Body guys, has anyone done this?

[7E-Bodies]

Ok all. This one has me wondering. I've seen it on a few YouTube videos by guys that really get into detail, yet don't say what they've done in mudding the door gaps prior to blocking body lines. It's getting down to that with my project. Can anyone go into detail on this? This pic is a screenshot of my tv during a YouTube video.

[7E-Bodies]

Namely, I'm wanting to know how they do it and how the hell they'd dig it out when done. 
 

[cuda hunter]

It's just bondo so probably just cut through it and sand it round to match the door contour.
Slick idea really.  I bet that makes the car really flow together and almost blend that door seam. 

[Blowout]

I did this on my Chevelle after I welded up gaps that were too wide.  But once I aligned the doors as best as I could, I ran coats like your picture above and block sanded the two panels together.  Very messy, and a very long process but it sure did help get the panels to all flow together and it turned out really well.  As stated above, I would cut the body filler, and then use a paint stick with sandpaper and sand down the gaps so that the width of the gap was consistent all the way around the door.  The stick with sandpaper worked for me as for as the perfect gap width, yours might be different. 

Once thing to watch for, if you have a low spot between the two panels, the body filler will make a thicker edge on your door for example and will look oblivious that the body filler is thicker there.  So getting your panels right before is key to that.  That was the hardest part I thought.

[Burdar]

The guy that painted my car does it this way.  All the gaps are tightened up beforehand and all door/trunk weatherstrips are installed.  He muds right over the gaps and sands across them.  Once the sanding is done, he cuts through the filler and cleans up the edges.

[7E-Bodies]

Seeing some good advice here. Thanks guys. I've already mig welded my door gaps to a dead nuts 3/16" (something I'm actually good at) and aligned body panels laser straight while double checking meticulously with a 3' straight edge, so I'll be doing the body filler on the gaps now that I've heard some testimony on this. I may forego the 52# door weights suggested by @Cuda Cody (making up for window/hardware weight in doors) during this phase as I don't want that kind of weight on the unibody while on rotisserie. I'll include a link for one of a couple channels I watch. I think this guy is the best. I've watched him on 3 E bodies. He does the gap bondo as well, yet never quite explains that part.
https://youtu.be/jfZLriCoNyM?si=o8fJJL6_r3GqM0FD
PS: I did use Cody's 52# door weight idea during initial panel alignment and quarter panel replacements. I really like that.

[RUNCHARGER]

Obviously some pros do it. Myself I wouldn't build it up with bondo. What I've done is mig a bit of weld in there and shape it with a flat grinder and fine tune with a file. If you're going to try it I would use All-metal, hopefully it will resist chipping. I guess if the car doesn't get driven it wouldn't matter.

[jimynick]

I, too, have seen the process and while it'll work well on the majority of the panels surface, the fly in the ointment is mudding to cure door gaps. It's misery just waiting to happen, because there's nothing to support the edge mud and it'll chip easily should anything hard contact it. I'd build up and correct in steel the gaps. Then you can hammer, tweak and/or grind on them to achieve the result you're looking for with a durable edge. Just my 

[71chally]

I wouldn't use filler on door edges. Use filler rod, and don't weld on the edge. Generally you cut the door and spread the factory rolled edge outward.  My understanding of the purpose of this is to lock a door flat, without a latch in it...

[7E-Bodies]

Not at all suggesting using mud on door edges. I'd never do that.