View of the ‘lever arrangement’; a fulcrum, stick, and bucket with two jugs of antifreeze to hold the roof reinforcing metal piece while the silver epoxy cures for five hours.
At 75 deg F, the curing time is about 5 hours, and neither of us wanted to hold the plate that long. Also note the trouble light wedged between the headliner and roof, both for lighting and adding a bit of heat.
This metal piece reinforces the roof metal for an oversize whip on a standard NMO through-hole mount.
Not shown is a blanket on the roof to help keep heat trapped to assist the epoxy cure.