Africa Automotive March-April digital issue 2023

March-April issue l 2023
metal or plastic spreader, but leave a little extra on top
to sand smooth.
It takes about 30 minutes for Bondo to fully cure and
harden. After that, smooth out the extra filler you left on
top so the repair matches the contours of the rest of the
car. If you have a rust inhibitor that is safe to use with
body filler, add this now, but otherwise, you can seal your
work with a regular, high-quality primer. As with fixing
surface rust, paint and clear-coat your repaired spot, then
buff to blend it in with the rest of the car.
Penetrating Rust
After prolonged exposure, steel is converted to brittle
iron oxide and holes form.
Rust will eventually eat through your car’s metal if left
unchecked. This is penetrating rust, and it’s the cause of
everything from Swiss cheese-style holes in the fenders
to more dangerous problems with weakened frames and
suspension components.
If you live somewhere with rust-prone conditions, don’t
wait for bubbles to appear on your car’s body. Take a look
underneath the car periodically to inspect for any rough
or compromised parts that could be a safety risk on the
road if left unfixed.
As scale rust gets worse, the base metal flakes away
and leaves holes. Now you’ve got a bigger problem,
and you’ve got two options to fix it. You can completely
replace the affected part or panel (tough), or if it’s
merely a bodywork issue, you can cut the rotten parts
out and weld metal “patch panels” into place (tougher).
A reputable body shop should be able to take care of
either issue. Welds that hold on patch panels can be
smoothed out to look like they were always part of the
car by the right set of talented hands.
Car rust
lead to corrosion. Many modern car washes can blast
the underside of your car with water to get much of this
grime off.
The not-so-obvious advice is to check the drain holes
along the bottoms of doors and rocker panels, which
allow rainwater to flow out. Use a pipe cleaner to clear
these holes out, and keep the car’s nooks and crannies
dry. WD-40 can be a useful tool here as well. This
lubricant protects parts from corrosion, and its thin
nozzle can be used to reach tight underbody spots and
blast away water or corrosive grime.
As noted earlier, many vehicles have a thick coating on
the underside that chemically seals the steel against
oxidizing agents. Regular inspection and repair of the
spots that have worn bare will keep rust from advancing
and causing additional damage. If this coating is not
there, consider adding one yourself. POR-15 is one of the
more popular examples of such a rust-protective sealant,
and they even have a rubberized coating to go over it in
case you want even more protection underneath your car.
As with other rust repairs, sand off any rust that might
be sticking through and rough up the area you intend to
paint with some sandpaper, then brush or spray the new
coating on.
As long as your metal is properly sealed from the
elements and kept clean of corrosive salt and grime, you
should be able to get years of safe driving out of even
the most abused winter beater.
As tempting as it may be, you shouldn’t repair these
larger holes with body filler as you would with pits left
by scale rust.
That being said, don’t attempt to patch your car’s
frame back together. A rusted-through frame means
the structural integrity of the car is questionable, and
it should be inspected and repaired by a qualified
repair facility. You really don’t want to be in a crash in a
structurally sketchy car, so we can’t reiterate this enough:
check for rust underneath your vehicle every now and
then—before it’s too late.
How to Stop Rust from Forming
Make sure to wash behind the tires, where road gunk
accumulates and can abrade rust-resistant coatings.
Lower door corners are notoriously vulnerable to rust.
The good news is that this kind of vehicular decay
is largely preventable. The best advice is the most
obvious: Wash your car regularly to keep the body and
underside clean of the road grime, salts, and dirt that
Make sure to wash behind the tires, where road gunk accumulates and can
abrade rust-resistant coatings. Lower door corners are notoriously vulnerable to
rust. | Image: Ezra Dyer
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