music and set up the brazing torch. I find it is good practice to take down and re-setup your torch every once in awhile. That keeps you aware of any problems with hoses or fittings, and helps you remember where your gauges should be set. The oxygen should be around 5 psi, and the acetylene/propane around 10 psi After checking all my fittings and pressure gauges, I grabbed my gloves and goggles and fired up the torch.

Getting the flame you want is pretty easy; barely open the fuel side, ignite the fuel, adjust until there is no gap between flame and tip, slowly add oxy, adjust until you have a whitish inner cone with a rounded (not pointy) tip, and a larger transparent blue flame surrounding it. [Need more help? Check out brazing vids on youtube]

   Starting with the seat tube and bottom bracket joint, then the head tube lug and top tube. once those were secured, I could put the rest of it together and align it on the bench. Once that was all in place, and aligned well, I set it up in the stand. One by one, each joint was separated, flux, and put back together.

  After double checking the alignment, mostly by eye, and a little with a caliper, I brazed the rest of the joints, and finished the front triangle.

   After putting the fluxed joints in a water bath, and cleaning up tools, I scrubbed off the flux with a wire brush.After re-checking the alignment, and being happy with it, called it a night.

Day 3: Rear triangle

Roody came out to the shop for the next session; fitting, aligning, and affixing the seat and chain stays.

   We started by prepping the pieces, then bending the dropouts slightly to curve inward, and set up the rear triangle. Everything fell perfectly into place on the bench. We used an old rear wheel to hold the dropouts in place, and a piece of plumbing strap to hols the seat stays in place. After checking the alignment, brazed it all together, bathed and scrubbed it.

   The basic frame was finished! Now to order the braze-ons!

[to be continued...]