Unless you are very fortunate to locate an early Holden with no rust, this will
be one of the first and most importent jobs you will encounter. Good bodies, these days, usually consist of a basically sound
body, which will most probably require to sills and floor - they rarely rust elsewhere, and if they are are usually regarded
as a sub-standard example.
Rust repairs are expensive if sub-letted to a panel shop, but can be handled
by yourself if you have basic welding knowledge, though planning and a lot of care used. Careful measurement, fitment, and
slow progression will ensure a good repair and successful start to the rest of the project.
Sills are by far the hardest repair, and the most common as they are in three
section, each one being separate, though an inner and mid-sill section is now available. The sills, especially in sedans,
carry all the body strength and incorrectly fitted the doors will not fit, and the body rendered useless.
By far the easiest way to fit sills that I have used is with the doors and subframes
fitted, the body supported beneath the rear spring hanger, front crossmember beneath the subframes, varying height until an
even gap around the door, and good fitment is achieved. When the sills are fitted in this position, body alignment is usually
quite good and fitting of the doors goes well. Tacking in the sills is all that is rquired for checking of the body measurements,
which can be found in the workshop manual. It will also be noticed that from the second floor crossmember the sills (inner
and outer) taper inwards, which the replacements do not. So for a good fit the sills must be bent in the original manner.
Front corner posts are a major section of strength and usually are the first
to rust, they tie the "A" pillar to the sills, and support the majority of weight of the vehicle. These are easy to replace
and reproduction parts fit well. Floor sections are likewise easy to replace, and being made of flat section are easily bent
to fit up to replacement sill and crossmembers.
It must always be remembered that rust repairs will form the first major repair
work and that the strength of the finished product will rely on the care and thought exercised in this initial stage. It is
a good time to work in some extra drain holes to allow water to escape and combat rust as the original drains blocked easily
and helped make Holdens known as "rust buckets" as far back as 1953.
As all body repairs should be fully set and welded, as extra strength will be
gained from this, also it is needed for roadworthiness (brazing is also accepted but does not give equal strength to welding)
and to provide similar strength to the original spot welds, it is also advisable that floor repairs where overlapped should
be welded both top and bottom to fully seal the repair and provide improved strength.