[x711]

First my observations on primer and then a couple of general questions.

Looking at the various information about primer I have noticed one constant
that is typical of most posts. People that use a epoxy based primer direct to metal or over a scuffed substrate typically cover it with a 2k based primer and in some cases a sealer after the 2k primer.

So we would have a typical Layer build as follows.

1 Metal substrate or scuffed paint
2 Epoxy Primer
3 2k primer.
4 Thin Sealer coat "Sometime"

Ok to my questions.

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1 Why do most people surface the epoxy based primer with a 2K based
primer.

2 Is the sealer coat used to provide "only" a very smooth finish to paint on,
or does it inhibit moisture from getting to the 2k primer underneath.

3 Is there an advantage to applying a 2K primer over the Epoxy primer.
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Thanks for your insight X711

[baddbob]

Originally Posted by x711

================================================== =====
1 Why do most people surface the epoxy based primer with a 2K based
primer.

2 Is the sealer coat used to provide "only" a very smooth finish to paint on,
or does it inhibit moisture from getting to the 2k primer underneath.

3 Is there an advantage to applying a 2K primer over the Epoxy primer.
================================================== =====

Answer to 1-- 2K surfacers are designed for filling and sand much easier than epoxy

2-- A sealer is used for a couple of reasons, to color the car with a shade that makes for better coverage, and to seal the substrate to the solvents from your topcoats don't get sucked in. Some 2K surfacers suck up solvent like a sponge.

3-- sandability



I usually don't use a sealer, the urethane surfacers I use for the final sanding work just fine. Epoxy does work well for a sealer but it shouldn't be applied very thick, needs plenty of flash time-overnight is best but not longer than it's recoat window unless you plan to sand and scuff. JMO