What undercoating do you think works best there?

Best undercoating based on preference?

  • Krown

    Votes: 1 7.7%
  • Corrosion Free

    Votes: 0 0.0%
  • Fluid Film

    Votes: 7 53.8%
  • Rust Check

    Votes: 1 7.7%
  • Engine Oil

    Votes: 3 23.1%
  • Frame Rails? What the **** are those?

    Votes: 1 7.7%

  • Total voters
    13
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g0thiac

G-Body Guru
Sep 6, 2020
939
582
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As the title asks. Not including rubberized undercoating, because that stuff is useless. If you haven't watched Eric's video on YT, heres the link.

 
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Clone TIE Pilot

Comic Book Super Hero
Aug 14, 2011
3,832
2,568
113
Galaxy far far away
G body frames are factory undercoated as they are wax dipped instead of painted. Aftermarket wax and oil undercoatings will attack the factory wax frame coating. The fix for this is a frame off, remove the factory wax coating, and then repaint the entire frame including inside the boxed sections. Part of the reason the rubber undercoating failed on that Chevy truck in the video is that GM still wax dips frames instead of painting them, and anything applied over the wax won't adhere correctly or even attack it causing rust issues. Even oil and wax based undercoating can still trap moisture and cause rust if not applied correctly. The underbody must be completely clean and dry of any moisture by drying it with heated blowers for a couple of hours before any undercoating can be applied and its best applied when the car is brand new. I did apply wax undercoating on my P71 Crown Vic since Ford paints its frames instead of wax dipping them like GM does.

If you do apply wax or oil undercoating, you will need a fine spray wand to only coat the body and carefully avoid spraying the frame itself. You will need a special spray gun and air compressor, aerosol versions suck as they don't adhere nearly as well.

My Regal was dealership undercoated back when it was new and only on the floor pans and wheel wells and they are still clean. Had to remove undercoating from my rear wheel wells to reseal the sheet metal seams that were leaking water but the underlying metal was clean under the rubber undercoat. Repainted the seam areas after resealing them and applied replacement rubber undercoat.
 
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mikester

Comic Book Super Hero
Mar 10, 2010
2,904
3,641
113
Small town NY
A guy I know that does body off customs uses Upol Raptor bedliner on most of the vehicles that he builds. If it was out when I did my 81 I would have used it without hesitation. It looks great and seems to hold up very well. I wound up using 3M Body Schutz. Used it on the bottom of the wagon as well. At the time I didnt know about Raptor. Im sure it will be problem free since the cars are kept in a heated garage during the Winter and will never see road salt.
I started using the Body Schutz back in the early-mid 80s when I was into Jeeps and 4x4s. Worked well back then.
 
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Rt Jam

G-Body Guru
Mar 30, 2020
579
558
93
Ontario Canada
Products like Krown and Rust Check will creep into areas that were not sprayed. That is good but it also does not last. It will be worn off before one winter in many areas and laid on heavy in areas that are not needed. It is for a fact, better than nothing but nobody sprays everywhere it's needed. It's also hard to know where every different car needs it. Either way, any oil spray is better than nothing but nothing beats just avoiding the salt in the first place.

If you truly want to preserve your car, don't drive it. As for undercoating like South Main is talking about, avoid.
 
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g0thiac

G-Body Guru
Sep 6, 2020
939
582
93
Products like Krown and Rust Check will creep into areas that were not sprayed. That is good but it also does not last. It will be worn off before one winter in many areas and laid on heavy in areas that are not needed. It is for a fact, better than nothing but nobody sprays everywhere it's needed. It's also hard to know where every different car needs it. Either way, any oil spray is better than nothing but nothing beats just avoiding the salt in the first place.

If you truly want to preserve your car, don't drive it. As for undercoating like South Main is talking about, avoid.
Agreed, that is the most best way to make sure it doesn't rot underneath.

I have heard stories of people though, who've driven their cars for decades and they still look brand new from undercoating. Mind you, they wash the outside of the vehicle constantly and spray it themselves to know where exactly the hidden spots are!
 
Nov 4, 2012
5,998
12,671
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I'm a fluid film believer. Used it on my old F150 after restoring it and none of the rust ever came back even after driving it through a couple PA winters. I use it on my tractor, snowblower and all of the implements before I store them and they always look like new when I go to use them again. I wanted to do my new F150 with it before winter but just didn't get around to it. Eventually I'll coat it.

It does need reapplied occasionally and it is messy, but if keeping rust down is your goal, it works well.
 
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g0thiac

G-Body Guru
Sep 6, 2020
939
582
93
I'm a fluid film believer. Used it on my old F150 after restoring it and none of the rust ever came back even after driving it through a couple PA winters. I use it on my tractor, snowblower and all of the implements before I store them and they always look like new when I go to use them again. I wanted to do my new F150 with it before winter but just didn't get around to it. Eventually I'll coat it.

It does need reapplied occasionally and it is messy, but if keeping rust down is your goal, it works well.
How often should I apply it if you don't mind explaining haha? Theres a place that does fluid film spraying near Toronto, so hoping to use them.
 

Flyers9928

G-Body Guru
Jul 30, 2014
597
1,515
93
South Central Pa
East Wood internal frame coating. Comes with a 24 inch wand to get in to the frame rails. On the outside, I use epoxy primer and then bed coating. I scored some Por15 truck bed coating last year for like $30 a gallon. Its grey but can be painted. I plan to hit it with some chassis or flat black come spring.
 
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Maverick's_Monte

Greasemonkey
Sep 15, 2011
172
163
43
Rhode Island
I've used fluid film on my monte and Ranger with great results. Yeah, you have to do it every 2 years or so depending on where you are and when you drive it; certainly not a one and done solution but i have had good luck with that product. I usually buy the gallon of the stuff, add a bit of hydraulic oil, just a bit, to thin it out (helps it come out of the gun) and borrow my friends spray gun with the 360 degree spray wand and various other nozzles. I have been meaning to purchase the spray gun kit for myself, but haven't pulled the trigger.
 
Nov 4, 2012
5,998
12,671
113
How often should I apply it if you don't mind explaining haha? Theres a place that does fluid film spraying near Toronto, so hoping to use them.

Once every year or two. You can buy the spray cans and touch up the high wear areas too.

I paid to have it sprayed the first time, then the next year I bought the spray gun and frame wands and a 5 gallon pail of fluid film and I do it myself. A gallon will usually do one average sized vehicle. I lay it on heavy and it took me probably gallon and a half to do my supercab long bed F150 that was over 19' long.
 
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