Both cone connector sizes are available at big box hardware stores.
Install solar panel on roof rack.
Drill a slightly larger 1 32 hole than your bolt or screw size.
Learn about diy solar.
It was tough to get the bolt through several layers of washer shell gasket rack without a little wiggle room.
Installing the solar panels is done by using unistrut cone connectors 1 4 inch or 3 8 inch to attach to the slotted steel l brackets.
Have a helper press a piece of wood up from the inside of the shell to brace it against the pressure of the drill.
Screw each stanchion through the roof and into a roof rafter.
Mark the position of these holes on the solar array and then drill a hole through the board not the solar panels that is going to be big enough to run a bolt down through.
Fed up with your utility power company.
So are thousands of other diyers.
Now find a bolt that can be screwed into the attachment point on the roof rack of your car and equip it with a big fat washer.