Welding air rails of headers

sorry to be vague..

but I had read in the past, something about welding the Air Rails.. and that at some point dealers were doing this as warranty work..?

something about a nocking/ticking sound at cold start for 20seconds.. and then would go away as some heat built up in the header.. and that it had to do with the rails..?

in the past I was doing some research about symptoms/signs of header failure.. and this about the Air Rails was one of them.. in addition to changes in exhaust note from cracked tubing and fiberlgass shards in the engine bay from the insulation inside shields..

so what was this about to weld the air rails..?