dmoua68

Before and after pics...

valeoray

Did you use POR 15?

StanleyR

That's not that bad. I've seen much worse on old rwd Volvos.

LeX2K

If that's spray on tar undercoating you just made the problem worse.

bbaugher47

And this is why I refuse to buy vehicles from snowy areas.

Petet

I’ve lived in New England my entire life. If you wash your vehicle frequently in the winter it keeps the rust at bay.
I own a 05 Avalanche that gets lighter by the day. Didn’t wash it in the winter like I should have. My 08 IS was washed and garaged by the past owner and the rust is minimal.
I do agree if I’m to purchase another one I might go to a warm climate area.
If you just spray undercoating on rust it will just continue to rust under the coating. You have to treat it with chemicals to remove the rust first.

bbaugher47

I wonder if the cars sent to northern areas come pre coated to combat the rust.

AMIRZA786

Damn. I'm glad I live in California where snow is something we only see on TV...

Petet

on my avalanche there’s still some undercoating on a few spots on the frame. If I scrape it off there’s fresh new metal under it. I believe northern vehicles get special treatment. But we still get rust everywhere. I have a small bubble starting at the bottom inside door jam on the passenger door.
time to sand blast it, prime and paint before it gets worse.

Zmon

iTrader: (2)

+1. Rust needs to be removed before you put on undercoating. High chance of it flaking/cracking allowing moisture in, and you'll never notice. If it doesn't all you did was trap the rust in where it'll continue its process of eating away at the metal. You'll only notice when you're on the side of the road wondering why you have a pool of liquid coming out from under your car.

dmoua68

Oh I made sure to clean off the flakes of rust and at least touch up rusty surfaces with a metal wire brush. The easy to reach areas I cleaned up nicely with a wire wheel brush attachment on my drill. then washed with soapy water and rinsed and let dry.

Then I used rustoleum rust reformer on anything that had rust. Two coats of the reformer on the diff.

Then i layed 2 coats of rustoleum under coat on everything besides the diff itself.

dmoua68

Question. Would it be fine to spray the reformer on the driveshaft joints? The reformer wouldn't interfere with or inhibit the movement of the joint would it?

Gville350

iTrader: (10)

Tape off any part that isn't metal. I assume you're talking about the half-shafts. The rubber boots you'll want to avoid hitting with any sprays.

2013FSport

iTrader: (2)

I'm certain the rest of the car will collapse long before the diff or axles rust through....

Point - you have bigger fish to fry....

dmoua68

Why not fry the small fish too?

If I had left the undercarriage untouched who knows if it wouldve outlasted the whole car. I don't want to find out. Peace of mind.