To cover the defects I guess. Whatever was on it has hardened and is falling off in chunks revealing a nice skin of rust underneath. Sadly I have discovered rusty gash in the middle of one of the main chassis members, next door to a plate that seems to have been put on previosly. I guess it will now need another plate for the MOT. Worse than that, the idontknowhatyoucallit, one of those minor chassis crosspieces under the floor to the rear of the seats I guess, has corroded badly.
The question is, are those cross pieces important structurally for the MOT, or can one get away with it so long as things are holding together ?
With the MOT only a couple of months away I am only just tackling the footwell to make the holes vanish with filler, and glass fibre before I put the shiny aluminium interior fabrications I made, back in.