Strongest undercoating ever?

With many restorations, you have to deal with rust repair. This in itself, can be a tedious task. What could make this task even more of a headache? Add in the extra factor of having to repair a rusty area that was undercoated from the factory. There is much debate as to which way is the best to remove what seems to be the “strongest coating ever known to man” (or so it feels that way every time I have to remove it!). I’ve personally tried many methods, from a propane torch heating it up and scraping it away, to a wire wheel on a angle grinder, to a straight up grinder. No matter how you go at it, you get either covered in the stringy mess or deal with the horrible smell when you heat that stuff up. When I came across the rust pictured on a VW I am restoring recently, I was lucky enough we had recently come out with this new product. Under Gone is designed to make this task much quicker and easier than the old “caveman-esque” ways of removing undercoating.

I started using a screwdriver to poke around and find the rust. Once I found the areas, I needed to “dig deeper” to find the extent of the rust. I also wanted to clean a large enough area that I could cut out the cancerous areas and weld in a new patch panel. Check out the pics below of what I found when “poking around”. I received this truck from a friend who told me it was “rust free” aside from some obvious rot on the floors. True to what I have learned, it is always good to poke around a bit, rather than taking the word of a previous owner!

After picking up a few cans of Under Gone (I ended up only needing one can, but now I have more for later!), I began liberally spraying the areas of concern. The undercoating used on 70’s & 80’s VW’s is nasty stuff! Because of this, I chose to go a little overboard and spray 2 layers of Under Gone on the areas. I sprayed the first coating on and waited until the “foaming action” was over and it had seemed to soak into the undercoating a bit. I then reapplied, and again waited for it to soak in. What I noticed was that the undercoating got much more flexible, and once I cut a edge into the area I wanted to scrape, it “peeled” off easily with the scraper. If I hit an area that seemed to be a little tough to scrape, I sprayed another bit of Under Gone on the area, let it soak in for a few minutes (perfect time for a sip of a cold beverage!), and went back at it.

In the end, this was a much less smelly, messy, tedious job because of the Under Gone. I was able to get the pieces cut out and replacements welded back in all in the same day! Hopefully this saves a few of our readers some time and frustration. Thanks for reading and keep bringing those classic rides back to life!


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