The sill has to be repaired in place (situ), simply
to save on time (and subsequent cost) rather than
dismantling the entire car and replacing.
My brother and I began by removing all plastic vents
by the sill and the wheel arch liner. Once Damien
had access, he began by cutting away the damaged
body work and inspecting each crack/fracture to find
weaknesses.
Preparation
At the end of each crack, holes are drilled, just
slightly larger in diameter than the crack itself,
this helps to stem the continued cracking of the
bodywork by rounding out the damage and spreading
the force across a slightly greater area... see I'm
learning fast here folks! ;)
Bodywork sanded down
Once this was done, the area around each crack was
sanded right back on both the inside and outside of
the panel. Access was actually quite easy once the
wheel arch liner and vent were removed, so this
isn't was bad as it sounds.
Once the body work around the offending area was
suitably scuffed down, Damien began rebuilding with
fibre glass matt and resin. The large piece of
bodywork that had broken away was bondend in place
from behind, to further strengthen the rebuilt
structure.
Accessing the Sill for work
Building Up FibreGlass
A slow and steady process, the damaged area is built
up layer after layer, only after the prior work has
dried completely. Once an adequate layer of
fibreglass has been built up on both the inside and
out, sanding can begin. Being unsure of the strength
of the underlying Lotus bodywork we decided against
using a DA sander and instead sanding by hand.
Although much more time consuming, this ensures that
the bodywork won't be eaten away by an overzealous
orbital sander.
Building up Bondo
After sanding back the fibreglass and creating an
adequately accurate shape, Bondo or Bodyfiller is
applied across the top of the bodywork. Once
hardened, body filler becomes a hard, but easily
sandable surface. Allowing the bodywork to be sanded
down to the final shape in gradually finer grades of
paper until a perfect shape is achieved.
Bodyfiller is allowed to set
Gradually the panel is simply worked down, layer by
layer, in exact replica to the original sill -
fascinating for me to watch being done for the first
time and unbelievably fullfilling to see things take
shape - woohoo!
Bodyfiller gradually worked to final shape