Undercoat or Not???

[mrclueless]

My dealer is one of those that wants to add on all sorts of fabric protectors, paint sealant and undercoat. I figure I can Scotchgard the interior and have found that reasonably regular waxing does a great job in maintaining the finish. So the only thing I am wondering about is undercoat. The front wheel wells are all plastic so I don't see much benefit there. The rear wells have undercoating from the factory but behind the wheels there is an open area that goes all the way to the top of the bed rails. The Nissan manual says corrosion protection is covered for the life of the vehicle. The dealer says the undercoating is incredibly wonderful, decreases road noise and is guaranteed for ten years against flaking off.

Any body find that undercoating has any real benefit??

[joekrz]

Originally Posted by mrclueless

My dealer is one of those that wants to add on all sorts of fabric protectors, paint sealant and undercoat. I figure I can Scotchgard the interior and have found that reasonably regular waxing does a great job in maintaining the finish. So the only thing I am wondering about is undercoat. The front wheel wells are all plastic so I don't see much benefit there. The rear wells have undercoating from the factory but behind the wheels there is an open area that goes all the way to the top of the bed rails. The Nissan manual says corrosion protection is covered for the life of the vehicle. The dealer says the undercoating is incredibly wonderful, decreases road noise and is guaranteed for ten years against flaking off.

Any body find that undercoating has any real benefit??

Well if you live in an area of the country that has snow and uses salt on the roads during winter, I would definately get it done. I am having mine done this Saturday. The panels are only galvanized on the interior side and will eventually rust. The only thing Nissan did was the wheel wells. Vehicles rust from the inside out not the other way.

If you look in the Nissan manual on Page 7-3 it states that if you live in areas where road salt is used in winter then it is necessary to clean the underbody regularly in order to prevent dirt and salt from building up and causing accelerated corrosion on the underbody and suspension. Page 7-5 suggests getting rust protection for the underbody if you live in an area that uses salt and other chemicals. Getting it done eliminates the need to wash the underbody.

And yes, it does decrease road noise. Most places will offer lifetime warranty if you bring it in to get checked once a year.

[Kilroy]

I would absolutely not undercoat. I live near Buffalo, NY where they use straight salt on the roads so I did a bunch of research in this area as well and I decided that undercoating could cause more problems than it fixes:

o Plugs factory drainage points holding in moisture and salt
o If not properly applied it could seal in existing moisture
o It could crack and allow moisture in
o It could make maintenance under your truck a nightmare with coated parts, bolts, etc.

Basically, the recommendations I found most prevalent were to either do nothing or keep your car washed regularly, or to consider an oil bath for the underside of your vehicle. An oil bath is just a spray all-over the underneath with used motor oil and it needs to be done annually.

If you do decide to get your ride undercoated I would be interested in hearing your thoughts afterward as far as whether it truly affects maintenance or access under your truck.

[drparrothead]

Don't do it...I worked for a dealership that really pushed the add-on stuff. Not that there isn't good undercoating out there it's just that dealerships buy the cheap crap by the drum and it is simply a waste of your money. These add-ons or so-called appearance packages are often times pushed b/c the salesman must sell so many of them in order to qualify for his sales "ladder" for the month. In some dealerships you make as much off of your ladder comissions as you do on your straight percent of gross. Be very wary of undercoating, "paint sealer", leather "treatment", so on. Bottom line, 95% profit on the junk for the dealer and no benefit to you. This info my friend is from my experience on the dark side. Go to a reliable aftermarket place if you want undercoating (and make sure they steam clean it and dry it well b/f application).

[TriKKy]

Originally Posted by Kilroy

I would absolutely not undercoat. I live near Buffalo, NY where they use straight salt on the roads so I did a bunch of research in this area as well and I decided that undercoating could cause more problems than it fixes:

o Plugs factory drainage points holding in moisture and salt
o If not properly applied it could seal in existing moisture
o It could crack and allow moisture in
o It could make maintenance under your truck a nightmare with coated parts, bolts, etc.

Basically, the recommendations I found most prevalent were to either do nothing or keep your car washed regularly, or to consider an oil bath for the underside of your vehicle. An oil bath is just a spray all-over the underneath with used motor oil and it needs to be done annually.

If you do decide to get your ride undercoated I would be interested in hearing your thoughts afterward as far as whether it truly affects maintenance or access under your truck.

100% agree from Rochester, NY. Undercoating is the quickest way to mess something up and not know about it until its too late.

[joekrz]

Obviously those of you that say don't do it DON'T know what you are talking about and DON'T know the damage that road salt can do. My last truck was 12 years old and was undercoated from day one and made it 12 years without ever rusting. Take a look at the attached pictures. I can guarantee that if this truck wasn't undercoated, it would have been a rust bucket. Why do you think Nissan undercoated the wheel well area? Because that is the most vulnerable place for corrosion to start. Other places that are good for rusting are the bottom of the tailgate, floor boards and the rear bumper if it is not coated on the back side. I've witnessed these things first hand on vehicles that have no undercoating. I have been living in Northern WI and MI for the past 24 years and can tell you that vehicles without undercoating will eventually rust from the inside out.

Oil sprays are just surface protection. Oil washes off with the weather elements. Undercoating, being a manmade substance, is more durable.

The place I am going to is an aftermarket Z-Tech/Line-X dealer They charge $300 and have a lifetime warranty against rust or peeling. They said bring it once a year and if any is peeling they re-spray at no charge.

[Zardoz]

Originally Posted by joekrz

Obviously those of you that say don't do it DON'T know what you are talking about and DON'T know the damage that road salt can do. My last truck was 12 years old and was undercoated from day one and made it 12 years without ever rusting. Take a look at the attached pictures. I can guarantee that if this truck wasn't undercoated, it would have been a rust bucket. Why do you think Nissan undercoated the wheel well area? Because that is the most vulnerable place for corrosion to start. Other places that are good for rusting are the bottom of the tailgate, floor boards and the rear bumper if it is not coated on the back side. I've witnessed these things first hand on vehicles that have no undercoating. I have been living in Northern WI and MI for the past 24 years and can tell you that vehicles without undercoating will eventually rust from the inside out.

The place I am going to is an aftermarket Z-Tech/Line-X dealer They charge $300 and have a lifetime warranty against rust or peeling. They said bring it once a year and if any is peeling they re-spray at no charge.

No what they are saying is an improper undercoating job is worse than
nothing. They are pointing out that prep work, material choice, and proper
application methods need to be done. Having some guy who just sprays
some tar like stuff underneath without cleaning and drying is not proper
undercoating and many places are doing this to make money.

Zardoz

[joekrz]

Originally Posted by Zardoz

No what they are saying is an improper undercoating job is worse than
nothing. They are pointing out that prep work, material choice, and proper
application methods need to be done. Having some guy who just sprays
some tar like stuff underneath without cleaning and drying is not proper
undercoating and many places are doing this to make money.

Zardoz

The place I am going to cleans and dries before applying.

[smoothTitan]

i think il do a frame off and powder coat everything. not exactly realistic but it would be nice.

[TitanBrian]

The body and frame steel is primed before paint and assembly. So, additional coating may offer added barrier resistance to electrolyte, if it is 100% adhered to the metal and does not allow any water/salt to get under it and dwell. For the nastiest, most icy, wet wicked environs, it might help. Anywhere else, well.....

rant off.

Brian

[calgary_redneck]

I live in canada where lots of salt is used on the road and I can tell you that undercoating is the last thing I would ever ever do. As already mentioned undercoating clogs up drainholes, gets porus with age allowing moisture to get trapped beneth it. Also oftain it is carlessly appied getting in unwanted places (such as mechanical components). Undercoating is one of the biggest scams of the last 30 years dealers have made millions off selling it as well as aftermarket companies and the problems it causes don't appear for years down the road generally.

[Tom Roper]

I have to agree, that it sounds like most of the naysayers don't have any first hand experience with undercoating.

To me, the Titan underbody looks like a rusting tin can waiting to happen, (or already happening.) If it's already started, undercoating won't stop it. If it hasn't, it will start as soon as your offroad tires throw enough stones to poke through the finish.

Brian seems to say something about corrosion, due to cathodic potentials, which is just what it is, ionization (electrical currents) in the presence of an electrolyte (salt water).

One way corrosion has been managed in sea-going vessels is using a sacrificial anode. It is simply another metal lower on the galvanic scale in surface contact with the metal you are trying to protect. The sacrificial anode being lower on the galvanic scale will cause an electrical current to flow in the presence of the electrolyte, but the anode will sacrifice its own hydrogen ions (oxidation) instead of depleting the ions in the metal you want to protect. The sacrificial anode turns to rust instead.

[TriKKy]

Originally Posted by Tom Roper

I have to agree, that it sounds like most of the naysayers don't have any first hand experience with undercoating.

Actually, it seems to me that all the naysayers are from places like Canada and Buffalo and Rochester, NY...you're right, what would they know about undercoating and dealing with bad winters No no, I suppose the people you should believe are those that SELL it, or those that have to justify the fact that they had it done. Sure, their truck may have been OK at the end, but then again, you don't know exactly how it would be without it AND maybe they even got lucky with a 100% install. What we are saying is that it is NOT worth the chance you take. There really is no clear benefit since if the install is messed up, you are 2x as screwed as you were before. TAKE IT FROM THE PEOPLE WHO HAVE EXPERIENCE and just keep your underbody clean.

If you don't believe us:
Go do a google group search and look for ziebart or undercoating and you will find MANY people who will give you the SAME answers as the people who aparently "don't have any experience." I did a search and wasn't really able to find one thread where someone asked about undercoating where the people were told it was a good idea...without fail, they all said not to do it. Give me a break.

As long as we are on the "people who don't have experience" do a google search on the anode crap as well. Just because I don't have it on my car doesn't make it any more believable or likely to work. There are TONS of comparisons and studies with them and while they do work in their immediate area, they DO NOT work on the entire underside of your car...sorry.

Edit: Grr...sorry, pissed off at stupid comments...here are some threads of people "who have experience" (I only used Ziebart b/c they are big, but the fact of the matter is that rust proofing is rust proofing anywhere by anyone):

http://groups.google.com/groups?q=zi...eja.com&rnum=4

http://groups.google.com/groups?q=zi...ome.com&rnum=5

http://groups.google.com/groups?q=zi...tv.net&rnum=14

Electronic:

http://groups.google.com/groups?hl=e...net%26rnum%3D2

[srvfan]

Originally Posted by Zardoz

No what they are saying is an improper undercoating job is worse than
nothing. They are pointing out that prep work, material choice, and proper
application methods need to be done. Having some guy who just sprays
some tar like stuff underneath without cleaning and drying is not proper
undercoating and many places are doing this to make money.

Zardoz

When restoring my old z car i was shocked at the rust we found UNDER the undercoating. moisture had gotten trapped between the metal and the coating. It looked fine on the surface untill we started scraping and then things went downhill in a hurry. I'm torn as ithink it would be great as long as stuff didn't get stuck under it.

[srvfan]

Originally Posted by srvfan

When restoring my old z car i was shocked at the rust we found UNDER the undercoating. moisture had gotten trapped between the metal and the coating. It looked fine on the surface untill we started scraping and then things went downhill in a hurry. I'm torn as ithink it would be great as long as stuff didn't get stuck under it.