FW: [CR]Dent Removal

(Example: Framebuilders:Dario Pegoretti)

From: "RB" <2wheelseal@earthlink.net>
To: <classicrendezvous@bikelist.org>
Subject: FW: [CR]Dent Removal
Date: Sun, 10 Jul 2005 17:06:08 -0700


Just thinking out loud here. Could you drill the head tube from the top, to get into the top tube (at an angle, small hole, using the discoloring on the inside of the head tube where the braze is for a guide for the location). Then tap the hole and thread in a fitting to connect the porta-power to? I think this would be the least damaging way to do it (head tube won't be stressed and subject to later cracking like drilling the top tube or seat tube would be). The porta-power would generate enough pressure to un-dent the tube. However I'm not sure the brazing will be stronger than the tube wall (have to ask a metallurgist on that). Upside is that you can build the pressure gradually with the porta-power, and see what happens.

I know motorcycle restorers used to use compressed air to remove dents from gas tanks.

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.

Even so, any repair that failed in the top tube will not be a catastrophic failure - Speaking as someone who has cracked and snapped plenty of [mountain bike] frames [steel and alum], the down tube should have enough integrity to stay together and keep you from crashing. If it failed, it would most likely be after you hit a big bump. Impact load would overcome the weak spot after LOTS of fatigue, and you will here a pop or ping. The frame might bend a bit upon failure if under major stress, but doubtful it would simply snap both tubes and/or fold, causing an accident.

My .02. :)

Bill Roberts Jacksonville, OR

-----Original Message----- From: classicrendezvous-bounces@bikelist.org [mailto:classicrendezvous-bounces@bikelist.org]On Behalf Of Carb7008@cs.com Sent: Saturday, July 09, 2005 1:19 PM To: dcwilson3@yahoo.com Cc: classicrendezvous@bikelist.org Subject: [CR]Dent Removal

Thanks for the concern but no need for flowers (yet). I haven't given-up on the procedure but due to busy season at work, I am unable to devote a block of time necessary. I was easily able to generate over 4,500 psig using a porta-power (hand-operated hydraulic pump). The stumbling block is the hydraulic-line / bike-frame connection. Not having a machine-shop, this connection must not only be jury-rigged, relatively safe, but it must also work. I have a couple of methods in mind, but, they are still in mind.

Jack Romans
Sacramento, CAL