Rust treatment

CiniO

I have few places on car (mostly underbody) where I would like to clear rust and secure so it would last few years.

I'm not talking about whole underbody rust treatement, but just few spots.

Most what I'm interested in, is what to use?

Is clearing rust with sandpaper or wirebrush a good idea?
Or is it better to use some formula or something to clear it?

Then, when it's cleared up to the metal, what's the best to protect it? Just a prime paint and regular metal paint, or something else?

Any ideas are greatly appreciated...
Especially in relation to what products should I buy, as I'll be shopping tomorrow and hoping to do some work on the weekend.

CJhaughey

I have found that sanding gets more off than wirebrushing which tends to just polish the hard rust.
A 4.5" angle grinder with a flap disc of 120 grit works well and isn't too harsh.

I follow that up with some rust killer which has various names like Kurust etc, once that has dried on it will convert the rust to a hard black oxide layer and I paint over that with a Zinc rich paint and then either paint or spray some underseal on that to stop it chipping away.
Its time consuming but if you want to stop the rust for a longer time you have to do it like that.
Sanding and Zinc primer will work but not as effectively.

JohnBoy26

Apply Bilt hamber rust remover gel put cling film over it and leave overnight, repeat the process until the rust is completely removed. When rust is removed and the gel is washed off and the area dried apply a few coats of bilt hamber electrox followed by a cavity wax over that for the best results.

If the rust is very heavy you can sand it down a bit first before applying the gel.

Hal1

I got an advisory for rust on my nct, so had to get new metal welded on both wheel arches and the corners of each door sil. I had previously treated the area but didn't last 12 months til the tester's spotted it. Yeah 3 testers proding with screwdrivers like it was nothing .

JohnBoy26

Hal1 wrote: »

I got an advisory for rust on my nct, so had to get new metal welded on both wheel arches and the corners of each door sil. I had previously treated the area but didn't last 12 months til the tester's spotted it. Yeah 3 testers proding with screwdrivers like it was nothing .

Areas like this rust from the inside out and it's very difficult to treat without getting directly to the rust on the inside.

Hal1

Oh yeah a section on each wheel arch was rusted right through. On the bottom of the door sil where the seam is had split, allowing water to ingress into the inner areas.
It's had the rust cut out and been welded with new metal. Treated with krust and zinc 182 primer.

The place I used have seen it many times and deal with the likes on a regular basis. Plenty of classic cars in the place too.

JohnBoy26

Hal1 wrote: »

Oh yeah a section on each wheel arch was rusted right through. On the bottom of the door sil where the seam is had split, allowing water to ingress into the inner areas.
It's had the rust cut out and been welded with new metal. Treated with krust and zinc 182 primer.

The place I used have seen it many times and deal with the likes on a regular basis. Plenty of classic cars in the place too.

That should last a long, long time. It's the only way to repair that kind of rust. The usual quick filler jobs only last a few months or so.