bighatnohorse wrote:
In the event that you cannot find metal substructure I would submit for your consideration using well nuts.
They are inexpensive and you can fail-test them in your garage/work shop by installing them in 1/8-inch luan and attempting to pull them out.
They work.
I tried well nuts and they failed to hold my solar brackets to the degree I wanted.
I chose to use rivnuts (threadserts is another name) and specifically this
rivnut kit.
Mine were inserted through the rubber roofing and luan into the hole I drilled in the roof's aluminum tubing. This has worked well for about 15 years.
