Car rusted beyond repair?

[fullpampers]

I have a 2003 Hyundai Accent.

This summer I had as a project to de-rust the car. I already started since one of the fenders  had a rust hole, and the bottom of the doors were in bad shape. The fenders are done and I just have to paint the door bottoms.

My plan was to finish the few rust spots on the back of the car and clean/spray under the car to stop the rust. But as I was working on the car this weekend I had a look under and it's in pretty bad shape... My initial plan was to wire wheel everywhere and spray undercoating. but the rust is in a lot of tight or difficult to access areas. I just don't know if it's worth doing...

Another option would be to jack the car and pressure wash under, before spraying an undercoat, to hopefully slow down the rust.

I'm asking here since most people here would to everything possible to keep the car instead of just changing it. Is this a pointless project? I live in Montreal, Quebec so our roads are pretty salty during winters. I don't mind doing the job, but from how it looks under the car, I'm just not sure if I wouldn't be wasting time and money...

Other than that I don't have any problems with the car aside from the front stabilizer arms that are clunky (which I might fix or not, depending on the rust situation...)

What do you guys think? let the car rot and change it when it's done? Roll up my sleeves and just do it? Are there any other options I'm not considering?

Thanks
J-S

[phred]

Undercoating will not prevent or stop the rust already there.  In fact, by acting as a seal, it will make the rusting worse.

If you can't wirebrush the rust, can you spray on a solution such as Evapo-Rust?  You will then need to spray on a primer followed by a compatible finish coat.  Every Fall spray the entire underside with cheap oil (not crankcase drained oil -- which is acidic).

To completely be sure of stopping the rust you would have to strip the car down to a bare metal shell, and then get it chemically dipped before repainting

[fullpampers]

From what I know Evapo rust works only if the metal is submerged (unless I'm wrong).

But I could spray with cans of rust converter. I hadn't thought of that.

So pressure wash the crap out of under the car, spray with rust converter, spray some paint maybe? then oil under the car every fall.

Would that slow down the rust?

[lthenderson]

In fact, by acting as a seal, it will make the rusting worse.

Actually if you completely seal it, the rust would stop because it needs oxygen to continue. However, the likelihood of making a complete seal and getting stuff to bond to rust is slim.

[BDWW]

A rust converter would probably be the only economical way to go. It's essentially a primer that chemically bonds to iron oxide and prevents spread.

[paddedhat]

Wire brush first. I use a cup style wire wheel in a 4" grinder. It is a rust eating machine. You need a full face mask when doing this, or you will spend half your time digging crap out of your eyes.  Next coat everything in rust converter. Final step, coat everything in "Fluid Film". It's available from Amazon, and it is damn close to magic in a can, when it comes to preventing future rust damage. My son runs a shop that does heavy equipment repair, that use shit-loads of the stuff to protect their equipment. It's nasty to apply, and makes the car smell like a wet dog for a while, but if applied regularly it will keep new vehicles from rotting, and stop next year's rot on older cars, even where you live.

[Jeremy E.]

Certainly not rusted beyond repair... I've worked on a car that was so rusted it required me to put new rear quarter panels on it, do an immense amount of welding, especially around the rear windshield, sand for weeks, etc. That was a LOT of work.

[sokoloff]

I've also had excellent results with POR-15 ("paint over rust"). The original POR15 black isn't UV stabilized, so you can't use that on the topside of the car, but for the undercarriage, it's unbelievable how well it works.

Tip: Use disposable supplies and applicators, and be careful of getting it on your skin.
Pro Tip: Be particularly careful of getting it on your hands and deciding to stop for a quick pee.

[fullpampers]

Thanks everyone! I just wanted to make sur it wasn't pointless to do. I'll get to it as soon as possible!

[ubermich]

What kind of car and how severe is the rust at critical areas like suspension mounts and sub frame mounts?