Titanium - lugs and tubes?
 

Hi all, total noob here… not a welder. I know Ti is TIG welded to keep it “pure”… wondering if you can build a Ti bike with lugs or if inert gas makes that a no no?

thanks, -tim

Welcome to the forum

Back before TIG welding became acceptable for bike frames, some people oven brazed titanium with lugs. So it is doable. It's just that there is no point.
Pino Morroni main

Why is there “no point”?
I’m interested in a Ti frame… I’m interested in lugs… know anyone who would do it?

Well since you opened the door... why not you? it might take a few years to learn and stumble enough to get it right enough to be safe.

One might be able to 3D print or weld up TI lugs (and others have done this) then join to TI tubes with an adhesive. I think you'll find more carbon tubed examples though.

I also think that most will find the efforts to be large and the gains (other then the cool factor) will be small. Andy

Thanks Andy,
I am thinking “why not me”… so I’ll keep asking questions. Why adhesive, why not brazing? Silver braze melts at low(er?) temperature… silver braze on Ti lugs and Ti tubes?

I said there is no point because it adds a very large expense for no benefit at all. And Pino Morroni and Cecil Behringer were very experienced at what they did. This is not a beginner project, it's a very advanced project. Otherwise people would do it just for style points.

My link is bad because they don't use https. Pino Morroni main

Brazing brings all kinds of issues around oxidation of surfaces and changes to tube material states. Bonding with a "no temp" glue avoids much. This, besides the chemistry/wetting out/compatibility in brazing TI:) You need to do some more homework. But that's some of the FEW years of research and learning I mentioned. Andy

I don't think a framebuilding forum is the right place to start your journey. Ti fab is your first challenge. No one makes Ti lugs so you're going to have to make them. You'll need to know how to cut and TIG Ti tubing in 1mm walled configuration. You'll probably also need to know how to machine Ti to make the sockets fit the tubes correctly. You may want to make 1 set of lugs in steel (which is much easier) to get an idea of the difficulty of just this step. Any fab shop would be able to do this for roll cages or any number of other purposes. Once you can cut, miter and TIG Ti. Then you'll need to figure out how to braze Ti. Many struggle to braze steel without significant practice. Once you've figured those things out, a framebuilding forum is a logical next stop for information on how to apply these skills and knowledge to frame making.

Having said that, Bruce Gordon did a couple glued Ti/Carbon bikes and he was as experienced as it gets when it comes to bike fab and brazing (silver or brass). He chose glue and was certainly capable of brazing anything that could be brazed. It's not unreasonable to think he may have even known Pino/Cecil or possibly had access to their information and could have gone that route if he thought it had merit. Somewhere there is an interview where he talks about the difficulties he ran into just making the lugs and crown. Obviously his were quite intricately carved and shaped. I think he won something at NAHBS with that bike. Here's one article but there are several others:
Bruce Gordon in Two Bikes | RKP (redkiteprayer.com)

As far as I know, no one here is an expert in Ti fab so I would recommend you search out Ti fabrication experts to understand why no one in the world brazes Ti . I'm not saying there aren't any Ti builders here or folks who know a lot but I rarely see any posts about Ti bike fab and they are all TIG, not brazing. Also indicative is that when this question comes up, we all point back to a couple of Master builder/fab guys who managed to do it some 40 years ago when Ti was just being introduced to the cycling industry. There's probably a reason in there somewhere.

Please post up your progress/findings as it's very interesting subject.

EDIT: I don't know if 'no one in the world brazes Ti'. We just never hear of it and it. It struck me though that you may be able to start your research here: Brazing Fundamentals | Lucas Milhaupt Lucas Milhaupt has many brazing fluxes and fillers and likely would have some info on how or why you shouldn't braze titanium. I would send them an email or phone call.

It's an interesting idea and I had a look around on Google. People seemed to be saying you might need to do it in a vacuum-- the basic problem is Ti is very reactive. We know that if you TIG it you need plenty of gas and a back-purge. In fact some Ti parts are welded in entire boxes full of Argon (although not bike frames that I've heard of).

If there had been a need for this historically maybe the rods, fluxes and procedures you need would have been created. But we probably didn't start using Ti much until after TIG was already widely used.

When I took Eisentraut's frame building class he mentioned that he was a consultant on the Teledyne Ti frame project (Teledyne was a high tech company looking for a flagship product to gain publicity with and picked bikes). This consulting didn't last long and when later at the bike shows he saw how they handled some of the challenges he shook his head. Specifically he pointed out the necked down DT spot to allow for a band/clamped on shift lever (remember those:)) to be installed. Al suggested that they could have had a custom band produced in the size the rest of the tube was OR they could have chrome plated the TI tube surface then silvered the lever bosses to that surface.

So maybe the OP will be able to get his TI tubes and lugs chromed and then just silver the frame together. Andy (who will really like to see this done...)

I vaguely recall that Pino/Behringer did their brazing in an inert gas container. I don't think you can just purge for brazing, but maybe nobody had thought of that technique yet. My understanding is that there is plenty of ti brazing, but I think it's all done with an inert gas furnace. But I also recall that it took some experimentation. As I was typing this, it occurred to me that the experimentation might have been pre-loading the joints internally with the correct amount of filler and also possibly getting the heat distribution right.

You can get titanium lugs made by a 3d print shop. At least this is true if you are independently wealthy, you are talking the kind of money that will buy a pretty nice custom ti frame. There is also the possibility of machining and welding lugs.

This company says you can use their flux in air to braze titanium. Just don't cook the flux.
https://superiorflux.com/products/br...-brazing-flux/

I took UBI's first titanium welding class in 1992. I took it because at that time I was afraid steel might have a limited future life and I didn't want to be left behind like a blacksmith when people started buying automobiles. It was taught by Gary Helfrich who figured out how to TIG weld ti frames and started Merlin with a couple of others. I was just chatting with him last week end at the Philly show. He is good friends with Marc that runs Paragon Machine Works. Anyway brazing titanium became an interest of mine. I started by just wanting to braze on ti bits to a ti frame instead of welding them on. I thought it would give it a cleaner look. I have never been a fan of the beaded look of TIG welding. I thought it would be cool to make a lugged titanium frame because I liked the look of lugs.

My research including going to the annual welding show put on by the AWS (I think that stands for American Welding Society). Anyway I asked around and discovered it has been done. They even had some literature on it. I went to a seminar at the show about brazing titanium that was attended by about 15 people that all seemed to know each other and I seemed to be very much the odd man out. They belonged in the aerospace industry. The presenter never showed. Mysteries remained.

At one of those shows I was given a small sample of ti brazing flux made by the Superior Flux company. I tried it out with little success but the problem is that I didn't have enough sample materials nor flux to keep going. The surface of titanium corrodes in the presence of heat and oxygen and once that happens 2 pieces can not be joined together. That is why a shielding gas of argon surrounds the joint when it is welded.

Before Cecil Behringer died, he passed on his secret sauce recipe for brazing titanium to an apprentice. That apprentice passed what it was on to me as long as I promised not to tell what it was. Somebody else in the online framebuilding community has spilled the beans on what it was maybe 20 years ago. .

Eventually I completely lost interest in brazing titanium. I didn't like the ride of a titanium frame (even ones I made) nearly as well as one made with very light steel tubing. Steel has a "lively" feel while ti seemed "dead" (YMMV). Keep in mind I am talking about steel with a thin wall thickness of .7/.4/.7 mm and not more standard 9/6/9. Also I'm big into carving lugs and painting frames and so both aesthetics and ride quality entered into my decision not to pursue doing more with ti. Also I realized that the effort involved of making a ti lug would be huge and the return would not be worth it to me. Of course I encourage you to keep researching. Get literature from the AWS and any information from the Superior Flux company. They used to have one engineer that worked on that flux. He might be willing to talk to you.

Thank you all for your comments, support, encouragement and knowledge. I really am a noob... both to the forums and to any kind of welding or frame building. I have soldered copper for plumbing, and I did take shop back in Jr High... but that was ages ago and I was pretty bad back then. I certainly recognize that practice, practice, practice, is a good place to start... and probably not on something expensive like Ti Lugs!

A Ti bike is a grail object for me... though I should probably ride one before I drop further commitment or funds on that statement. My favorite bike to date is my DeKerf Prodigy (steel)... for sentimental reasons as much as anything else.

Thanks again... not to shut down the thread, but to let you know that I appreciate all of the responses so far.

-tim

If making a titanium frame is your goal, you might want to consider taking a frame building titanium welding class at United Bicycle Institute (UBI) in Ashland, OR. The cost of equipment required to make a titanium frame on your own is pretty high. Taking a class allows you to leave with a completed frame and that may fill your need. Or it may just get you started to make more frames. The equipment and skill required to make a steel frame is a lot less and in my opinion a more sensible place to start if you are on a journey to make more. As a steel framebuilding class teacher, it is, or course, to my advantage to say this but it makes sense to take a class over trying to figure it out on your own. It is easy to get discouraged and/or disappointed when it isn't obvious how to do it right or get better. And lugged steel frames can be beautiful.

this article has some interesting history of the lugged titanium frames. The Retrogrouch: Pino Morroni - A True Cycling Innovator
I'll do the inflation calculator, if those bikes cost $10k back then, that's $28000 now.

It has a picture of the bottom bracket, which must have been machined. Pino Morroni was a highly skilled machinist (you didn't have to listen to him long before he would tell you that :) ). But I am really curious how he machined such a complicated shape.

https://cimg2.ibsrv.net/gimg/bikefor...9fd2d63d75.jpg
Miyata made them in the early 90's.

That Miyata has bonded joints. I don't think there is a lot of bonded lugged ti any more, most people that use bonded metallic lugs now are making carbon bikes. But saying "most people" probably overstates their number a little.

And aluminum lugs.

Just as a side note I talked with UBI a few weeks ago. I took a steel brazing class last year and was wanting to do the TIG Ti class next. For a variety of reasons they are stopping their frame building classes and focusing on the repair/certification classes. The last frame class will be a TIG Ti class right after Thanksgiving 2021. I'm on the wait list along with what was described as 'many others'.

I loved my UBI frame class! I'm disappointed they are stopping. However, I completely get it. Mask/distancing/density rules in Oregon since the beginning of 2020 have really hurt them, cutting class sizes in half. And when you own your own business, you make decisions every day balancing profit vs. the work and junk you have to deal with.

That's too bad about UBI. I thought there are other people that teach Ti, but I didn't find any right off?

fwiw. this is a quote from a European member re aluminum lugged titanium "They have always been a very small part of the market. I do occasionally see lugged titanium frames show up from time to time but those are a no-go because they were epoxied together and the aluminum lugs have started to corrode by now, making it impossible to fix properly without spending a lot of money."

https://www.bikeforums.net/classic-v...appearing.html

https://www.ticycles.com/framebuilding-seminar

TiCycles in Portland, OR is the other one I know about. I have no personal experience, I've only read about them on the interwebs.

Okay, so that page says Dave will teach ti if you know how to tig a steel frame. Which does seem reasonable.

Yeah, UBI was setup to take people with no TIG experience and help them make a frame. But, the student has to be willing to fail a lot, get help, and learn. And the more manual skill they had, the easier the process.
Mostly I use MIG for random projects around the house, kinetic art, and when friends come by and say 'could you just put this back together for me?' But, I have some brazing experience and a little bit of aluminum TIG. I took the UBI steel TIG seminar and it was challenging. Round, thin tubes are more of a challenge than square 1/16th inch tube holding up my leaf blower in the garage. The more experience you have with metal, frame building, fabrication, and woodworking, the more enjoyable and successful you will be in the classes. And if I were teaching a TIG Ti class, I think I would want my students to be able to make a steel TIG frame as well.

I suspect this statement is more about galvanic corrosion between the tube and lug socket then outer surface corrosion. Specialized found out the expensive way about galvanic reaction between differing materials in a bonded frame way long ago. IIRC one of their issues was not having the proper anodizing laid down on the sockets before the tubes were bonded in. Andy (getting somewhat off topic here)