On all bolts we used blue loctite.
Fitting solar panels to roof rack.
To secure the solar panels to the unistrut crossbars we used 3 8 bolts external tooth lock washers and nylon unistrut cone nuts.
In order to fit thicker 3 8 bolts into the 1 4 holes on the hightec solar panel we drilled out the hole with a 3 8 bit.
I live the van life full time out.
The second option is called a comp out where your installer will remove the tiles where you intend to put solar then lay down composite shingle to install the array.
Both cone connector sizes are available at big box hardware stores.