Bondo panel seams.

I am having to make some panels out of sheet metal and unfortunately am going to lose a good chunk of the seam line on the rear near the gas tank. I was thinking of filling all the seams in to match and give it a cleaner look. But my concern is the combo of bondo shrinkage and panel movements. Has anyone out there done this successfully?

Probably not the way you want to do it. That being said, mine had that done when I bought it. Best I can tell it has been like this for at least 4 years before I got it. Mine cracked on both sides right behind the door but this is as big as the crack got. Dont know how long it lasted before it cracked.

The bondo will crack because of the flex in the panels. If you weld them up first, it will hold. When welding, do a small spot at a time and move around so you don't warp the panel from too much heat

Probably be easier to recreate the seam in your patch panels than weld up and puddy the whole van, unless that was your plan anyway. I've heard it is very difficult to do well.

My truck was sideswiped on the same side as the picture. None of the bondo cracked after it was hit in the area it was hit. The main flex point seems to be right behind the door, at least on mine.

Last seams I deleted, I welded the seam ground it smooth then
used dura glass filler to cover the welded area then bondo to finish
The reason I used duraglas was because it will not absorb water or
moisture and rust like bondo will

+1 on the welding...

I have to mention that I had a heck of a time with the alignment of the top and bottom panels. There would be areas that matched perfect and then there were areas that needed a lot of mud to make them match. Getting the whole side to look like one panel wasn't fun. If I had to do it over again, I would have cut the seam and realigned the panels first.

I have mine just about ready for paint, redid the cracks and the rest of the problems on the truck. I'll let you all know how long it takes to recrack. Not doing a real -correct restoration, just trying to make a nice driver.

Yeah I am still debating whether I want seams or not before I epoxy primer.
short strand fiberglass is awesome stuff for small filling.
It is strong, has some flex, and wont absorb moisture.
I will have to short strand my roof gutter as that is a nasty mess.
I am gonna get rid of the gutter all together.