I've scowered the web and read quite a bit on this topic. But I still have questions that I want to run past you guys.
It seems that a properly triangulated structure made of 4130 tube could sometimes benefit from a post-weld heating of the weldment to stress relieve and to reduce brittleness of the HAZ. I read several sources that stated to use a neutral flame of an oxy-acetylene torch to evenly heat to around 1100 degrees and then let it slowly air cool.
1) Could I use a MAP gas torch to heat it instead? My oxy-acetylene torch is packed up in storage and not easily accessible. And it seems that MAP gas would have less potential for hot spots anyway.
2) If there any downfall to the stress relieving process? I just want to make sure there's no way to screw it up and consequently substantially weaken the material.
Any advice would be greatly appreciated.