Warranty issues you'd think

[GTyankee]

People that are in the under coating business, say that that heavy black spray is good until water begins getting into the cracks, then that heavy black spray begins to lift away from the metal & rust sets in.

The people that use Krown & similar products don't complain about it, BUT unfortunately, some mechanics do not like to work on a vehicle with it.
The stuff rubs off on them.

 

[62Blazer]

People that are in the under coating business, say that that heavy black spray is good until water begins getting into the cracks, then that heavy black spray begins to lift away from the metal & rust sets in.

The people that use Krown & similar products don't complain about it, BUT unfortunately, some mechanics do not like to work on a vehicle with it.
The stuff rubs off on them.

Guess I understand where they are coming from. From my personal experience I think the thick rubberized undercoating makes it a pain to work on vehicles also. All of the bolts and nuts are coated in the stuff and you have to scrap it off first, which also makes a mess. The oil/wax based stuff you don't have to clean it off first, but if you do it only takes a can of Brake Cleaner and a rag. Much rather deal with a little oil based undercoating then rusted up parts!