The NEW Project: Part 1 – Steeling Myself

Update (Years Later!): Despite the opening sentence, I never completed this project. I keep this post alive only to remind myself of the few times I’ve actually exercised good judgment.

Cosmic forces have been set in motion and there’s no turning back.

I’ve officially kicked off The New Project (dang…I need a cool name for it. Any suggestions?) by (1) spending money and (b) doing some initial “research” (12 minutes on Google).

First, the research part. I operate under the theory that if you really want to know what time it is, you need to understand how a clock works. Well, not really, but I do realize that when it comes to melting metal — especially expensive metal — a little knowledge is a dangerous thing. So I’m researching steel.

I began by confirming with the bike’s builder — the eminent recumbent pioneer, Dick Ryan (yes, I have his email address) — that my tandem’s frame is a common alloy known as True Temper 4130 steel (often referred to as cromoly or CroMo, as it’s a mixture of chromium and molybdenum alloyed with your basic iron). CroMo has a melting point of around 2600°F. That’s an important number to remember, more so for me than for you, of course.

I think I’m going to enjoy the research part of this project, as it’s leading me to pearls of wisdom like this, from a primer on bicycle frame materials:

From now on, in the bicycle lexicon of this series, I’ll be using 4130 and CrMo interchangeably, even though not all CrMo’s are 4130. CrMo is by far the most common of all the steels used to build high- quality bicycle frames. And I’m making an assumption that the readers of VeloNews who ride steel frames aren’t riding Muffys (That’s the generic name for the Murray-Huffy style of bike you can buy at those fine American institutions like Kmart and Wal-mart.) Muffy-grade steel is barely above rebar on the steel “food chain”; rebar is essentially a blend of melted 1956 Chevys, washing machines and shopping carts.

Muffys. Heh.

I also did some reading about the art and science of brazing, learning that unlike with welding, the metal to be joined is not melted. In fact, melting that metal is a Very Bad Thing, something to be avoided at all costs.

Instead of melting two pieces of metal together, brazing employs the capillary action of the metal pieces to fill the joint between them with a different melted metal. The filler metal actually penetrates the matrix of the base metal, resulting in a solid joint that is sometimes stronger than the original metal parts themselves.

Unless you do it wrong, then the whole thing collapses in a soggy, steaming heap and you’re disgraced for life and very likely irreparably maimed in the process. But let’s not dwell on the negatives, shall we?

OK, enough research. Time to spend some money. But not much; brazing rods are remarkably cheap, less than $2 each, and readily available at your hometown Home Depot. For The New Project, I chose nickel silver rods by BernzOmatic. (I was initially somewhat put off by the skull and crossbones on the package, along with the words “Caution: Poison,” but I’m pretty sure that just means not to eat them. Or something.) I could have gone with the somewhat cheaper bronze rods, as either type will apparently do the trick. Again, according to Dick Ryan, when I asked which one he recommended:

Doesn’t much matter, we used both.

Dick’s a man of few words.

Now, if you went to the BernzOmatic website (and you should have), you no doubt noticed that these brazing rods have a working temperature of 1680°F. According to my calculations, that gives me almost a thousand degrees of leeway before I do the Very Bad Thing mentioned above. Anybody, even the most mewling n00b, can operate within a thousand degree tolerance, right? I mean, that’s like boiling water 5 times, sort of. Still, given the fact that an oxy-acetylene torch burns at a temperature of around 5,600°, overheating the base metal is my biggest concern. That’s why I need to practice first.

Anyway, it was a very productive day, project-wise. (I apologize to my clients who were expecting to get some work out of me.) Let’s recap:

  1. Gain basic knowledge. Check
  2. Buy basic materials. Check
  3. Ignore basic warning signs. Check
  4. Develop cool project name. Pending

Stay tuned for the next exciting installment, as we take a hacksaw to a perfectly good bicycle frame.

Technorati tag:

4 comments

  1. Brazin’ Bicycle Hack, perhaps?
    Has lots of puns at various levels, which to me is always a good thing.
    I think maybe the skull and crossbones was there to indicate that it’s a cool accessory for Harley bikers. No worry about poison necessary. 🙂

  2. I like Brazin Muffy, a blend of yours and Beth’s suggestions.
    Having done the Very Bad Thing with silversmithing (albeit at much lower temps), I do caution you to be very careful. Going from 1600 and 2600 degrees probably takes about 5 seconds. 😉

  3. I was all ready to suggest MAPP gas instedad of oxy-acetylene, but it turns out that only saves you like 400 degrees.
    I can’t find the burning temp of propane anywhere. Though, to go from manually mixing highly explosive gasses to a little propane torch might take all the fun out of it.
    I’ll leave the metalworking to you. 🙂
    One more vote for Beth’s project title, btw – that’s great!

Comments are closed.