Undercoating

We are buying a new Chrysler mini-van, and must decide if we want a
rustproofing/undercoating. When we bought the last one, many reports in
media said this was not needed- factory rustproofing was adequate.
Main reason we are buying a new one is the old one is rusting out.

What are your opinions on undercoating? Are there third party shops as
good, maybe cheaper, than the ones dealers work with? I am sure dealers
get their cut from the places the dealers send them to.

Don Stauffer wrote:
>
> We are buying a new Chrysler mini-van, and must decide if we want a
> rustproofing/undercoating. When we bought the last one, many reports in
> media said this was not needed- factory rustproofing was adequate.
> Main reason we are buying a new one is the old one is rusting out.
>
> What are your opinions on undercoating? Are there third party shops as
> good, maybe cheaper, than the ones dealers work with? I am sure dealers
> get their cut from the places the dealers send them to.

I would say it largely depends on what climate you are in and the amount
of maintenance you do on your vehicle.

In the "rust belt" areas with lots of sand and salt on the roads in the
winters I think the undercoating will help considerably since the
"factory rust proofing" a.k.a. paint / primer doesn't hold up well to
the sand and ice hitting it and leaves the metal more exposed to rust.
The undercoatings are fairly waxy / rubbery and should resist the
impacts better, even when cold.

In drier hotter areas without road salt the undercoatings are probably
not worthwhile since the underbody doesn't see as much of a physical
assault.

The undercoatings do make it rather nasty to try to work on stuff under
the vehicle, particularly in hot weather when they are softest.

Even in the "rust belt" you will probably be ok without the undercoating
-if- you wash the sand and salt from under the vehicle at least every
few days during the winter, -and- crawl under the vehicle in the spring
and repair any damage to the underbody properly i.e. clean, prime and
paint.

The undercoating can also hide rust that is forming beneath it, making
it more difficult to catch and repair before it rusts through.

Pete C.

Pete C. wrote:
> Don Stauffer wrote:
>
>>We are buying a new Chrysler mini-van, and must decide if we want a
>>rustproofing/undercoating. When we bought the last one, many reports in
>> media said this was not needed- factory rustproofing was adequate.
>>Main reason we are buying a new one is the old one is rusting out.
>>
<snip>
>
> Even in the "rust belt" you will probably be ok without the undercoating
> -if- you wash the sand and salt from under the vehicle at least every
> few days during the winter, -and- crawl under the vehicle in the spring
> and repair any damage to the underbody properly i.e. clean, prime and
> paint.
>
> The undercoating can also hide rust that is forming beneath it, making
> it more difficult to catch and repair before it rusts through.
>
> Pete C.

I live in the "rust belt" and have never had a rust problem on a car and
have never rustproofed or undercoated. The cars were driven 5 to 9 years
with mileage from 85,000 to 150,000. BUT..., I did get the undercarriage
cleaned often when going through the car wash (at least once a month in
winter). Never went underneath to "repair".

I agree with the last statement about hiding the rust. Also, if moisture
gets underneath the coating it can accelerate the rusting. Most of the
rustproofing jobs also spray inside the doors by drilling a hole and
that breaks the factory rust inhibitor and the first place to rust is
.... around the hole.

Wayne

Don Stauffer wrote:

>We are buying a new Chrysler mini-van, and must decide
>if we want a rustproofing/undercoating.

>When we bought the last one, many reports in media said this
>was not needed- factory rustproofing was adequate. Main
>reason we are buying a new one is the old one is rusting out.

Vehicle owner's manuals warn against having aftermarket rustproofing
applied and say it can make rust problems worse or even void the
factory rust-through warranty. Considering that most aftermarket rust
treatment warranties have a clause that limits repair coverage to the
cost of the original application while the factory rust warranty has no
such limit, I'd follow the manufacturer's advice.

The problems with aftermarket rustproofing are that the surfaces can't
be cleaned wll enough to make it stick well, some surfaces are
naturally anti-stick (doors and enclosed rear fenders have 3M Sealwax
applied to them -- pull off a door panel and you'll see a sticky
substance in the bottom 6"), drain holes are often clogged during the
application of rustproofing (I once saw a door with 4" of water in it),
and enclosed areas are rarely completely covered (state of NY found
bare spots in 24 out of 25 rustproofing jobs checked).

The founder of the company I work for often told us, "We don't sell
rustproofing," meaning we weren't allowed to sell customers anything
useless or just to increase the profit margin.

Skip the unneeded and possibly harmful aftermarket rustproofing and use
the money saved to pay for extra fluid changes for the awful Chrysler
automatic transmission (the anti-Torqueflite). Why anybody would buy a
vehicle with that transmission in it is beyond me (as is why it's still
below-average in reliability 15 years after its introduction), now that
there are so many good Japanese minivans available. After all it's not
as if Chrysler is an American brand.

Don Stauffer wrote:

> We are buying a new Chrysler mini-van, and must decide if we want a
> rustproofing/undercoating. When we bought the last one, many reports
> in media said this was not needed- factory rustproofing was
> adequate. Main reason we are buying a new one is the old one is
> rusting out.
>
> What are your opinions on undercoating? Are there third party shops
> as good, maybe cheaper, than the ones dealers work with? I am sure
> dealers get their cut from the places the dealers send them to.



Factory "rustproofing" tends to be limited to zinc galvanizing or zinc
primers. The problem with these is that the stuff gets severely
sandblasted afer a few years on salt-and-sand laden roads. This
sandblasting wears away the paint, exposing the primer, which rapidly
loses its effectiveness. The result: Rust.

Also, inside the crimps and pinchwelds, where water sits for ages, the
zinc is either non-existent or is rapidly consumed, again leading to
rust. The gummy and rubbery stuff cannot protect against this sort of
rust, as it's internal to the structure of the car. Only the drippy
stuff is effective.

Properly applied rubber-based undercoating, combined with yearly
"drippy" treatments, is the best way to go. The rubber protects the
paint from sandblasting, while the drippy stuff keeps water from
settling in any crevices that might exist or develop.

Of course, if you're not in Canada, the drippy stuff is unavailable to
you.

Hugo Schmeisser wrote:

> Properly applied rubber-based undercoating, combined with
> yearly "drippy" treatments, is the best way to go. The
> rubber protects the paint from sandblasting, while the
> drippy stuff keeps water from settling in any crevices
> that might exist or develop.
>
> Of course, if you're not in Canada, the drippy stuff is
> unavailable to you.

Is the drippy stuff called Finnegan's Waxoyl?

Doesn't the drippy treatment cause dirt to stick and help hold moisture
and road salt?

larry moe 'n curly wrote:

>
>
> Hugo Schmeisser wrote:
>
> > Properly applied rubber-based undercoating, combined with
> > yearly "drippy" treatments, is the best way to go. The
> > rubber protects the paint from sandblasting, while the
> > drippy stuff keeps water from settling in any crevices
> > that might exist or develop.
> >
> > Of course, if you're not in Canada, the drippy stuff is
> > unavailable to you.
>
> Is the drippy stuff called Finnegan's Waxoyl?


No. That's the gummy stuff.


>
> Doesn't the drippy treatment cause dirt to stick and help hold
> moisture and road salt?


Nope. The real drippy stuff is astonishingly effective. Dirt does
stick, but it tends to build up a patina that holds the oil onto the
surface longer.
http://www.rustcheck.com/

why me wrote:

> I live in the "rust belt" and have never had a rust problem on a car and
> have never rustproofed or undercoated. The cars were driven 5 to 9 years
> with mileage from 85,000 to 150,000. BUT..., I did get the undercarriage
> cleaned often when going through the car wash (at least once a month in
> winter). Never went underneath to "repair".
>

I never believed in rustproofing (still pretty much don't see the need)
but my old winter beater was a 70 Buick that I bought in 96. The thing
had all these yellow plugs where it had been Minged. I dunno if it was
done on a regular basis or what, but it had hardly any rust, even when
we turned it into a demo derby car in 2004. (I got the car cheap
because it needed a tranny.)

Hello Larry, Have used Finnegans waxoil very successfully in the past
here in the UK.
Also regular automotive grease rubbed over all the subrame parts,
I have also had great success spraying oil over everything underneath.
You would need to keep it off rubber parts and the exhaust.
Thinking back to when my father had a car in the 1960`s , I remember
the effect of those rubberized "underseal" coatings. They look great
new, but eventually salted winter road water
gets behind it and the car is ruined.
The drippy stuff (oil) waxoil) and grease is best.
If you REALLY want to keep the car you could spray it with oil
underneath getting into all the crevaces before salt is on the road in
Autu mn before salt is applied to the roads. Then in Spring get it
steam cleaned after the last road salt, giving it a light spraying with
oil (thinned with paraffin a little) after it has thoroughly dried.
This twice a year oil spraying and once a year steam clean, would
really make it last.
You can even miss the steam clean and just hose and brush the road crud
and salt off.
If you do none of this, hose it underneath every weekend in winter.
Most of our cars here are now fully galvanized.Even the seams on doors
etc, are sealed at the edges.
But in 1960/ 70s, our cars in the UK did not have proper galvanizing,
only some sort of electro plating with paint over it. Under these
conditions I oil sprayed a mini van regularly and there was no rust
underneath at all after 9 years. Other examples of the same model had
perforating rust in the sills and wheel arches and rear subframes
crumbling away after about 5 years.
Personally, I would not pay for an expensive ,one off , rustproofing
session when you can do it yourself on a set of drive on ramps, so
cheaply.
Regards from the UK.

"Don Stauffer" > wrote in message
...
> We are buying a new Chrysler mini-van, and must decide if we want a
> rustproofing/undercoating. When we bought the last one, many reports in
> media said this was not needed- factory rustproofing was adequate. Main
> reason we are buying a new one is the old one is rusting out.
>
> What are your opinions on undercoating? Are there third party shops as
> good, maybe cheaper, than the ones dealers work with? I am sure dealers
> get their cut from the places the dealers send them to.

No. Better to have the car wash do the undercarriage every couple of
months. I haven't had this done in 25 years. Had some vehicles for 10-15
years and not had a rust problem.