So wait.... are you saying you don’t want to use epoxy?
It's not completely clear I think, have to read the comments again.
Sorry, not saying you must do whatever either way, just stating that nobody I've seen uses welding. The epoxy is quicker and easier to shape - and easier to remove - when playing port engineer on an intake or cylinder heads. I'm quite sure no one here will object to any method you chose to achieve any results you desire. "You pays your money, you gets to take your choices". Share the results and we'll get a cup of something, sit around our warm LED displays and chat about it.