Undercarriage protection?

When replacing the brake pads and rotating the tires on our 2000 Grand Prix, the rust on the undercarriage was quite noticeable. Not really any worse than it has been on several other vehicles, but it bothered me.
Probably pretty normal for a car 8+ years old with 65,000 miles on it.
The car is probably good for 200,000 miles and we only drive it about 8,000 miles a year so it`s possible we might own it another 10 or 15 years. :)
The deciding factor for my changing vehicles is usually when:
1. I see something I think I have to have.
2. The vehicle we are driving starts showing rust.
Emphasis on #1.
#2 is automatic. Rust shows up, it`s fixed and the vehicle is gone.
In the 8+ years, I haven`t been interested in anything else so the GP could have an extended stay. :)

To the point:
Anyone have any ideas or experience with something to use to help reduce the rust on the undercarriage?
I spray it off with both the hose and a pressure washer regularly during the warmer months. During the winter, I periodically go through a drive-thru wash that does an underbody spray. Hopefully, that helps remove some of the road salt, but.....
There might be something I can spray on that would help. I`m not looking for something to dress it up for show. I want to stop as much of the corrosion as I can.

Isn`t that what the spray on undercoating is supposed to do Charles?

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Originally Posted by blk45

Isn`t that what the spray on undercoating is supposed to do Charles?

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If you are referring to the Zeibart type of service, my personal feeling is that it wasn`t worth the cost.
I also think it has to be done when the vehicle is nearly new and the underbody is still clean and rust free.
I`m not too concerned with trying to stop body rust since I don`t really think that is possible.
What I think I would like to do is just spray a product on that would slow down the rust process.

Do you have some particular products in mind?

Hmmmm....got me there Charles. Let me rack my brain (shouldn`t take long:D) and see what I can come up with.

Use to use the Zeibart system and it didn`t hold up (due to the heavy salt on the roads) and them once a yr had it recoated with some under coated stuff i found at a auto parts store, i just can`t remember the name:hmmm:

Charles are you referring to the frame itself or the lower portion by the rocker panels.

If its the frame I take a wire brush and then give it a quick hit with Krylon or spray Rustoleum.

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Originally Posted by jaybs02

Charles are you referring to the frame itself or the lower portion by the rocker panels.

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Yes. :)
Actually, what I saw that bothered me was mostly suspension parts and springs. The GP is unibody and doesn`t have a frame as such, but it has a lot of supports under the body that hold things together. Rear axle, trailing arms, A frames in the front.
Chances are that the body will show rust long before any of those parts actually fail, but they do show some rust.

Quote:

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Originally Posted by jaybs02

If its the frame I take a wire brush and then give it a quick hit with Krylon or spray Rustoleum.

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I hesitate to use any type of abrasive to clean the areas since I might remove enough paint from the painted parts to cause more problem than my efforts would cause good.

Maybe spraying some good old STP on everything would work. :D
Heck, maybe even some motor oil or a liquid grease would stick for a few months.
The tar like stuff that is available doesn`t seem like anything I would want to use.

Sheesh if I`m worrying about this kind of stuff already, it`s going to be a looooong winter. :wall

Charles, it sounds like you and I share some of the same (probably irrational) obsessions. I dug these out of my "someday, when I have time" file:

POR-15 Rust Preventive Paint-POR-15 Inc.
Eastwood Chemical Rust Removal - Products & Supplies

Be careful with this stuff, especially the POR 15. It`ll fry your lungs unless you use a good respirator.

Happy obsessing!

Charles on April 21.1977 I bought a brand new F250 4x4.
In 1981 it had rust on the frame and axles.
I wire brushed sanded and cleaned for days before spraying with red oxide primer then Black enamel.

I still have that truck and the frame and axles still are Black with NO rust.

Paint will not stick unless it is applied to a clean surface.

Since you don`t want to use a wire brush or sand you are looking for a miracle.

The Aerosol cans of undercoating will prevent rust if you clean and apply every year.
Not a pleasant job but it works.

Their is no easy solution..
Todays power train is so reliable that in most cases it will outlast the body if you live where we do.
You can either keep it coated or trade every 10 years.

I know of no product that can just be sprayed on over the dirt and rust and have it stick.
Look at it this way it gives you and excuse to buy another vehicle every few years. :D

Thanks for all the information and suggestions.

It does seem like I am looking for a miracle product, doesn`t it? (Where are you Billy Mays?) :D

Since I have never done this to any of the many vehicles I have owned over the years, I probably am not going to do it to any of the ones I have now.

It`s probably junk, but I thought I saw a spray product before that you sprayed on rust and it would do something to it to essentially make it a primer, so that paint would stick to it. Even if it did work, I would be worried about the rust that wasn`t on the immediate surface that was "primerized". I would imagine it was only for something that had very light surface rust.

Good luck Charles. Let us know how you make out.

Charles, I`m sure that it is only surface rust, so I don`t think that there is much to concern yourself with.

For me it`s appearance, so a quick hit with some paint gives it it`s look back and offers some protection.
I generally have my wheels off least twice a year so it is easy to keep up on it.

I have experience with mar-hyde rust converting primer sealer, You just spray it on the rusty area and it turns a type of whiteish blue color but turns black as it dries. It really does work well for preventing further rusting. I first used it in the body shop I worked in and have since used it on a few trucks that I owned. I personally would spray paint over it or rubberized undercoating or something like that as it really does`nt look so good just sprayed on by itself. This product IMO really works well and is real easy for a lazy guy like me to use. I hope this has helped in some way.

I`ve taken the same approach as Black Bart on several of my vehicles and had very good luck. If the surface is painted and you are concerned about removing the paint it`s actually the perfect time to do just that. More often than not the rust doesn`t sit on top of the paint and all the paint is doing at this point is providing a cell for the rust to spread and bubble. Primer before the paint is what makes the job. I`ve done this on vehicles with 10 years of rust and as BB said it still looked very nice 5 years later.

I found this by doing a google and it states tightly bonded rust so if it is lose or flaky like nearly all rusted parts under a car are you will need to use a wire brush to make it bond.

MAR-HYDE ONE-STEP® RUST CONVERTER PRIMER SEALER, 10 OZ. AEROSOL (3509)

http://www.midwayautosupply.com/skin...s/mailicon.gif E-mail this product to a friend




Mar-Hyde® One-Step® Rust Converter Primer Sealer chemically reacts to convert rust into a hard, black primer sealer. Apply One-Step® on rusted surfaces and rust is permanently converted and ready for primer and topcoat. One-Step® Rust Converter Primer Sealer is a water-based latex containing rust modifiers, which is designed for application directly over tightly bonded rust on iron or steel. Also proven effective on new degreased or mild steel where flash-rusting has occurred. Shortly after application, the rusted surface will change form white to purple to a stable black coating. A uniform black coating indicates the complete conversion of the rust; white streaks or remaining rust indicates that an additional coat is required.


SKU:MAY-3509Inventory: Price: $11.99 (USD)

A friend of mine simply sprays the entire underside of the vehicle with chain saw oil. It`s thick enough to stick, but you need a special siphon sprayer though. It may greatly limit the spread of the rust you`re seeing. I would peruse the Eastwood site. I used this stuff called Corroless by them on my 1994 Ranger, and everything was stll pristine by the time I got rid of it.

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Originally Posted by CARTfan

A friend of mine simply sprays the entire underside of the vehicle with chain saw oil. It`s thick enough to stick, but you need a special siphon sprayer though. It may greatly limit the spread of the rust you`re seeing. I would peruse the Eastwood site. I used this stuff called Corroless by them on my 1994 Ranger, and everything was stll pristine by the time I got rid of it.

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Spraying oil will help prevent rust but it will also collect dirt making a real mess.
Their are several band-aid fixes but the only real cure is clean down to bare metal and prime with something like red oxide primer and then paint to seal and prevent future rust.

^ You`re right. It does look downright awful, but no rust. lol I dunno though... the Corroless made it through many winters on my Ranger with absolutely no sign of rust.

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Originally Posted by CharlesW

When replacing the brake pads and rotating the tires on our 2000 Grand Prix, the rust on the undercarriage was quite noticeable. Not really any worse than it has been on several other vehicles, but it bothered me.
Probably pretty normal for a car 8+ years old with 65,000 miles on it.
The car is probably good for 200,000 miles and we only drive it about 8,000 miles a year so it`s possible we might own it another 10 or 15 years. :)
The deciding factor for my changing vehicles is usually when:
1. I see something I think I have to have.
2. The vehicle we are driving starts showing rust.
Emphasis on #1.
#2 is automatic. Rust shows up, it`s fixed and the vehicle is gone.
In the 8+ years, I haven`t been interested in anything else so the GP could have an extended stay. :)

To the point:
Anyone have any ideas or experience with something to use to help reduce the rust on the undercarriage?
I spray it off with both the hose and a pressure washer regularly during the warmer months. During the winter, I periodically go through a drive-thru wash that does an underbody spray. Hopefully, that helps remove some of the road salt, but.....
There might be something I can spray on that would help. I`m not looking for something to dress it up for show. I want to stop as much of the corrosion as I can.

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Do you have access to a lift? You can spray the under carriage with PB Blast or equivalent. I do my truck at every oil change.

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Originally Posted by Maknmony

Do you have access to a lift?

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No.:cry:

Quote:

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Originally Posted by Maknmony

You can spray the under carriage with PB Blast or equivalent. I do my truck at every oil change.

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What is PB Blast?
(I`ll Google it in a minute.) :)
Found it. I`ll do some research on it.

Quote:

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Originally Posted by CharlesW

No.:cry:

What is PB Blast?
(I`ll Google it in a minute.) :)
Found it. I`ll do some research on it.

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I"m never without PB Blaster it is the best penetrating oil I have found. :bigups
Never thought about using it for undercarriage it is very thin how long would it last I would think driving in the rain would wash it off.

Quote:

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Originally Posted by CharlesW

Yes. :)
Actually, what I saw that bothered me was mostly suspension parts and springs. The GP is unibody and doesn`t have a frame as such, but it has a lot of supports under the body that hold things together. Rear axle, trailing arms, A frames in the front.
Chances are that the body will show rust long before any of those parts actually fail, but they do show some rust.

I hesitate to use any type of abrasive to clean the areas since I might remove enough paint from the painted parts to cause more problem than my efforts would cause good.

Maybe spraying some good old STP on everything would work. :D
Heck, maybe even some motor oil or a liquid grease would stick for a few months.
The tar like stuff that is available doesn`t seem like anything I would want to use.

Sheesh if I`m worrying about this kind of stuff already, it`s going to be a looooong winter. :wall

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Charles,

I know its a forbidden practice but long ago before my time the old timers used motor oil.You can also get a can of body schutz,or a can of the spray on bed liner at napa.

The oil treatment is a messy way to go and it must be done somewhere that it will soak up "dirt :wow: area".Spray the underside and fender wells and let it run off.Then drive down a dusty road and seal it up.Many old cars were done this way and years later you could still see the oil seeping out of some crevices.I know now green is in but iit works well but the oil and dirt makes for a messy underside.I would say you would be at the powerwash car wash for a while getting the dirty mess off.Total rust protection with a mess after...Every thing has a draw back right.

The second and somewhat cleaner way is this.

The body schutz or bed liner product is a great way to give color and durability to the undercarriage.It sprays on with a gun and drys hard and covers well.The cost per gallon is not that bad either.

Covering after a wire brush is a good way to go.You could sandblast and then cover but that is another messy job.


Just wanted to share some methods used around here...
:howdy

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Originally Posted by njcarting1

Charles,

I know its a forbidden practice but long ago before my time the old timers used motor oil.You can also get a can of body schutz,or a can of the spray on bed liner at napa.

The oil treatment is a messy way to go and it must be done somewhere that it will soak up "dirt :wow: area".Spray the underside and fender wells and let it run off.Then drive down a dusty road and seal it up.Many old cars were done this way and years later you could still see the oil seeping out of some crevices.I know now green is in but iit works well but the oil and dirt makes for a messy underside.I would say you would be at the powerwash car wash for a while getting the dirty mess off.Total rust protection with a mess after...Every thing has a draw back right.

The second and somewhat cleaner way is this.

The body schutz or bed liner product is a great way to give color and durability to the undercarriage.It sprays on with a gun and drys hard and covers well.The cost per gallon is not that bad either.

Covering after a wire brush is a good way to go.You could sandblast and then cover but that is another messy job.


Just wanted to share some methods used around here...
:howdy

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I like that idea. If the bedliner will stick to a rusty surface it would leave a durable covering.
I have used the spray can undercoating and it works well if you redo it every 2 years.

Quote:

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Originally Posted by CharlesW

No.:cry:

What is PB Blast?
(I`ll Google it in a minute.) :)
Found it. I`ll do some research on it.

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While you`re looking at PB Blaster take a look at Flluid Film.Lawn care guys use it to keep grass from building up under the mower decks.I use it on our pressure washing rig to slow down the rust on hose reels,bolts etc.

Quote:

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Originally Posted by Squirtgun

While you`re looking at PB Blaster take a look at Flluid Film.Lawn care guys use it to keep grass from building up under the mower decks.I use it on our pressure washing rig to slow down the rust on hose reels,bolts etc.

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I`m a big fan of Fluid Film in a variety of applications. It works well at keeping the chute on a snow-blower slippery. I also like it on firearms. It is a heavy bodied aerosol and tends to stay put. That said, I don`t think I would use it on the underside of a car. It`s too greasy.

Quote:

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Originally Posted by GearHead_1

I`m a big fan of Fluid Film in a variety of applications. It works well at keeping the chute on a snow-blower slippery. I also like it on firearms. It is a heavy bodied aerosol and tends to stay put. That said, I don`t think I would use it on the underside of a car. It`s too greasy.

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That`s the problem with anything with oil base its greasy.We all know oily products draw in dust and look like heck afterwards.That`s like using armor all on tires and wells,there are better cleaner options available.

Clean the underside and spray with the bed liner and walk away.Another spray can product Charles is HAMMERED PAINT.The stuff goes over rust and sticks quite well.I use this stuff religiously on the undercarriage.It will flake off if you don`t wire brush the flakier stuff.The cost is 7-8 bucks per can and works well.We have salt,sand,rocks and the like here at least 6 months a year to contend with.It just needs a touch up every spring and fall...:inspector::idea

Now that I"m retired and I"m home a lot more my vehicles don`t wear out they rust out :wall
Combating rust is a Major problem.

When I spray the underside with undercoating I wear paper throw-away overalls that they sell for painting because that stuff will settle down all over you.