I was looking into my Hi Force 44 5/95 and it appears to be a 650F melt temp. 4/96 is apparently 475F melt temp. 63/37 tin/lead melts at 361F Bernzomatic says their propane torches burn at 3450F flame temp

I believe the internal burner rig is running out of oxygen. Some of the underwater oxy-acet rigs had air piped in on top of the o2. Would this setup be used for small gauges too?