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!

 

[markturner]

I would like to pitch in here, with both my experiences and some questions. I restored, repaired and redecorated all the sash windows in my grade 2 listed house around 4 years ago. I got all the sahes removed and dipped so started from scratch with bare wood. It took about a month to dry them all out, using a sealed room with dehumidifiers running non stop....I was keen to use traditional materials etc and so went with linseed oil paints by Brouns. I have had mixed results - it goes on lovely for sure, however, I have an ongoing problem with mould and dirt accumulating on the flat surfaces of the cills and mouldings. And when you clean the windows, paint dilutes with the water and goes all over the glass. I had some areas also where possibly I was geting bleed through of the dipping chemicals and other areas just seemed to never dry at all! And this is 4 years in!

I am going over them again starting this summer and have decided to use Dulux weathershield gloss instead. I did a test run on the porch and front door last year and the paint looks perfect a year on, which is more than can be said for the 2 or 3 windows I had to do some minor repairs and redceorating using the linsdeed oil paint ay the same time. We are slowly working round the house going over with weathershield Oil based. I notice no one who responded in the thread mentions using this at all? Just wondered why that may be? I found it very nice to use and very durable so far........

Currently I am also making some replacement sash windows for our neighbour, using sapele. I planned on using the same weathershield paint, but she wants me to use Farrow and Ball exterior paint. It is water based and I really dont like it so far, it seems very thin and I am dubious about it longevity......any users got any experience of this system here?

Because of my job and teh neighbours, I have been looking into the various options for paint and did come across a very complimentary long term test on YouTube, of the Treatex classic colour - this is also water based, but flexible and seemed good....again, any one used it?

 

[johnnyb]

I'm with you linseed paint is mostly hokum smoke and mirrors. But it must have something to recommend it. Dulux weathershield I have found to be a good paint albeit trickier to use than some(it needs thinning in trade guise and tends to rapidly skin as its got lots of driers) me and another(fairly experienced guy) both used weathershield. How linseed ever got any traction is hard to say. It's like the emporers new clothes. Zinc oxide stops mould growth they say. Not in my experience. Only lead tetroxide. The op seems like he's decided to spray water based and avoid all trad materials and I hope that approach works out but you raise another point about contamination which is a known issue with water based coatings. I swear 120 year old paint is almost unaffected by stripper but will burn off. Of course caustic can have its own issues as well. It often denatures the wood meaning some bits can almost reject coatings. I'm not really keen on any plastics in contact with old wood ? Caulk,foam ,it all traps water. Especially at the bottom of stuff(say the front linings or under the sill(

 

[johnnyb]

I've worked on enough old timber to know using normal trad materials they can last just fine. But neglect and poor water management(dodgy gutters) can leave them in such a state its hard to know what to do....it must be the paint/putty/wood etc. Then the inevitable upgrades start linseed paint, accoya, heritage putty, spray paint etc. Some may be improvements but which ones. Better to fix the roof gutters drains and passively protect stuff if possible than open a new can of worms.