Hi,

I have a problem with finding out wheter or not titanium alloy is suitable for lug material, there is a method of basically laser melting or something high accuracy lugs, but nevertheless is it suitable for lug material?

The lugs would be silver brazed, and the tubing would be niobium(columbus spirit for lugs), which has very high melting point which is 2,469 celcius, perhaps I should use some other columbus tubing?
I am new to this and want to give custom lugs to a framebuilder for my custom build, but I dont know whether or not this will work...

Please help me out with this one... thanks a lot!!

In general, Ti is not suitable for brazing. Apparently Pino Moroni figured out how to braze Ti to Ti, but I think the secret is buried with him. Probably involves inert atmosphere hearth brazing. There was a thread here recently about this

this might solve the titanium brazing problem?

https://www.superiorflux.com/titanium_brazing_flux.html

you can try it, how are you going to make the lugs? I don't see this as a useful exercise unless you want to win a prize at NAHBS.

As you said, the secret died with him but I've long suspected that he pre-plated the parts of the Ti which were to be brazed. I'm guessing nickel. An ordinary brush finish would make this undetectable.

Tactically, you could double the ends of the tube, miter both Ti tube, Ti sleeve Lug,

then perhaps lay down a bead. welding both in the same pass, for the Look of lugs..

https://www.titanium-brazing.com/publ...opy2-19-07.pdf

Lays out the advances fairly well.

This method of brazing bits (plating then brazing) onto a TI frame is what Eisentraut suggested be done when he first saw the Teledyne frames way back when. Instead they necked down the diameter so a,then, current banded shift lever set could be used. Andy.

the necking on Teledynes was stupid. I bet they could have figured out a way to make their own fittings, at the time everyone pretty much equipped their bikes the same way

Of course, the main stupid thing they did was make them out of commercially pure Ti. Wish they knew what they were doing

Why not ask builders who work with Ti everyday? Firefly manufactures and uses Ti lugs on some of their frames and Strong Frames works with Ti everyday- just to name a couple. It's hard for me to fathom why you'd want to produce the lugs and then turn the rest of the project over to a framebuilder. If you are capable of making the lugs... just sayin'.

that's my reaction, if you make the lugs then it seems like that's the same amount of work as making a bike. Unless the lugs would be produced by some process that is only suitable for lugs. I think the last thread about this type of thing I mentioned the Ti lugged carbon bike that Bruce Gordon made. He said he wouldnt' do it again because it was too much work. I guess there are counter-examples like the Firefly or the Serrota Ottrot.

Freddy Parr tried working on this some. While its possible to braze faces on the teeth of sawmill blades, he couldn't find a way to braze tubes together. His focus was less on Ti lugs to steel (why?) and more to do with brazing Ti tubes.

Not clear what the cost/effort of creating the Ti lugs would gain, and that's before considering the feasibility of brazing them to steel tubes.