P7 frame repair questions/ideas- help!

[tIB]

So after fixing up my old nickel p7 I found an issue with the frame- om the underside just under the wishbone seat stay, directly above the tyre, I found two hairline cracks in the metal. After poking around a bit I established they went through the metal tubing - not sure what has caused it but perhaps being old and not having a bolt in the underside weld hole might have lead to it getting clogged up with gunk and rusting from inside? I can't be sure though, and the issue appears to only be there after inspecting the rest of the frame.

What are my options for repair here, if any? I have access to a welder (albeit an amatuer one) who can do braze, tig or mig. My first instinct was to seal it with super glue (cowboy!) as I had to ride to work on it a few times... It's been fine so far! I suppose I could also blow out with compressed air and wd40 and them fill with some kind of composite? Or braze a piece of tubing over it as best i can? Are any of these actually good ideas? I'd like to fix it for sentimental reasons. Your ideas please.

 

[jimo746]

Can you show us a photo of the crack?
Being steel you might get away with continuing to ride it (gently) for a long while.
It might be possible to do a temporary repair which could well last a long time, fill the crack with weld, weld on a brace/gusset etc.
Ultimately though I'd think a frame tube replacement might be in order.
All depends on the severity of the crack, and if it has come from the inside out or not.

 

[tIB]

I would have been able to before I bodged it with glue and did a little brush over it with paint- nothing has come through yet after a couple of days riding. Plan was to bodge first and then see if it would open again- I suspect given where it is it is from the inside out, though I'm not sure how I'd diagnose that. I'll snap a pic of the area anyway, just to show the bodge more than anything!

 

[jimo746]

I'd be amazed if superglue fixed it for any amount of time.
But then I guess they don't call it "Super" glue for nothing...

 

[tIB]

I agree, though the method to the madness was to seal and then see if it opened up again- if it did I assume it is due to stress on that area, if not most likely corrosion from the inseid out. Of course, this theory is based entirely on what I think might be the case, as opposed to actual fact!

 

[tIB]

Link here for pic of bodge: https://flic.kr/p/H3xLvr

 

[dyna-ti]

I see where youre coming from but superglue isnt the best thing to keep the elements out, as its just too brittle.
Some shaped duct tape would do better as its waterproof outer and so sticky, nothings getting underneath.
Then just a matter of , when youve time etc to take off the tape, dress the area and reweld it. You'll lose the finish in that area but im afraid its the only option

 

[tIB]

Losing the finish in that spot isn't the end of the world- many thanks for the help

 

[02gf74]

On my mob device cant really see the crack but i doubt its cause by rust, how will water get in there plus rust causes what was once steel to flake away

What makes you sure it goes all the way rather than crack in pint?

Fixing would be to grind back tbe weld and redo it.

 

[tIB]

I could poke something through the gap so its going to need a weld- rusting through is a pure guess though, it may well just have developed a crack