i got to weld up a 7 foot gate frame out of 1 inch square tubing, weight is a critical factor as the only support i have is a 4x4 wood post in 2 feet of concrete and due to the property boundries, and the way the gate works, i cannot install a brace on the post, i can get 14, 16 and 18 gauge tubing, i will be gas welding it as my arc welder burns too hot [ isnt 18 gauge about like sheetmetal?] can i go with 16 gauge and be ok, just how thick in inch fractions are these gauges, from here its a 140 mile trip to pick up the tubing,and im buying 140 feet of it , so im trying to plan things out first as well as the difference in price, [ its for a little old lady i got "volenteered" to help out ]