Undercoating is used for 2 reasons. The obvious one, to try to prevent premature rustouts, and the other less obvious is for sound control. It adds mass to the panel and helps to prevent "drumming" while reducing the passage of sound. Like adding Dynamat. Anyway undercoating does help to lengthen the time required for the car to dissolve. The probelm is nothing lasts forever. Eventually the undercoating dries out, cracks, and moisture penetrates it to the base metal. Now it traps the moisture and hides the damage until it is so bad the undercoating comes off in chunks, like the epoxy paint. There is no magic system that will last forever if you have mild steel underneath. This is probably one of the reasons JZD had the molded frame in mind origionally. He understood why cars wear out and was trying to make a car that could last so long the owner would get tired of it before it wore out. In that case you would go in for a "panel job". In one day they would replace all the exterior panels for a different color. Look at what happend to domestic cars produced in the early 70's. Most had NO undercoating and many just rotted out so bad you could see right through the fenders to the ground and all around the wheel wells. The first big improvement was when the automakers went to "Galvaneil". It was mild steel coated on one side with zinc. That helped but the biggest improvement was when they started dipping the cars and "electrocoated" them. That gets the zinc into all the hidden spaces after all the welding. Undercoating is still used, just a lot more sparingly. It adds weight which hurts fuel economy. On most cars now the wheel wells are now plastic. Lighter and doesn't rot. The holy grail now among automakers is to reduce the amount of steel and use lighter composite or plastic parts. GEE, JZD did that over 20 years ago. I guess he was on to something, it was just that materiels science was not up to the task at the time. David Teitelbaum vin 10757 --- In dmcnews@xxxxxxxxxxxxxxx, "content22207" <brobertson@xxxx> wrote: > CLEANING the undercoating? You obviously have more spare time than I. > > I own 5 Lincoln Mark V's. 4 of them came from the Northeast. 2 of them > were undercoated with that black mess people use up there. Both of the > undercoated cars suffered more road salt damage than the cars that > were left without it: > To address comments privately to the moderating team, please address: moderators@xxxxxxxxxxx For more info on the list, tech articles, cars for sale see www.dmcnews.com To search the archives or view files, log in at http://groups.yahoo.com/group/dmcnews Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/dmcnews/ <*> To unsubscribe from this group, send an email to: dmcnews-unsubscribe@xxxxxxxxxxxxxxx <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/