I’m halfway through a 2-week internship in a titanium frame manufacturer which I’d prefer not to disclose. I’m having some concerns about some of their procedures, and was wondering if any experienced titanium welders would like to pitch in to give me some perspectives.
(Sorry for the long read, I always have millions of questions regarding framebuilding)
I must say I have zero experience in framebuilding, or even in any professional metal manufacturing, I don't mean to throw any shade or bring any negative comments towards them. I can only base my impression on research and readings I’ve done prior to the internship, so I'm giving them the benefits of the doubt and am just seeking for alternative point of views. But I have a couple of examples that made me raise my eyebrows:
I feel like I’ve read so much about how everything needs to be squeaky clean when working with titanium, I guess similarly to stainless steel. I’ve heard of companies who would have completely separate workshops for working on these different metals, with a completely different set of tools and even welding machines and torches, tungstens and all. And this place is no where near this. I’ve had to build a basic rectangle frame for a tank out of mild steel square tubing and they just made me do it (cutting and grinding) next to a bunch of titanium tubes and equipment. They do have a belt sander only for titanium, but it’s right next to a bench grinder they use for everythin. I’ve worked in professional kitchen for almost a decade, so dealing with allergies and handling raw meat and fish, I know about cross-contamination. I don’t know if it’s anything alike for frame building, but this definitely wouldn’t pass the test in a kitchen.
Next for forming the titanium tubes shapes (oval, pentagonal, crimps and dents) we were using a compressed-air press with steel mold that are rather imprecise despite being CNC machined. Some don’t really hold in place or need a whole bunch of steps and other tools to make sure everything is in place. We're using a bunch random and eyeballed rubber and plastics shims to act as mandrels (not sure this is the right term) inside the tubing to prevent buckling. For crimping the drive-side chain stay of one model, measurements are taken from a print that don’t quite match the actual stay and I had to use a manual press with just rectangular blocks…with nothing holding it in place or to make sure the crimp is in plane with the bend (except than my “advised” eye). I’m not saying that everything needs to be computerized or have expensive jigs and molds, but I cannot imagine that there isn’t a better and not overly complex or costly way to do this and insure precision and repetitiveness.
Then I saw raw welds on the frames and they all have coloration around the weld and/or HAZ. Colors go from light brown to light blue, which I was told is either a sign of too much heat input or the material is not properly cleaned. The owner and only welder says it’s normal and that he’s never had problem with frame failure. I haven’t got to shadow him around a complete build yet but from what I could gather he seems to have an adequate welding setup (internal purge, pulse mode, big cup and gas lens).
Again I really don’t want to talk shit about them or be disrespectful, I’m just trying to put things in perspectives, as a lot of it doesnt seem to correlate with my former assumptions of what a titanium workshop should be, assumptions that were only based on internet information mostly gathered from forum such as this one, and no first-hand experience. Am I being over-zealous about all this, or does it looks like lousy work? I do think the frames come out well in the end, safe and true an all. But when you’re selling 4000$ frames made out of such an expensive and capricious metal as titanium, I thought I could expect tip-top equipment and procedures, otherwise why even bother?
I hope I’m not being too harsh on them. I’m asking out of curiosity but mostly because when we first met they mentioned the possibility of a job after the internship. I was already uncertain because of other personal reasons, but now this makes doubt even more. I would appreciate any opinions on the subject!
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