"Robert11" wrote in message
news
Are there general rules of thumb for when, and where, paint primer should
be
used before applying the regular paint ?
Interested in both interior and exterior.

You need only think why primer is used -- in order
to make the colour coat cover better and adhere
better than it would if you used no primer. So the
rule of thumb is that you should always use a primer
unless you know there is no need: always prime
unpainted wood, prime when you plan to cover
a latex with an oil paint and vice versa.

--
Don Phillipson
Carlsbad Springs
(Ottawa, Canada)