The west side doesn't have a roof overhang nor gutters (since the overhangs are on the N/S side). Inclement weather hits the west side of the house the most (at least the shakes are asbestos, so that's a relief, toxicity issues notwithstanding.)

The newly retrofitted sliders had been inset into raw wood framing, via gas-operated nailer.

Here's pic of the exterior of one of the western ones:
See the raw wood facing the west?

Questions:

Firstly, do I need to paint ASAP - or is there a grace period of weeks, or months, or years to get the framing painted?

Secondly, I have Ben Moore Premium Interior Latex paint [pearl color] in the house. It's difficult to get to the home center 1/2 hour away. I don't have a car, the transportation system is horrible, etc.

Would the premium paint intended for interior, passably protect the outside raw wood?

Finally, i'd appreciate an online pic showing the best paintbrush for this? (I have plenty of brushes in the house, both bristle & foam ones. Just wanting to know which is optimal for such a job).

Thanks!

And should i rush to do it?

and which brushes?

btw, do i need to bother to do anything with the peeling framing that you see surrounding the current raw-wood frame?
...or is that OK left alone, the way its been for decades?
(i'm not concerned with beauty, rather just maintenance, since this house is basically a junk heap anyway.

Should it be a 2" wide or 1" brush?

Any comments on that?

Also, I have (out in the freezing garage) some cans of varnish, and some Val-Oil
...it's from long, long ago.

I believe one of them is Man O'War varnish.
Would any of those be OK to use?

I remember decades ago, attempting to varnish a picnic table outdoors in the hot sun, and it started emitting smoke, so i was terrified. That was old stuff too.

NO,no,no

You can use any brush size because it can be turned sideways for such a small job but obviously the smaller ones are cheaper and slower to use.

Do not expect paint to seal exterior cracks or joints; it will fail and water is drawn into a wall through tight cracks as if it were under pressure. The detail you show needs trim that is sealed to the window frame and wall, then paint so whatever you use now is only temporary. Why do something more than once? It's always cheaper and easier to fix it right the first time.

Dare I tell you that there are low temperature paints that can be used as low as 35 degrees (that is the lowest overnight temperature not the daytime temperature). Such paints are usually only sold by professional supply houses.

So - to ensure we're on the same track - the correct answer is to wait until spring time, and then apply ONE COAT PER WINDOW of latex primer, using a one inch angled brush

So would I need a gallon? (for 4 wide windows)
Maybe something similar to either of the below?
KILZ:
http://www.homedepot.com/h_d1/N-5yc1vZ12ky/R-202017427/h_d2/ProductDis play?langId=-1&storeId=10051&catalogId=10053

BEHR:
http://www.homedepot.com/h_d1/N-5yc1vZ12ky/R-100205766/h_d2/ProductDis play?langId=-1&storeId=10051&catalogId=10053

With all due respect, you should get estimates from a reputable handyman in your area. You will be money ahead in the long run but only if you seek out those with experience and have a good reputation in your area. Ask neighbors, friends, family for reliable, reputable help that they have used in the past and are satisfied with their work. Windows need to be flashed right in order to keep water intrusion/ moisture from gettin in. The caulking is only for cosmetic purposes only. Get someone that knows what they are doing or you will only have continous problems and you will constantly have to re-do your work.

First of all - graywings, thanks so much for all your helpful tips.

To Sierraeast, and anyone else:

Can you please give me a ballpark figure as to what it should cost to get 4 of those windows attended to by a licensed painter?

I've never done this before, so have no idea.
Thanks again!

Painters in many places just operate as a general contractor.

There is typically no license just for painting like plumbing or electrical licensing.

ook for bonded and insured.

to diy:
scrape or sand excess paint off surfaces where
screen was..is that what the dark areas are?

caulk any holes, and where new trim pieces meet
in corners. cut just the tip off the caulk to
use a small bead, and use your finger to push it
into the cuts, holes & gaps. (but not weep holes in windows)
keep a wet rag handy to clean your fingers.
caulk is about $5 a tube and an inexpensive easy
to use caulk gun is about the same...but make
sure it has the attachment to puncture the
inner liner in tube of caulk.

use an exterior window and door caulk white or clear
with a long life 35 to 50 years.

give caulk 24 hours to dry.

make sure all surfaces to paint are clean and dry.
prime..I did 2 coats of water based kilts. if
wood is really dry and kiltz is absorbed you may
need to add another coat of kiltz.

let the kiltz dry..at least 24 hours.

then paint with exterior trim paint.

let first coat dry and paint again.

I'm a Behr paint girl..but any good
paint will last as long as you have
prepped well.

don't store paints & kiltz where they
will freeze, as they won't be good
later when you go to use them.

best of luck.

He said the job should wait until at least March.

Here's the sequence he quoted he'd do (I didn't prompt him with suggestions, rather waited to hear his proposal):
(1) scrape old frames
(2) caulk cracks between old & new frame
(3) primer on the new wood
(4) 2 coats of exterior paint

Four windows for $200.
I'm leaning toward using him for the job. We'll see, come March, taking the mercurial times we're living into consideration ;-)

P.S. curious why you state primer should be applied before caulk, whereas he does the caulk first.. He's an older guy, maybe in his 60's and seemed quite experienced.

There wasn't seepage that I know of, but then again, they were very old windows, including storm windows. If anything, the sloped-wide windowsill between the inner 1950s window and the storm window might have sometimes been damp if I'd forget to close the storm window when it rained.

Nothing too bad that couldn't be mopped up.