I have started using Dynotrol in the past year based on a recommendation from
someone on this list. They have a lot of different products because different
OEMs have a slightly different expectation. Since they are an OEM supplier I
expect their products to be as advertised. For a number or their undercoating
formulas they state the number of salt spray hours that a given coating passed.
Several of their products passed 1000+ hrs. For reference the underbody paint
spec (for suspension control arms, etc.) on most domestic cars is 336 hrs.
Other options are to buy undercoating from your local automotive paint supply
store (assume a jobber that carries 3M products would have a quality
undercoating). Prior to undercoating I would remove the loose rust using a
wire brush or other mechanical means and apply a phosphoric acid rust treatment
to convert the existing rust. On this treated surface I would apply a good
anti-rust primer. I'm partial to PPG's two part epoxy primer but it is rather
expensive and is really bad to inhale (carcinogenic). Alternative primers such
as POR-15 (which I have not used), Eastwoods Corroless (sp?) which looks, smells
and cleans up just like Rustoleum's rusty metal primer along with the just
mentioned Rustoleum primer would be a good finish between the rust treatment and
the undercoating.
......Are there any undercoatings
that the list has had an especially good experience with? Also, what is
the recommended remedy to treat surface rust? POR 15? A rust
neutralizer?......
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