Brian mentions the use of a "rosebud" tip for doing unbrazing - it's a way of getting a very large area of flame. Now desperate times (and thin wallets sometimes call for desperate measures. I have done a weak copy of a rosebud (hold your noses hear) by just using the cutting torch with a rich (reducing) flame and keeping my hand far from the oxygen feed for cutting. I remember cleaning out one lug this way, years ago.
harvey (haven't yet built a whole frame, but talk the talk from doing bunches of repairs) sachs
At 08:57 5/27/2001 -0700, Brian Baylis wrote:
>Dave,
>
>Unbrazing the old tubes is the accepted method. I can't imagine how one
>could get a clean enough interior to get a good fit by grinding unless
>one takes out part of the intersecting tube also. It then becomes
>obvious there has been a repair.
>
>There are several tricks to unbrazing tubes that were brazed with brass.
>Can't go into it all here, but the more one knows the better. Probably
>the most difficult tube replacement are older Cinellis that have the
>trhee holes drilled in the lug, are filed thin, and also have a lug that
>was welded down the center. I've done it several times with perfect
>success, but it is VERY touchy. Once the tube is out one can reshape the
>lug edge as neccessary to make sure no evedence of repair is left
>behind. Then, it is imperative to rebraze the new tube(s) with Easy flo
>45 silver brazing alloy. Did a repair like this for Chuck Schmidt a
>while back and just finished doing one for another listmember not long
>ago. There's no way to tell that the frame was repaired. Retubing a
>frame that has been silver brazed is a piece of cake in comparisson to
>brass brazed frames. That's just another plus to add to the list of
>reasons to silver braze frames.
>
>Regarding reusing lugs, never tried it myself. Don't see the point in it
>really. Personally, I find it is easier to make whatever lug pattern one
>wants using various methods of modifying existing lugs. Of course, since
>I have a box full of unusual lugs, I'm never Jonesing for lugs to work
>with. I suppose if one was desperite and had no other options, what the
>heck; but the concept of reusing lugs doesn't sit well with me
>personally. I would avoid reusing investment cast lugs that were brass
>brazed, especially Henry James lugs; I'm certain that's not a good idea.
>One, you can get those lugs (but why?) any time.
>
>Brian Baylis
>La Mesa, CA
> >
> > I have so far only used heatless means (die grinder/Dremel, patience) to
> > remove tubes for repairs but has anyone out there successfully un-brazed
> > brass brazed lug joints?
> > David Feldman
> > ----- Original Message -----
> > From: <Philcycles@aol.com>
> > To: <Classicrendezvous@bikelist.org>
> > Sent: Sunday, May 27, 2001 7:11 AM
> > Subject: Re: [CR]Can lugs be re-used?
> >
> > >
> > > In a message dated 5/27/01 6:02:53 AM, tr4play@home.com writes:
> > >
> > > << Can a fancy lugset that is on a poor condition frameset be taken off
> > and
> > >
> > > used to build a new frameset?
> > >
> > > >>
> > >
> > > Yes but it's not as simple as "taken off." It's got to be done carefully,
> > > very carefully. For instance, older frames are frequently pinned and the
> > pins
> > > must be drilled out. Things like that. And it's easier to cut the
> frame in
> > > pieces firsts.
> > > Phil Brown