Paint spec for renovated sash windows

[O'Chippy]

I have begun renovating many sash windows in a Victorian.
Existing paint and glazing has been removed, repairs are ongoing however I am a carpenter with little knowledge of paint and generally clueless on what finishing to use, either type or application/coats.

I've heard others argue both for and against the use of water based paints externally, a number swear only to use oil based.

The existing window joinery is largely (I believe) pine with a number of oak cills. Sash and box frame repairs will be made in accoya, cill repairs in sapele with Repaircare epoxy used where necessary.
I plan on using Repair Care Dry Seal MP, to putty in the glazing and I believe to will accept a range of paint finishes.

Given the time of year, a paint that offers quick drying time between coats would be favourable.
Also as I plan on delving into the world of spraying finishes on the interior carpentry I install, sprayed finishes are up for consideration.
I'm unsure which, if any, type of paint may tick those boxes so would really appreciate any opinions offered.


TIA

 

[meccarroll]

Hi I am also a Carpenter/Joiner...yes I hold carpentry and Joinery City and Guilds but am more proficient at site work.

I tend to use a mix of spirit based and water based paints for outdoor use. I will use a water based primer then overcoat with a spirit based topcoat. This has worked quite well in the past and tends to last about 8 years before I need to re-coat.

I have sprayed about 6 cars using cellulose paint which is a solvent based paint. You add a solvent thinner from a can to the paint and the paint dries as the solvent evaporated into the atmosphere. When spraying a car it takes a while for the solvent in the paint to evaporate so you normally apply several coats one over the other to build up the level of paint film required. You can buy Fast, Slow and anti bloom thinners for thinning cellulose paint. Cellulose thinned for spraying is fairly watery in consistency so you can use a smallish spray tip like a 1.3.

In the past, for kitchen cabinets and bedroom furniture I have sprayed acid catalyes paints. These paints are very different to cellulose in that they react with a catalist and chemically go off. They are touch dry in about 10 minutes and you can turn a cabinet door over and spray the other side in about 20-30 minutes. When I used acid catalyes paints I spray one piece at a time take it away from the spray area and then spray the next piece. I find this paint is best sprayed horizontally (lay the piece being sprayed flat) but it can be sprayed vertically to, with practice. If you try to spray too many pieces at once the overspray will land on the pieces that are chemically drying and stick to them making the finish like sandpaper. Acid cat paint often contains formaldehyde and a pungent thinner so care needs to be taken when spraying this type of paint. Both good filtered extraction (for the environment) and a very good face mask are needed for your own personal health. A/C paint gives good results that are hard wearing but does need a good setup for best results and heat too.

I am currently using water based spray paints which I have found dry rather slowly in comparison to the above so it's a new learning curve for me but less hazordous then acid catalyes paints. The water based primer that I am using has been taking around 1-2 hours to dry but thats probably because I did not use an additive to make the paint go off faster. The top coat dries in about 30 minutes but you need to take more care with water based paints as they stay soft longer than A/C paints and need to stay on a drying rack a lot longer before you can turn them to re-coat them. With the water based paints I sheet off the area I am spraying completly and add extraction to stop any overspray from entering the stacking area. I am also now using heat and exchanging the air in the drying area to help the drying process. I am going to look into water based paints in more depth in particular the additives for speeding up drying times and the water based paints that dry faster to. One thing to note about water based paints is they are thicker then A/C paints so you need a larger tip to spray them say a 1.8 to 2.5.

There are othe paints such as PU which are said to be very good at drying and hold a very tough finish but you need to be very careful about spraying most PU paints as they mostly contain isocyanate which can be very harmful to you and anyone that comes into contact with it. There are some PU paints that do not contain isocyanate but you need to be very careful in selecting a safe paint for youyou and your setup.

For spraying I would advise looking into spraying with a Turbine and HVLP spray gun or a compressor with a minimum 14 CFM of output and a HVLP spray gun. Good quality HVLP spray guns give reduced overspray so less paint is used on the panels you spray. The HVLP spray guns used with compressors generally need a mimimum of around 9.5-12.5 CFM for best results you probably need a compressor with a minimum of 14 cfm for constant results.

A good Turbine with HVLP spray gun will help reduce overspray and reduce paint usage so saves money on wasted paint.

 

[O'Chippy]

@meccarroll Thanks for the extensive response, certainly lots to consider.
ATM between this major renovation project and family life I have a lot on my plate and realistically won't be able to commit much brain power to in-depth learning of the various spraying options and considerations, from reading some of your posts and others there is much to consider.
For this particular project should I choose to spray the solution would have to be no more complex than >buy this tin of paint of the shelf>pour into this handheld sprayer>spray and walk away.
Completely understand that this particular strategy may be costlier and result in a lesser quality finish but life ATM dictates finding a method that gets the job done.

Have you any comment on the cordless Graco or Wagner cordless sprayer?
I'm on the DEwalt platform therefore as the Graco uses Dewalt batteries in amy be a good option but I its expensive and I cannot seem to find it sold as a bare unit.

 

[RobinBHM]

I plan on using Repair Care Dry Seal MP, to putty in the glazing and I believe to will accept a range of paint finishes.

have you any experience with using it?

I ask as it is not easy to use at all.

Ive done dozens of sashes with it and its pretty horrible to use -it is like trying to get a smooth finish with sticky decorators caulk

you might want to consider rapid set putty or normal putty.

 

[O'Chippy]

have you any experience with using it?

I ask as it is not easy to use at all.

Ive done dozens of sashes with it and its pretty horrible to use -it is like trying to get a smooth finish with sticky decorators caulk

you might want to consider rapid set putty or normal putty.

Haha, never used it but its promoted as being the opposite as you've experienced hence my consideration of it.
Actually I think its main selling point is it can be painted over soon after application, although
I unsure if in practice that is useful or not.

I've nothing against using putty, mostly because I have never used it before either.
I've never had great results with mastic so perhaps putty is the better option for me.
Great to hear feedback from actual users of these products in the field 👍

 

[deema]

Just from experience, I’ve found water based paint to be the stuff of the devil. It forms a hard shell that cracks, water gets under and rots the wood. First time you know is when a hole appears. You can’t burn / heat gun off, so your down to trying to sand back to bare wood. Oil based paint every day, or Linsead oil based paint (wrong time of year needs sun to harden and very slow drying).
I have HVLP but just started playing with airless. Finer finish with HVLP, but airless is far easier and perfect for finishing wood. You can spray anything straight out of the can without diluting with the right airless / air assisted airless. Not much overspray, in fact my very limited experience suggests less than my HVLP.

 

[meccarroll]

For this particular project should I choose to spray the solution would have to be no more complex than >buy this tin of paint of the shelf>pour into this handheld sprayer>spray and walk away.
Completely understand that this particular strategy may be costlier and result in a lesser quality finish but life ATM dictates finding a method that gets the job done.

Have you any comment on the cordless Graco or Wagner cordless sprayer?
I'm on the DEwalt platform therefore as the Graco uses Dewalt batteries in amy be a good option but I its expensive and I cannot seem to find it sold as a bare unit.

Ok, but when you start spraying if you don't take the time to prep the area, dust, spiders flies etc may land on your paintwork. If you do spray try to use a paint that has a relatively short drying time or use an additive to speed up the drying that way dust flies etc have less time to spoil your work.

I have not used any cordless paint sprayers but Graco and Wagner both have good reputations in the paint world. My HVLP spray gun is a Wagner gun and very good. Graco also produce some very high end HVLP guns too.

I would say the battery operated guns are more aimed for site use rather than mass spraying. If you buy a battery spray gun make sure it can use different sized tips for different paints or at least match the gun tip with your intended paint.

Solvent based paints are generally sprayed thinner than water based paints. Solvent around 1.3 and water based around 1.8 to 2.5. Check out the gun literature and make sure the gun can handle the paint you intend using.

I am not a paint sprayer or claim in any way to be an expert related to spraying but I have and do use spray equipment and the better you prep the work area, your equipment and plan ahead the better the results.

Buy some paint strainers for your paint, measuring cups, tack cloths and a gun filter for the paint these will help prevent contamination of the sprayed paint. Silverline Stearated Aluminium Oxide Rolls from ebay are good for sanding down and if you use them in a Makita palm sander can save a huge amount of time when sanding between coats. You can buy cheap paint strainers and measuring cups from Alixpress or ebay. Tack cloths help remove stubborn films of dust etc from after sanding and the gun paint strainer adds protection from particles in the paint landing on the finished surface.

 

[Jacob]

I've done acres of (single) glazing with ordinary linseed oil putty and once you've got the hang of it it's easy, a pleasure to use and very cheap.
Best to prime bare wood with knotting first, or old stuff including painted, with linseed oil.
Can be useful to soften putty with a quick blast in the microwave - just a few seconds.
Takes time to go off but can be painted once surface touch dry.
Lasts for 100 of years given good maintenance.
I got into linseed oil paints a few years back and now wouldn't use anything else for outside work. Expensive by the tin but but very good coverage and fast/easy to apply. Seems to stick to anything, bare wood, old paint, metalwork. It's very different from modern paints but fast and easy once you get used to it.
n.b. never use sprigs or pins except as temporary fixings if necessary - remove when putty has gone off enough, before finishing. No need for them at all on small panes.

 

[O'Chippy]

I've done acres of (single) glazing with ordinary linseed oil putty and once you've got the hang of it it's easy, a pleasure to use and very cheap.
Best to prime bare wood with knotting first, or old stuff including painted, with linseed oil.
Can be useful to soften putty with a quick blast in the microwave - just a few seconds.
Takes time to go off but can be painted once surface touch dry.
Lasts for 100 of years given good maintenance.
I got into linseed oil paints a few years back and now wouldn't use anything else for outside work. Expensive by the tin but but very good coverage and fast/easy to apply. Seems to stick to anything, bare wood, old paint, metalwork. It's very different from modern paints but fast and easy once you get used to it.
n.b. never use sprigs or pins except as temporary fixings if necessary - remove when putty has gone off enough, before finishing. No need for them at all on small panes.

Good to hear sprigs/pins are necessary, I have about 20+ panes of old thin glazing to refit and was concerned that at least one would suffer the wrath of the Estwing.

Yes I read that it is essential to prime bare wood prior to putty, otherwise the oil is drawn out of the putty and drys it perhaps?
Is there a specific linseed oil to use for this, would either boiled or raw versions suffice?