Doug Miller wrote:
Norminn wrote:
Doug Miller wrote:
Norminn wrote:

You don't normally need to prime a wall that is already painted.

Not normally, but in a case such as this -- where he's painting over a color
that will be difficult to hide -- a tinted stain-blocking primer can be a
great help.

Primers have a lot less hiding power than paint. Why would you prime
and paint when two coats of paint would cover better?

You're missing the point. Two finish coats is a given anyway. The question is
one coat of tinted blocking primer plus two finish coats, vs. three finish
coats.

I don't know if it's automatically a three coat job. Two finish coats
should cover. If it's not, either the paint is a low solids cheapo
brand or it's being put on too thinly.

There are other reasons to omit the primer entirely. Leftover tinted
primer is pretty much useless, whereas leftover finish paint is very
useful. There's also the Murphy's Law factor - you'll either have too
much leftover primer _and_ finish paint left over, or you'll run short.
The first case gives the OP inventory - not really a benefit, and the
second case costs her more for the expensive finish paint. The most
economical way to maximize the materials cost is to use the same color
finish paint on two coats for the three rooms and skip the primer.

R