As the joints pass through this target area 42, {HEAD ~ the hot gas} 43 melts {TAIL ~ the solder mounds} 
melts
As the joints pass through this target area 42 , { HEAD ~ the hot gas } 43 melts { TAIL ~ the solder mounds }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL