Goin to slide 20ft gate into yard entrance. Plan to make gate as diagram below wit 50mm box frame with angle welded to box to bolt space board into as quiet windy location. Planning to have it Galv dipped and wondering will galv go in between where angle is tacked to box or will I have rust weepin out n time to come? Space Sheeting is to add privacy to yard also. Is there a better alternative to box angle arrangement or indeed to space boarding?