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Torch a 531 frame?

Old 05-22-17, 07:15 AM
  #26  
sch
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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.
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Old 05-22-17, 01:42 PM
  #27  
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Originally Posted by davidad
Keep it below 1200 degrees. Better yet if there is a machine shop in your area they may have a sand blasting booth for this job.
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!
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Old 05-22-17, 01:49 PM
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Originally Posted by chorlton
Response from Reynolds... Sorry if it is a bit small.

[/FONT][/COLOR]
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.
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Old 05-23-17, 07:30 AM
  #29  
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Originally Posted by davidad
Keep it below 1200 degrees. Better yet if there is a machine shop in your area they may have a sand blasting booth for this job.
Don't get any way near 1200, I have seen a lot of carbon steel twisted up in the 800 degree range!
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Old 05-23-17, 01:20 PM
  #30  
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Haven't changed my mind. Still reccomend chemical stripping. A 30 year old 531 frame deserves time and TLC.
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Old 05-24-17, 07:21 AM
  #31  
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Originally Posted by FBOATSB
Haven't changed my mind. Still reccomend chemical stripping. A 30 year old 531 frame deserves time and TLC.
I guess that sums it up. I have changed my mind and I will be using Chemicals.
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