Undercoating has worn away. Touch-up or remove it?

[KrisZ]

Unfortunately you were sold snake oil and because you paid good money for it, you feel it provides some benefits and want to "protect" your investment. The fact that is has worn off so much just after one year proves its a bad product and will not provide any rust protection.

Also, I don't think any oil rust proofing product will cause this rubberized coating to lift, at least I have not seen it with my vehicles. My old Mazda 3 came in sprayed with something either from the factory or by the dealer and that thing was not impacted by any of the rustproofing oils I have used over the 14 years I owned it and I used several types.

I would not worry about it lifting. Even if it does, oil type rustproofing will creep into these places anyways. That's its major advantage.

 

[demarpaint]

Noxudol is the best bar non, 300 for the underbody and 700 for the inside panels. Amazon carries it.

Noxudol 300 500ML Aerosol Can | Spray Undercoating | Noxudol 300

Noxudol 300 500ML Aerosol Can is a rust preventive product free from solvents. Low viscosity binding agents and additives have been mixed with enable application at a low temperature.

www.noxudolusa.com

I don't see it in gallons to be sprayed from a rustproofing gun? Does that exist?

 

[Sequoiasoon]

I remember reading the rubberized horror stories many times over the years. I wanted to do the Sequoia when new with Krown or oily version but travel distance and $$ made that difficult. Wish I had as it rotted from multiple spots and even had Toyota do their version as part of frame recall.

Funny part with Pilot and I know I posted in some forums. I had the Pilot done with FF about a 1-2 weeks after purchase. One of the first service appointments I told the service manager to tell the mechanic what it was since many around don't have it, they didn't.

I'm standing by glass service bay doors and see mechanic put my Pilot in the air. He looks and grabs a flashlight. He walks away and comes back with 2-3 other techs all with flashlights. All of them freaking out looking for a massive oil leak with their lights. I tap on teh door and they let me in. I explain the FF and the look of relief on their faces was actually comical. They weren't sure how to tell the service manager about the massive leak otherwise.

Dirty, greasy when I work on it BUT my hands are soft and clean up easy.

 

[Sequoiasoon]

Noxudol is the best bar non, 300 for the underbody and 700 for the inside panels. Amazon carries it.

Noxudol 300 500ML Aerosol Can | Spray Undercoating | Noxudol 300

Noxudol 300 500ML Aerosol Can is a rust preventive product free from solvents. Low viscosity binding agents and additives have been mixed with enable application at a low temperature.

www.noxudolusa.com

Checking link, the 900 and 1600 almost sound like a version to avoid. The 1600 says "After drying, it forms a solid and elastic film" which to me doesn't sound great.

The 300 and 700 sound better.

@Trav - have you tried the thicker ones? Are they good if on a new vehicle? From all the readings especially on the older vehicles is that the more oily versions at least also seep into any rusty areas to help that. Does the 700 cavity wax breath/self heal?

 

[finmile]

I just moved to Lower mainland BC from southern Alberta and neither of these places use much if any road salt..

Salt is the killer. If you keep on washing it away from the frame a couple of times each winter, I think that helps alot.

 

[Snagglefoot]

Lucky you. I recall looking at new Chevy trucks and they would have surface rust on the frame—new on the lot.

At times I think “low rust” just means you can still see threads and bolt heads on the bits underneath. At some point everything morphs into one ugly mess.

Yep. I make an effort to spray Krown on all threaded suspension pieces every time I change out the winter tires. You’ll thank yourself when it comes time to replace anything. If a person is leasing, this doesn’t matter unless you intend to buy out the lease.

 

[97prizm]

I have a year old F150. I had rubberized undercoating done when the truck was brand new, however the undercoating has worn away significantly after a year much to my surprise. There are numerous rock chips in undercoating in the wheel wells, and around 10-20% of the coating has completely worn away on the frame. I'm not too concerned about the wheel wells as its a aluminum body truck, but the frame is still steel. I want to keep this truck long term and drive it until the wheels fall off.

As such I am having trouble deciding what to do. It seems like the proper thing to do now is to remove the remaining undercoating completely, as now that it is chipped and worn to my knowledge moisture can start to creep under and get trapped, accelerating rust. However, in the places where it is worn and overall there is minimal to no rust. So I'm curious how bad it would be long term to just touch it up with some undercoating from a spray can. Seems like removing the rest of the undercoating would be a complete chore, and not sure if I can find a shop willing to do it. Haven't asked around yet but I'm assuming it will be a lot of $$$.

Here is a quick video to show where it is worn. The brownish looking areas are where there is still undercoating (it tends to attract dust). The black is where its bare steel:

Go to your local auto parts store and look for undercarriage coating I think it's Dupont. It's in a white, red, and black can. They also have a "commercial " version as well.

 

[doitmyself]

Salt is the killer. If you keep on washing it away from the frame a couple of times each winter, I think that helps alot.

In addition to under carriage rust, in the U.S. rust belt the salt vapors gets into the interior body panels and rots the sheet metal from the inside out. Once you see the rust blisters, it's too late. I have no buyers remorse getting my vehicle Krowned annually.

To the OP, you can't change what was already done. Live and learn. I might be inclined to let it go another year. Monitor it and when it starts peeling off more, then apply an oil product? It's a tough call either way, with no single correct answer. Would a good pressure wash knock off that product? Then oil spray?

 

[finmile]

I would vote for yearly oil spray (like fluid film, krown etc) at least to places where the previous undercoating is peeling off. It’ll seep into rust and under the previous undercoating and force water/moisture out. And spray the oily undercoating also to interior parts of frames/rocker panels/wheel wells etc at least once from any holes that are available. As stated in the previous post, it’s important to prevent rust forming also from inside out.

You can use this kind of 360 degree long nozzle to spray the interior parts. You can fish the nozzle in from the water drain holes.

 

[Zenon]

+1 for Noxudol. As a long-time Fluid Film user tried last year this Swedish wax. It is holding up really well, with no problems with a pressure washer cleaning. 700 is a sort of Fluid Film with the ability to thicken (still soft to the touch). It also has rust inhibitors which can slow down/stop existing rust.

In the picture, Subaru Outback differentials coated with 700 and subframe coated with 300 (700 in cavities) after one salty Vermont winter.

 

[Trav]

I don't see it in gallons to be sprayed from a rustproofing gun? Does that exist?

AFAIK it comes in aerosol cans and litre cans for undercoating/rustproofing guns. The 700 in the aersol cans comes with a wand if you buy the package. You have to check that out, Amazon has the 300/700 aerosol cans as a kit.

Checking link, the 900 and 1600 almost sound like a version to avoid. The 1600 says "After drying, it forms a solid and elastic film" which to me doesn't sound great.

The 300 and 700 sound better.

@Trav - have you tried the thicker ones? Are they good if on a new vehicle? From all the readings especially on the older vehicles is that the more oily versions at least also seep into any rusty areas to help that. Does the 700 cavity wax breath/self heal?

No I haven't, I don't like the idea of a "solid and elastic film" either. Both self heal and will not trap moisture.

 

[finmile]

A lot of good options in this thread for the OP how he could proceed in the future.

Here’s another good video against rubberized undercoating. Yuck!