Re: polishing paint?

["Greg Herrmann" <airtech@isoc.net>]

>There are actually quite a few cars on the market that don't have
>clearcoats.  In fact, most die-hard autobody/finishing pros will tell you
>that clearcoats are the inferior finish.  Clearcoats are achieved by
>spraying a very thin layer of pigment over the sheetmetal, just enough to
>cover, then several coats of urethane are sprayed over the matte pigment to
>create a gloss effect and complete the finish.  It's a quicker, cheaper
>finish than multiple coats of pigment filled lacquer.

Quicker yes, cheaper.....not even close!   The overall cost of urehtane
base/clear is cheaper because of the labor involved with a lacquer paint job
(color coat, color sand,color coat color sand....etc), but the cost of
material for urethane is about 5 times as much as lacquer.  To acheive depth
in lacquer, it still needs to be clearcoated, color sanded and buffed.



  The pigments are the
>most expensive component of the paint and their proportion, purity and
>consistency must be exact.  One thin coat of pigment is easier to manage
>than several pigment filled coats of lacquer.
>
>The clearcoat, or base/clear, finish is a compromise in several regards.
>Urethane clear dries VERY hard.  Same stuff is marketed as "Hard as Nails"
>clear for furniture and such.  Turns out to be both a PRO and a CON.
>Because the urethane is SO hard, regular buffing and compounding is much
>more difficult.  The clear is so hard, that it is resistant to being
>smoothed and buffed flat again.  You often have to use a much more abrasive
>compound to achieve the desired result, ultimately removing more clear.

Regular buffing and compounding is not needed because it is so hard.  Once
the finish is flat, the finish is flat.  Urethane's resistance to scratching
and oxidation is so far superior to lacquer that regular buffing is not
needed.  You only need to remove as much material as is necessary to get the
finish flat.

 In
>many instances, deep scratches simply cannot be safely removed.  If you cut
>through the clear to the pigment, your finish is ruined.  The finish
"gurus"
>I've talked to have all said that a non-metallic lacquer finish is the "car
>lovers" finish, and the clearcoat is the "wash-and-wear" finish.  Due to
>oxidation, lacquer requires extra waxing, and rubbing and such, but the end
>result is usually a deeper, richer finish.  Metallic paints are a different
>story because non-clear metallics have a nasty tendency to bake and dry,
>giving the chalky matte metallic look.  If properly maintained, either
>finish (clear, lacquer) will provide year after year of eye pleasing
>protection.   The secret is not "letting it go".
>
>PS - before someone gets on me - there's also an Acrylic Enamel, an
>amalgamation of the clear and lacquer.  Pigment paint with urethane
>hardness.  Consider it somewhere between the two.

Acrylic enamel is just another type of paint.  It cures through a chemical
process just like urethane,  but is far less durable.  Lacquer doesn't
really cure, it dries thruogh the evaporation of the solvents in it.
Urethane is not synonimous with base/clear either.  You can get urethane in
a single stage system also, just as you can get lacquer in base/clear.

Greg Herrmann