View Single Post
Old 01-17-20, 10:18 AM
  #17  
Andrew R Stewart 
Senior Member
 
Andrew R Stewart's Avatar
 
Join Date: Feb 2012
Location: Rochester, NY
Posts: 18,123

Bikes: Stewart S&S coupled sport tourer, Stewart Sunday light, Stewart Commuting, Stewart Touring, Co Motion Tandem, Stewart 3-Spd, Stewart Track, Fuji Finest, Mongoose Tomac ATB, GT Bravado ATB, JCP Folder, Stewart 650B ATB

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 4224 Post(s)
Liked 3,917 Times in 2,336 Posts
Tacking and/or starting the full brazing along the tube/frame centerlines is generally thought to reduce the heat distortions that can lead to a twisted frame. By applying the heat at the center line and then trapping the tube together with a tack or the beginning of a full brazing traps/keys the tubes with less side ways uneven heat expansion (distortion). Once the centerlines are linked then working down and away from the centerline, a bit on one side then the other side, is the attempt to reduce the distortions and trying to be consistent WRT the heat applied on the tube sides. Andy
__________________
AndrewRStewart
Andrew R Stewart is offline