On several variables. What material the frame is made of, the nature of the damage, etc.
I only have experience repairing steel frames, though I have seen titanium, aluminum, and carbon frames repaired(saw an Airborne Lucky Strike bottom bracket welded back together on Sunday). There are a few guys around that specialize in this type of work. Franklin Frame is one(www.franklinframe.com). It would likely be beneficial to contact someone like that to get advice(it is what I do for the really tricky stuff). On that note, I was given an ancient Falcon tonight with a snapped HT/DT lug. I will be restoring it over the next couple of weeks.
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