m Ransley wrote:
Some oils yellowed but a warning unless you clean the trim and sand it
real well, it is likely never to bond right, many times ive seen latex
over a hard oil trim that came off with your fingernail. If it is a
quality old smooth finish then only oil can get that again, Penetrol in
oil or Floetrol in latex help, both made by Flood. The smoothest
finishing paint is Benjamin Moore satin Impervo, expensive but the new
formulations dont yellow as much . Latex may be easier now but dries to
quick to level and get real smooth, and bonding issues can make
stripping it off in a few years necessary, unless you spend alot to
prep.

Prep doesn't take a lot of time, depending on
whether the door is flat or a panel door. One
just needs to do it right. Wash with Trisodium
phosphate (or maybe a substitute), wet sand with
220-400 grit wet or dry paper and rinse off.
Don't need to sand a lot, just keep washing the
paper so that paint doesn't accumulate on the
paper. Maybe a lot of time if one is impatient
and thinks that 15 minutes per door is a lot of time.