I've been busy. Its a good thing I like a challenge, it has definitely been that. Its been about 20 years since I did anything substantial with an oxy touch, its coming back to me. I started with something easy, the internal cable guide for the brake cable, getting the brass tube though the hole wasn't as easy as you'd think it would be, its not even remotely flexible. I put a curve in it by bending it over the edge of the bench then persuaded in though the holes (read hit it with a hammer in a controlled fashion). The rest of the operation when as planned but I did discover how easy it is to over cook the flux with oxy-acetylene.
Hole in the top tube ready for the brass tube
Moving right a long and since I has all the tubes cut I put it all in the jig, took it out, fluxed up the top two lugs and gave it my best. I was given some good advice by Peter Bundy, "just keep feeding in the filler, you need something to file off", well the filler, which is 45% silver isn't all the cheap, but its only money. The first two are not what I would describe as my finest work, but its not going to fall apart. You would normally start by soldering the seat tube into the BB shell, but as the BB shell has a lot of metal in it its a bit harder to do, thus starting at the other end. As my head tube and seat tube angles are the same you can get the down tube BB combo in after the top half is together.
That was yesterdays effort, today, after a ride I put the bottom half of the front triangle together. There had been a few issues with getting it to line up in the right place with the required angles, something was out slightly. After a closer inspection I filed a bit more of the down tube at the head end to correct the angle, the lug was slightly out, buts that nothing a hammer can't fix. I got it all together, pinning the down tube into the BB shell with a nail, drilling a hole first of course. This was to stop the down tube slipping whilst I soldered it. The frame needed to be pushed into the jig to get it to align, I didn't see this as a problem.
Starting with the lower head lug with it clamped to stop it sliding down the head tube I soldered half of it, this was so I could beat it into submission and correct the angle. After all they are castings and don't have that much metal in them so I may have bent it when I was filing out the inside surfaces. With that fixed I moved onto the BB, which went off without a hitch. I'm getting better at this.
So I let it cool down in the jig hoping that when I took it out it would remain straight, and would you believe it, it stayed straight. Now just a whole lot of filing to clean it up.
Here's the finished pics, don't look to closely, I'll be cleaning them up a bit more.
Here is the frame back in the jig with the rear drop outs in the jig. I bent the dropouts so the exit angles are correct (or close to) as they are cut from plate and are flat. Next job is the rear triangle, starting with the chain stays. The chain stays are a bit long, it may have something to do with using track dropouts, they are a bit longer and the stays can only be pushed so far into the BB shell as they are only round at the end, ovalised in the middle, so the stays need to be cut down from both ends. Luckily I'll only need to cut 15mm off the back so I don't expect the internal diameter to change that much so attaching them to the dropouts shouldn't be a problem.
