Rust is setting into my Cobalt on the underside of the hood, the pinch welds, wheels, brakes, and from what I can see (without a jack or lift) the underside is rusting for sure. It's not bad for an 7 year old car but if something's not done in the next 3 years, I will be driving a hooptie. That's what happens in Upstate NY!

Should I go to a collision shop to have the rust removed and then primer sprayed to seal it? Or should I just go straight to Krown spray and not worry about the rust spreading?

I'm also worried about Krown drilling holes. I know they say it helps the process of rust provention but no areas except the underside, hood, and the door (water leaks) are giving me trouble (to my knowledge). Once a hole is drilled, the protective cover is taken away and it makes the spot prone to rust.

What do?

 

Ive always been curious how well this stuff works, my ss has a lil rust starting underneath. nothing major though.

Repair Rusty Metal - The Rust Doctor

According to their description is chemically changes red rust that flakes to black rust that does not, black rust is supposedly inert and acts similar to aluminum.

 

The new cars coming out of the factory have the frame rails and under body holes filled with a form of foam sealant. It resembles the same stuff they use to seal house windows and doors, but, for vehicles. If they DO drill holes make sure they fill in the space with an expanding sealant foam. To prevent water and salt from getting inside.

Rust is the oxidation of metal exposed to moisture. IF it is just surface rust take it to Krown and have them spray it. If the rust is fairly deep and rotting through the metal, I would recommend a body shop removal and repair then spray with primer and sealant. Then take it to Krown and Spray. Keep in mind rust removal can get very expensive fairly quickly if a lot of metal work is performed.

Just my 2 cents.