Lumpy Sill Repair

[cobolman]

Project Marty is an early Mk 1 car (1960) and as such has a simple sill panel without flutes.

But my sill has lumps and bumps in it that won't have been part of the original build and I'm trying to understand how it might have happened. Things I've considered:

1. It's been hit by something. But that wouldn't explain why it has lumps (coming outward), rather than bumps (going inwards)
2. There's foam inside the sill and someone welded a patch onto the sill, the foam expanded, and created the lumps. (But I'm pretty sure that the foam filler that was put in sills was done t later cars and my car was not part of that batch - it's too early.
3. It's rusted and blown out. But there's no 'crunchiness' that one might normally associate with rust - and which the blasting would've removed as well

Any thoughts on how these lumps and bumps might've come about?

Lumpy Sill.jpg

[mab01uk]

Does the inner sill and internal floor in that area show any evidence that someone has 'DIY' tried to bash out a crease/dent in the outer sill/floor from inside where it is not double skinned box section..but not very skillfully? In the photo it does look like there is some evidence of a crease along the top of the bumpy bit.

[cobolman]

Does the inner sill and internal floor in that area show any evidence that someone has 'DIY' tried to bash out a crease/dent in the outer sill/floor from inside where it is not double skinned box section..but not very skillfully? In the photo it does look like there is some evidence of a crease along the top of the bumpy bit.

That's a very good point! I hadn't noticed that. It's certainly a compelling idea.