I finally got my 10 year old HD 1500 watt heater element out of my mash tun. I am replacing it with a SS 4500 watt element. The 1 inch welded coupler is in very rough shape. I can't even screw in the new element. How should I clean it? I have BKF, ss scrubby pads. When I do get it clean, should I use plumbers tape? I have keg lube too if that might help. I knew this would be a challenge though.