Mounting onboard charger on aluminum boat??

[unable to retrieve full-text content]

Instructions say to drill holes and use bolts and nuts which I can do as I am mounting the charger up inside the center console so it is easy to feed cables to battery box.

The instructions state to either mount on wood or plastic to isolate the charger. Ok, I could put it on plastic or wood but the instructions say to even keep the bolts from touching the aluminum. How in the heck is that even possible to do? What am I missing????

Mounting onboard charger on aluminum boat??