Reheating joints

[AMBikeCo]

Hi folks

I finally started on my first frame (HT-DT lug brazed yesterday) and it went well as far as I can tell. Bronze brazing.

I do anticipate making a mistake at some point though, and feeling the need to reheat a joint to correct a flow issue or tidy a shoreline.

Tubing is standard cromo with 0.9-0.6-0.9 walls.

How many times would I be able to safely heat a joint with that basic tubing? One re-heat? No re-heats?

Would like to know in advance before I do something silly in the heat (.... sorry) of the moment.

Thank you,

Colin Tuff

[e-RICHIE]

The business end of a lugged joint is really the interior where the tubes kiss. If what you’re asking about is shoreline related, just make sure the surface is clean and use a light flame to run the filler around at the edge.

That said, I can’t literally answer the question. No joint should be reheated to the degree that it was during the initial pass. Touching up a cosmetic void, should you have to - well, see above.

PS Can we get a surname added to your comments here?

Thank you

[Thomas Norton]

As a real beginner my question is what happens if you reheat a joint a second or third time?
Thanks!
Tom Norton

[Andrew R Stewart]

I don't think this type of question has a hard answer. How hot and for how long and how evenly was the initial heat cycle? How about the second or third ones? So many people will go back and touch up shore lines or fillet pocks. We don't hear of lot's of hand built bikes cracking or otherwise failing though. So my answer is that catch all, it depends. Andy

[AMBikeCo]

Thanks guys. I have a tendency to get a little OCD with brand new skills until I feel confident with the quality of the work, so I often re-do things to death. It's a confidence thing, I guess.

I will try to rein in my obsessive behaviour on this occasion though.

So good to have a place like this to ask questions. It's easy to feel isolated out in my workshop alone for days on end.