i've read reports and heard many radio talk shows that say krown has one of the better products. from what i understand its not the outside visible rust that is the concern. in fact if there's rust on the outside then most surely its worse inside the panels. if there is hidden rust then it is supposed to slow the process down markedly. they even claim the product prevents electrical troubles (?) perhaps by eliminating water. spring (ie now) is supposed to be the best time to apply to get rid of winter salt. besides it's only $110 ($100 on sale) and doesn't appear to do any harm.
my $0.02.
karl
