Quote:
Originally Posted by Army
Never ever ever use a pressure washer on the underside of a car if you are in a damp / wet climate. You will manage to push water into more places where it shouldn't be.
I don't have a quick solution for cleaning the crud off of the underside - I use engine de-greaser and careful scrubbing with a brush. The best way of removing the stupid rubber Mercedes factory fitted undercoating is to use a powerfull hot air gun / blow torch with a rigid paint scraper (the type you'd normally use on window frames).
If the metal is rusted underneath you can easily remove the undercoating with your fingers - if you were to use a pressure washer you'd blast straight through it; possibly past the rust or through it pushing water into places where you can't dry it out. If water gets between the spot welded joints on these monocoque constructions you may as well kiss your car good bye.
|
I never thought of it that way! Interesting observation though. I had a rust hole appear seemingly out of nowhere on my left rear dogleg. It just looked like a bubble the size of a 25 cent coin. I poked it with a screwdriver and it ended up with this huge hole almost the width of the dogleg! Further poking revealed a another hold on the inner side of the fender. How water got in there is beyond me....but it could've been because of years of pressure washer usage on the underbody.
I would like to tear off that underbody rubbery thing as it as started cracking here and there. Not sure if its advisable though.