Top tube dent: Drill a small hole and pull?
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Top tube dent: Drill a small hole and pull?
I've been reading up on the various methods people use to fix a dented top tube and te one I never come across seems the most obvious: Drill a small hole and pull the dent with a hook. Why not? Small holes are drilled in the top tube all the time for internal cable routing and cable guides, so it seems strength loss isn't an issue.
Any comment from the builders? You guys are certainly holders of the final word.
Thanks,
DG1
Any comment from the builders? You guys are certainly holders of the final word.
Thanks,
DG1
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The usual method is to use a block of hardwood with a hole in it the diameter of the tube.
Cut the bolok in half and wrap it around the dented area.
Now clamp the blocks & frame in a vice.
Tighten the vice a bit and twist the frame back and forth.
Tighten more, twist some more until the dent is nearly gone. then Bondo before painting.
ANOTHER method used by auto body shops is a spot welder that welds pins on the dent (rather than the old fashioned way with holes). Then a slide hammer is attached to the pins and carefully pull the dent out. Cut & grind the pins. Bondo, paint.
Cut the bolok in half and wrap it around the dented area.
Now clamp the blocks & frame in a vice.
Tighten the vice a bit and twist the frame back and forth.
Tighten more, twist some more until the dent is nearly gone. then Bondo before painting.
ANOTHER method used by auto body shops is a spot welder that welds pins on the dent (rather than the old fashioned way with holes). Then a slide hammer is attached to the pins and carefully pull the dent out. Cut & grind the pins. Bondo, paint.
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thanks DrDeltron, that was some great information. I always wondered if there was a way to pull a dent out..
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i have had great success on thinwall steel frames with using a glob of two part epoxy resin (West Epoxy). glob it IN the dent, and before it curessink the head (flatpart) of a nail into the expoxy. Let it cure overnight and in the morning grab a pair of vice grips and clamp the nail. Wiggle and pull the dent out or use a slide hammer (best) then sand the epoxy flush, repaint.
#5
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I would not recommend simply drilling a hole and pulling for a couple of reasons. First off, your comment regarding holes being drilled for cable routing, while technically this is true, those are almost always re-enforced with a braze-on. The other reason is the property of the metal. It's really thin, not like sheet metal on a car, and it's also a lot harder than the steel a car is made from. I fear that what you'll end up with is a rippled section of tubing....with a hole in it. Deltron's method is what we always used in our frame shop, if we just didn't replace the tube. Bushman's epoxy method is a new one to me, but it sounds like a great idea, and like he said "...have had great success...". Either way you choose, good luck!
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Thanks guy's; some of the most informative replies I've ever read on the forums. What about magnets? I think it's possible to put a positive pole on one side of the tube, the side with the dent on it, and negative to the other side (or am i thinking positive/positive?). once together, the two halve will try to push away from each other. Could this effect pull a dent?
DG1
DG1
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