painters question

You'll be close on cfm at 40 psi. The gun will use more than the head can put out. Make sure you have plenty of line for the air to cool and good filters.

Painting big panels that set up won't work great, it will do it. But, you have to keep in mind, the more the compressor runs, the more heat, which equals more moisture.

If it's humid where you live, it will be more difficult.