“Details make perfection, and perfection is not a detail.“. -Leonardo Da Vinci
Details matter. As a body work professional, there needs to be a lot of pride taken in how well the details are done. One of these crucial details is the door gaps. They need to be consistent, flush with adjacent panels, square; as perfect as possible.
Here’s the way to determine how tight the gaps can be. The clearance needed with the fender for the doors to open is what decides how tight the gaps can be, so start there.
All the panels must first be adjusted as perfectly as possible. Then, those long aluminum spans of c-channel or flat stock have to be used to show where the panel edges need to be. Move the panel edges out, so when the c-channel is laying against the body, all the panel edges just barely touch the aluminum. See picture below.
Notice how the door and fender edges just touch the aluminum. This shows you where the body filler will be, and ensure the edges will stay thin and bare metal.
The gap can be made as tight as desired, as long as there is clearance to open, with the edges in the right spot.
This avoids getting well into the body work, and having some material build up on the edges of the panels, and then finding out the door won’t open. Discover that first!
**A side note. The gap should be the same exact size for all panels that open. This includes doors, fenders, decklid, etc. So all these panels come into play with how tight a gap can be. Don’t start at the hood, and find out you made it tighter than the door gap can be.