Border Edges
 

Hello their, i have a problem with border edges, the edges still don't seem weld, even if i delete the 2 quads on eatch side of the border edge, i extruded the edges again, merged them together, and again i get that border egde. In the past it always worked when i deleted the 2 quads that create this border edge, and now i can't remove the not merged edge.

Those somebody have a idea thx in advance.

Woops i posted in the animation section, my bad, i needed the modeling section.

Did you merge the vertices along the edge?

Yes, but i've removed the exhaust system, and edge extrude it closed, remodelled the exhaust in polygons, and merged it again, and now it's fixed, but i'm just wondering why 2 merged objects (combined offcourse) don't merge together, can it be something with the normals? I dident checked that out, it's to late now, i allready solved it by remodelling it.

But anyways if somebody has a answer to this mistery i would love to hear it, so i can edit it when i encounter this problem again.

Thx