Garage project season is here and my kids keep wanting to help

I'm restoring an old Honda Civic in my garage and my 8 year old keeps asking if he can come out there with me. Don't get me wrong it's cute but I need like 3 hours of uninterrupted focus to get anything done. I got him a little tool belt and some screwdrivers but mostly he just hands me stuff and asks a million questions. How do you guys balance wanting your kids involved with actually getting stuff done?