Torch a 531 frame?
#26
Senior Member
Join Date: May 2003
Location: Mountain Brook. AL
Posts: 4,002
Mentioned: 14 Post(s)
Tagged: 0 Thread(s)
Quoted: 303 Post(s)
Likes: 0
Liked 136 Times
in
104 Posts
To reiterate Andrew Stewarts comment, media blasting of such as 531 should be done cautiously. 531 tubing for
bicycles was in the 0.022 to 0.045" thickness range. Bike Tech magazine in the early '80s media blasted sheet
metal of various thicknesses (basically bike tubing) and measured before and after thickness with various media
and found that sharp sand (the most aggressive) could remove upto 0.006" of thickness. Since this removal
would be assymmetric the risk to the frame could be significant. Soft media only should be used for quality
frame paint removal.
bicycles was in the 0.022 to 0.045" thickness range. Bike Tech magazine in the early '80s media blasted sheet
metal of various thicknesses (basically bike tubing) and measured before and after thickness with various media
and found that sharp sand (the most aggressive) could remove upto 0.006" of thickness. Since this removal
would be assymmetric the risk to the frame could be significant. Soft media only should be used for quality
frame paint removal.
#27
Senior Member
Join Date: Jul 2015
Location: NW Oregon
Posts: 2,975
Bikes: !982 Trek 930R Custom, Diamondback ascent with SERIOUS updates, Fuji Team Pro CF and a '09 Comencal Meta 5.5
Mentioned: 15 Post(s)
Tagged: 1 Thread(s)
Quoted: 1299 Post(s)
Liked 739 Times
in
534 Posts
MEDIA blast only, IMO... if the tubes are double-butted, that means the CENTRAL sections of the tubes are THINNER... sand WILL remove material, and the results can hurt!
#28
Senior Member
Join Date: Jul 2015
Location: NW Oregon
Posts: 2,975
Bikes: !982 Trek 930R Custom, Diamondback ascent with SERIOUS updates, Fuji Team Pro CF and a '09 Comencal Meta 5.5
Mentioned: 15 Post(s)
Tagged: 1 Thread(s)
Quoted: 1299 Post(s)
Liked 739 Times
in
534 Posts
The metal Gods have spoken....
if you overheat high carbon steel, it changes the crystaline structure of that steel... the result is BRITTLNESS, and you must then reverse the process slightly by ANNEALING the steel... brittle is NOT a good thing, and the frame may very well CRACK... frames flex, flexing brittle steel makes cracks. Cracks lead to pain, both physical and emotional.
if you overheat high carbon steel, it changes the crystaline structure of that steel... the result is BRITTLNESS, and you must then reverse the process slightly by ANNEALING the steel... brittle is NOT a good thing, and the frame may very well CRACK... frames flex, flexing brittle steel makes cracks. Cracks lead to pain, both physical and emotional.
Thread
Thread Starter
Forum
Replies
Last Post
darker
Classic and Vintage Bicycles: Whats it Worth? Appraisals.
3
06-20-17 10:09 AM