undercoating...again

I've been researching in other forums about cleaning the underbelly of cars. Someone said that this would only speed up the rust process. Is this true?? I thought that removing the foreign particles would help prevent rusting. What if undercoating was applied? (would it still speed up the rusting process?)

Get it bottom blasted at a good car wash...let dry a few days...then dump a few gallons of driveway sealer on the drive, and go do some donuts on it...killing two birds with one stone...cleanup oversplash with kerosene...


Seriously. Long as you get it reasonably clean, and dry (dry is the key here...dirt and crud hold moisture, which when trapped under paint or undercoat will go NUTS rusting the metal...), then hit it with some good quality rubberized undercoat spray...one heavy coat...multiple coats tend to just wanna chunk off...

I see. So the old adage "do it once, do it right" definately applies here. So as long as I do a really good wash/dry before applying the undercoating, I should be okay, right?