John,
Bondo is quite commonly used for dent repair on painted frames, and I've never seen bondo come out of a dent. One would have to do something completely wrong to have that happen. For most dents on frame tubes a proper rounding of the area with frame blocks and then bondo is usually the best way. Lead solder is OK too, but really unneccessary. If the repair area is to be plated, then brass is the best choice, and even then may show a little, even if copper buffed before the chrome process; but then again some dents do actually disappear. This is delicate work and experience is neccessary; have a really experienced professional take on that job. Lead solder is too soft to be plated over as a rule because of the buffing process; at least as far as bike frames go. But by the same token, I'm sure someone has done it somewhere, but I've never seen it. Have seen lead solder used on old Schwinns around the fillet brazed joints to smooth them up.
You can be "not fond of bondo" on your classic car; but your classic car is not made of thin wall steel tubeing. Bondo works fine and is the choice of every top professional I know.
Brian Baylis La Mesa, CA Not fond of Bondo on sandwhiches; but like it on bike frames when it is the best choice for the situation.
RB wrote:
> It seems to me though, that maybe just filling the dents with braze or other
> metal might be the ticket. You can still re-chrome that. Again, you'd have
> to ask a metallurgist whether this would weaken the tube. You're talking a
> custom drawn piece of steel here, with a very thin wall. If you were just
> painting it (not chroming it), and you were going to keep the bike (it would
> not be right to sell it after), then maybe just (ack!) Bondo, to insure the
> tube would not be damaged.
I'm not a big fan of Bondo. After you've spent mucho $$$ repainting after you repair the dent, the last thing you want to happen is have the Bondo fall out. Which happens all too often.
I've found the best stuff to fill dents is lead solder. It has a very low melting point, well below that of even silver solder, files easily, and doesn't come out.
--
John (john@os2.dhs.org)
Appleton WI USA