This may be a no brainer for you electronic types, but it came to me at supper tonight that I don't have any ground to the fuel tank, except the fuel return line.  Is an 18 gauge wire attached to the fuel sender unit sufficient for the grounding of the fuel tank.  The tank is suspended by straps, isolated by auto upholstery between panel and firewall.  Thanks in advance.  JohnD 

       Shoveling up gallons of sanding dust, try to make a cowl.  I admire you glass plane folks for your patience.  I was chuckling at the 1500 hr rotary installation until I got to the cowl