Paint spec for renovated sash windows

[O'Chippy]

Interestingly you've discounted linseed paint which is the darling of the sash window brigade. Unfortunately no use in the coming months.
I feel if your definitely going to spray water based you need an air assisted airless set up. Anything else won't cut it as the temperature drops the viscosity increases making hvlp pretty useless. Even 5 stage.

Drying times of linseed paint are as I understand long, esp in winter, I dont have the time.
Plan is to use an airless set up, not sure if that presents the same issues regarding temp/viscosity.

 

[O'Chippy]

I don't think sash windows are a great subject for spraying. Lots of narrow pieces with big holes. And the paint ideally lips onto the glass over the seal which you can't realistically achieve.

Agreed they probably are not the best subject for spraying but I have seen them successfully sprayed before and they aren't that far off door frames and architraves which are commonly sprayed.

Good point on lipping the paint onto the glass.
I am aware of that technique and its benefits, I have in my mind to use Repair care putty alternative. Apparently it doesn't require to be painted over itself and I'm assuming by the nature of the material it wouldn't benifit from lipping paint over its junction with the glass.

 

[johnnyb]

Airless should work fine. It can be hard to control as to lose the horns you need a fair bit of pressure. Which results in lots of paint transfer!