Rubberized undercoating a bad idea?

DropTopDon

TJ Enthusiast
Original poster
Joined
Nov 7, 2019
Messages
642
Location
VA
Hello everyone, is rubberized undercoating a bad idea? I have a few cans of rustoleum rubberized undercoating spray and I was planning on using them. I also wanted to use it to paint the exterior my frame after cleaning it and wire wheeling it. I plan on fluid filming the inside later this month. I have seen on the forum that people say they dislike rubberized undercoating because it turns to a gooey substance when they are trying to remove it, and that the rust still forms but it is just hidden underneath the rubberized coating. My questions are, why would one remove the undercoating, and if I am to fluid film the interior of the frame could rust still form under the rubberized coating?
 
Any imperfection can enable moisture from getting under the coating. I’d stay away from it, unless you are going to completely and thoroughly clean and prep the frame, like it was to be painted, and then completely coat it.

Have you ever seen factory clear coat peel off? It starts small with a defect in the surface, letting the smallest amount of moisture in. Then the sun turns that into steam, which expands starting to create a pocket where more moisture collects and repeats the cycle.
 
My wifes car (6 years old) has a rubber undercoating which this summer started to flake off. Under it the metal looks like it was sitting at the bottom of the ocean for 6 years. We are in the middle of trying to work it out with the dealership/undercoating place (both owned by the same guy but both blaming each other).

Por15 or Eastwood then Fluidfilm.
 
My wifes car (6 years old) has a rubber undercoating which this summer started to flake off. Under it the metal looks like it was sitting at the bottom of the ocean for 6 years. We are in the middle of trying to work it out with the dealership/undercoating place (both owned by the same guy but both blaming each other).

Por15 or Eastwood then Fluidfilm.
Maybe add naval jelly before Por15...
 
Coating the outside of the frame does nothing except help cosmetically and it will most likely be a pain in the ass down the road. It will also stop any smart buyer from purchasing it if you decide to sell in the future.
 
If you‘re familiar with long term firearm storage, cosmoline is a great metal protectant/rust preventer. It’s designed to last decades. There are spray cans of it as well. If the metal is rust free, spray it with this and pretty much only mineral spirits will remove it. It’s a bit stinky for the first few days after using also. Multiple companies make it, but AMSOIL is the cheapest per oz.
https://www.amsoil.com/p/heavy-duty-metal-protector-amhsc/
 
Coating the outside of the frame does nothing except help cosmetically and it will most likely be a pain in the ass down the road. It will also stop any smart buyer from purchasing it if you decide to sell in the future.
Even if I decide to use POR 15 for the exterior of the frame? I plan on flushing the interior of the frame and coating it as well. Hopefully I never sell my TJ either 🙂
 
Even if I decide to use POR 15 for the exterior of the frame? I plan on flushing the interior of the frame and coating it as well. Hopefully I never sell my TJ either 🙂

The outside of a TJ frame doesn't matter at all besides how it looks cosmetically. I would put whatever you think looks the best and wouldn't be terrible to remove (maybe paint for example). You don't have to worry about rust when it comes to the outside. The inside of the frame is where you should spend most of your time, since rust in there can cause expensive problems. Anything you think looks good and are comfortable with is great for the outside :)