Re: [CR]Cutouts in lugs help monitor the flow of the brazing metal

(Example: Production Builders:Tonard)

Date: Mon, 02 Oct 2006 22:40:43 -0400
To: <classicrendezvous@bikelist.org>
From: "John Betmanis" <johnb@oxford.net>
Subject: Re: [CR]Cutouts in lugs help monitor the flow of the brazing metal
In-Reply-To: <005501c6e67d$d0c06cd0$76f0d045@ts>


At 07:52 PM 10/2/06 -0400, Tom Sanders wrote:
>Someone recently wrote the above line in a post...just how does the cut out
>do this? If it fills up with brazing metal, it seems like the builder would
>be highly aggravated...it would have to be cleaned out.

Not a framebuilder, but I've done lots of silver soldering. The clearance between the tube and lug and the joint itself is filled with flux. As you heat the joint, the flux melts and becomes active. Then, as the joint reaches the correct temperature you apply the rod or solder wire at the edge of the lug and it gets sucked in by capillary action. You'll see it flow around the cutout, following the heat. It won't fill the cutout unless you use way too much braze.

John Betmanis
Woodstock, Ontario
Canada