Any suggestions for fixing rust, short of a visit to the body shop?

Dear Car Talk

Dear Car Talk | Sep 01, 1999

Dear Tom and Ray:

My car has spots of rust. Please teach me the best way to treat it. I've
retouched it, but it continues to spread. A friend told me to sand off the rust
and then retouch it. I think that only created scratches. Next thing I was told
was to put a dab of wax over the rust. That just seemed to collect water and make
it worse. Now another guy just tells me "body shop, body shop!" The spots are
still small. Is there any way for me to fix this without taking it to the body
shop? -- Chika

RAY: Rust is tough, Chika. And it never sleeps, as they say. Truly, the best way
to fix it IS to take it to a body shop and have the spot ground down to the
metal, filled with body-filler, re-primed and then painted. But that is
expensive, and it may not be worth it on an older car or a car you don't plan to
keep for a long time.

TOM: It also may not work. The rust may eventually come back, since it's such a
sneaky little substance.

RAY: The only "home/consumer" product we've ever had any real success with is
called Extend. Extend is a white-colored, paint-like product that bonds to the
rust. And as it bonds to the rust, it turns black.

TOM: And once it turns black, it serves as a primer coat, which you can then
paint over. It's worked great on my barbecue grill over the years. I've got
125,000 rust-free burgers on the thing now.

RAY: Of course, since the primer is black, you'll need about 16 coats of touch-up
paint to even start to cover it up. So don't expect the end product to be
showroom perfect.

TOM: But if your objective is to slow the corrosion, Extend is probably your best
home remedy. Good luck, Chika.

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