Originally Posted by
gaucho777
I think this begs the question: How much is too much rust?
I've seen oxalic acid baths do wonders here on this forum, but I'd have to think there will be significant pitting and compromised structural integrity to the frame. Hypothetically, if you were to buy this (or another) bike for the purpose of actually riding it, how would one determine if a bike/frame has been rusted too much for a restoration to be worthwhile? I know people have different aesthetic standards, but I'm mostly thinking in terms of ultimate safety/function.
Got a chuckle out of this: "It had been submerged in a canal - though I don't know why or for how long." Did the sellers g'pa leave it in the canal? Discover it in the canal? I'd love to know the full story.
I believe the thickness of the tubing walls can be determined by ultrasound or something similar. We had a corroded tank at work and they said they could scan the tank walls and determine the level of corrosion all over. We had a pinhole leak and figured the rest of the tank might be in sad shape as well or hopefully it was along a weld seam.
A bike welder might just tap the tubing in various places and listen carefully; that would work for severely compromised tubes but probably not good enough for determining rideability.