Corroded/cracking lug - how to fix? 531 tubing - images incl.
 

Hello all,

I have a late 80's Reynolds 532 frame here with a corroding head-downtube lug.

What are my options? I do have access to MIG and TIG machines at work and some pretty excellent welders that Icould convince to help if it was a thing. Is it as simple as that though? Just Dremel/file out the area and fill it up again, then work at it (round file, sand paper) until it looks good, paint, job done ?

Or?

I'd love to keep the original paint on unaffected areas if possible?

Excuse the mud, trust me, it gets more love, just what first looked like just a scratch in the paint (see dodgy paint touchup) has turned out to be a lot worse than originally thought.

I don't know what I don't know, so any tips appreciated :)

https://cimg6.ibsrv.net/gimg/bikefor...45e089f4f.jpeg
https://cimg7.ibsrv.net/gimg/bikefor...b63560320.jpeg
https://cimg8.ibsrv.net/gimg/bikefor...7b3b668d2.jpeg

It's hard to say but looks like a new lug is needed at minimum. You could try dremeling out the corrosion using a cutting disc to see what's going on but be sure to not cut down into the parent metal too much.

Hi, thanks for starting the discussion!

Like I mentioned, I don't know what I don't know, but was hoping to fix it in-situ, wondering if TIG would work, or does the dissimilarity of the braze filler and steel tubing cause an issue there?

Also I would have thought a new lug would require the full headtube to be removed ? (i.e. two lugs?)

there is a thread in C&V where someone cut back the lug and brazed the frame back together. I'm not sure how well theirs will last, because it looked to me like they cut into the tubing. Conceptually, it seems like an okay fix. If you did remove the bottom lug, you could still save the top head lug by just removing the head tube from it. What you will find, probably, is that the mitering was not that good. And that will be a conundrum, because there isn't much you can do about it.

Multiple welders have said that TIG wouldn't work because of the brazing filler

I wouldn't try to weld that, because the filler metal(brass/silver) will mix with the weld puddle and make a mess. If it were mine, I would grind the cracked area back to clean metal and lay a brass fillet over the whole acute angle of the lug. The fillet could be blended into the lug and make a nice looking repair after paint.

Here is the thread in C&V where the person ground back the lug. https://www.bikeforums.net/classic-v...urrection.html
I have no issue with that, but it seems to me that avoiding much reduction in the tube wall is key to long term life of the frame. The thing I liked was that he ground back to where he found filler.

One other issue with your frame might be that there is no filler all the way around, just at the shorelines. Do you then keep grinding, or hope the lug holds?

https://cimg4.ibsrv.net/gimg/bikefor...82221aec3.jpeg
G'day, bit of an update..

Welders at work appreciate the filler consideration but figure it may be worth a blast, aside from the cleanup, it probably can't be worse right? Thought best to see more of the story so I fashioned a poor man's Dremel and poked away at whatever felt soft, result is attached.

I'm seeing if I can contact some local builders, fillet idea sounds good 🤞