[TowerTalk] ground radial connection question

[Richard W. Harris]

Hi,
I have an 18"x18" square copper plate.  I am going to connect copper grounding lugs to this plate along the outer perimeter.  I have drilled and tapped holes in the copper plate to hold the grounding lugs but my question is-should I simply screw/bolt the lug to the copper plate or would it be better to screw/bolt and then solder the copper lugs to the copper plate?  Also, do I need to coat with any antioxidant.  All hardware other then the copper plate (1/8" thick) and the grounding lugs is stainless.
Thanks,
Richard - KJ7CU