Wednesday, April 7, 2010

Fire!

At long last, Olivier and I have made fire. There, at right, is what appears—through the sober lens of my camera—to be a shockingly hot flame. Shockingly hot is not a bad thing for us. If anything, we were afraid our oxy-propane (with oxygen from an oxygen concentrator) setup wouldn't be hot enough.

We really had no idea what sort of flame to work with, so we're going to research that a bit. In Doug Fattic's class I learned what to look for in an oxy-acetylene flame, but this one is totally different. For example, I could only find one cone: not the two distinct cones I'm used to in the oxy-acetylene flame. Hopefully this isn't because, for example, we're not getting enough pressure from our oxygen concentrator.

Our first brazing experiment was the one pictured at right: we just melted brass on a piece of scrap metal. Having succeeded in this, and dropped a big glob of brass onto the floor, where in shattered and hardened into numerous lovely brass balls, we moved on to project number two.

This related to my lugs. Since they're pressed, they leave big gaps at the transitions. For silver brazing, this just won't do. So we dumped a lot of brass in there. I'll file the sockets clean, and will be left with nice tight transitions, appropriate for silver brazing.


In other news, earlier today I carved my shapes into my bottom bracket and fork crown. The BB (from Ceeway) now has my "signature" lug shape in all the sockets. I also drilled holes on the sides of the seatstay sockets, to replicate the drilled-out spoons on the lugs. The BB doesn't look great in that photo, but you get the idea. The fork crown (a beautiful Pacenti Mitsugi) received similar treatment. The inside tang is like the point on my lugs; and viewed from the side, it has the same "double-swoop" profile. I think it looks great. I also filed off the reinforced area for a front brake bolt. This bike will get brazed on centrepulls.


Also, I got the rear derailleur for Bike Number Two today: a 1972 Huret Jubilee. I'll write a post soon about this planned second bike. For now, here is the lovely Jubilee screwed in to a Della Santa-branded Campagnolo dropout.

1 comment:

Papa said...

Lookin' good Chief. O/P is definitely a different animal than oxy/acetylene, but well suited to the task when you get used to it. So far, I've cut my oxygen and fuel expense, literally in half using the same setup. And no more lifting and hauling those back-breaking 75# bottles anymore. -Papa-