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Darkness95m3
12-07-2009, 10:08 AM
Rubber Undercoating! Not good if your car is NOT brand new. The only time you should use this crap if the metal is clean and no rust and it's dry. Spraying this stuff traps all the moisture and speeds up the rust process. I bought a 91 318Is and somebody sprayed rubber undercoating over the gas tank. Lucky for me I got to it in time before it got any worse.

Ceeker
12-07-2009, 10:29 AM
The chemical process of rust is not moisture itself. There also needs to be oxygen combined to make it happen. otherwise rain would make metals rust that are coated.
rust in most cases in our climate occurs from lots of moisture and salt. Salt from winter driving by itself is not corrosive. Salt mixed with water is. mixed with very wet cold temperatures makes this stick to the surface of metal. Corrosion is the culprit to rust. If you spray rubberized undercoating on a moist area it won't stand a chance to stick for any length of time anyway. Will the area rust futher? maybe, maybe not. Afterall, no oxygen could be present. once rust starts, you can only slow the process, and not "stop" it unless to remove it completely. I've had really rusted areas I kept under control for several years just by coating the crap out of it with grease and Crown- Moisture couldn't get in and neither could oxygen. Did it get marginally worse, not from what I observed. Did it get better? nope. the undercoating will just peel anyway after a while and the rust shows up again. Something is better then nothing. If it's really really bad rust...what's the point anyway? :-)

Darkness95m3
12-07-2009, 03:21 PM
I don't know where you get your facts from and how long you have been driving. However with 28 years of driving and some 38 vehicle that I had under my name. The bottom line is, do not use undercoating it does and it will make things rust a lot faster.

Gamite
12-07-2009, 03:33 PM
Ceeker is correct, Rust is the oxidation of metal, which requires a combination of oxygen and moisture.

However, Darkness, u are correct too, if you spray the underside of a car that has not been cleaned you could in fact be trapping the oxygen and moisture under the spray.

Jon@Bimmersport
12-07-2009, 03:40 PM
Ceeker is correct, Rust is the oxidation of metal, which requires a combination of oxygen and moisture.

However, Darkness, u are correct too, if you spray the underside of a car that has not been cleaned you could in fact be trapping the oxygen and moisture under the spray.

Julian Lai the science guy....

Gamite
12-07-2009, 03:44 PM
Julian Lai the science guy....

Julian Lai the wikipedia guy. And I'm willing to admit it too!! :)

Ceeker
12-07-2009, 11:43 PM
I don't know where you get your facts from and how long you have been driving. However with 28 years of driving and some 38 vehicle that I had under my name. The bottom line is, do not use undercoating it does and it will make things rust a lot faster.

You should try re-reading what I wrote clearly before jumping to conclusions. :-)

Darkness95m3
12-08-2009, 09:13 AM
You should try re-reading what I wrote clearly before jumping to conclusions. :-)

Yes, you should!

As I stated before;

" The only time you should use this crap if the metal is clean and no rust and it's dry. Spraying this stuff traps all the moisture and speeds up the rust process."

magnus
12-08-2009, 01:45 PM
water = H2O...i swear that water had oxygen.
lol

Dark is right on this.
Its the same if you paint over a rust spot....it will just get worst underneath!

Bullet Ride
12-08-2009, 02:02 PM
Its the same if you paint over a rust spot....it will just get worst underneath!

For sure. Painting over rust isn't going to make it magically dissapear (unfortunately *mumble*). A good coating of paint over rust will slow down the process however.

This will be the first winter that I have with my car so I hit it with the asphalt undercoating about a month ago. I brought it into a heated garage a couple days ahead of time to make sure it was dry, cleaned up the underside and gave it a nice coating. We'll see how it looks in the spring *smoke*

blk3
12-08-2009, 02:05 PM
nothing says lovin for a car than a good dose of rustproofing

Blades
12-08-2009, 03:37 PM
Ceeker is correct, Rust is the oxidation of metal, which requires a combination of oxygen and moisture.

However, Darkness, u are correct too, if you spray the underside of a car that has not been cleaned you could in fact be trapping the oxygen and moisture under the spray.

I think there is more to it then that. The acid in the water plays a great role, hence why cars rust faster in Ontario then Alberta for example. We have more acid in our rain.

Also salt on the roads which from my understanding they switched from salt to something else.

Ceeker
12-08-2009, 06:48 PM
Yes, you should!

As I stated before;

" The only time you should use this crap if the metal is clean and no rust and it's dry. Spraying this stuff traps all the moisture and speeds up the rust process."

whatever....

318compact
12-12-2009, 12:36 AM
I think there is more to it then that. The acid in the water plays a great role, hence why cars rust faster in Ontario then Alberta for example. We have more acid in our rain.

Also salt on the roads which from my understanding they switched from salt to something else.

Alberta cars are cleaner because they use a lot less salt than in Ontario. They use more sand and also there is less need for deicing since Alberta just has a dryer climate.
I'm not sure if the deicing fluid they now use in the GTA is any better for cars than salt, however it is not very effective once there is ice and snow on the road - they use it mostly to coat the roads before a snowfall or icing situation.

aaron320i
12-12-2009, 06:34 PM
Btw salty water from winter driving is only corrosive above 5degrees. Otherwise as long as the car is outside in the cold and rinsed down on the warmer days your car will last longer rust free, for those who are willing to disagree try it for your self. For instance I'll drive my car through all the salty water and crap and park in a heated garage every night and poof rust. I then cleaned the rust off with a little gas and left in ouside and rinsed the car on the warmer days and since not any sort of rust but before when stored salty and in a heated enviorment rusted nightly.

Blades
12-12-2009, 09:23 PM
Alberta cars are cleaner because they use a lot less salt than in Ontario. They use more sand and also there is less need for deicing since Alberta just has a dryer climate.
I'm not sure if the deicing fluid they now use in the GTA is any better for cars than salt, however it is not very effective once there is ice and snow on the road - they use it mostly to coat the roads before a snowfall or icing situation.

yes that is true and plays a roll but look up acid the in rain (Albert vs. Ontario)