Pitch pine windows

[leucothea]

Hi!

I have some decades-old pitch pine windows in a much older house (1741) that are nicely made and in good condition. They are painted (on top of varnish) on the outside and varnished on the inside. I'm looking for some advice on how to renew/improve the finishes.

Outside, I'm interested in removing the paint and maybe linseed-oiling the frames for weather protection. However, I'm not sure whether this makes sense for pitch pine or whether they ought just to be painted? (I will do all this in the spring when I re-render the outside.)

Inside, I'm wondering whether to strip/sand and redo the varnish, but I'm unsure what varnish would be best or whether a finish such as linseed oil would be sensible/practical alternative? Or whether it's best just to varnish after a light sanding and thereby save a significant amount of work? I'm also unsure what material to use to renew the seals around the glass panes.

The photos attached are of the window that's in the worst condition.

Thanks in advance!

 

[leucothea]

Any random thoughts would be appreciated!

 

[Kearn]

Take a read here to get up to speed on linseed.

Brouns & Co Linseed Paint and Oil

We supply the highest quality, natural, solvent free linseed oil paint for interiors and exteriors.

linseedpaint.com

When done correctly, it’s great, but… you’ll find not all oils are equal. Exposure to sun predominantly, as well as the rest of the weather play their part too in degradation. The initial application is slow and repetitive and requires the right conditions. And you must get all wood back fully to bare wood which is probably the hardest part when talking about existing windows as the oil bonds with the timber.

As nice as pitch pine can be, most would argue it was never intended to be seen, so paint would have been the norm.

 

[leucothea]

That's a great link—thanks. I'll also take a look at his book.

It would certainly be a lot of work to get back to the bare wood... I did a test and there are two layers of modern paint on top of a dark varnish of some kind.

 

[Toby Newell]

Paint is best. Linseed oil as a finish is pretty rubbish. If you want to oil, use Tung oil. Although on pitch pine it might take several days to dry on the resinous late wood rings. That website is a bit romantically OTT. Linseed oil is a low quality finish and he is selling it at a big mark up. Linseed oil paints are simply old fashioned varnishes with pigment in them, better, but not great. Partially breathable but not as good as modern engineered systems like Sikkens. It is nice using traditional materials but a lot of piffle overstates how great they are. Shellac is amazing, I use hundreds of litres of it, but it's durability is pretty poor.

 

[Toby Newell]

Take a read here to get up to speed on linseed.

Brouns & Co Linseed Paint and Oil

We supply the highest quality, natural, solvent free linseed oil paint for interiors and exteriors.

linseedpaint.com

When done correctly, it’s great, but… you’ll find not all oils are equal. Exposure to sun predominantly, as well as the rest of the weather play their part too in degradation. The initial application is slow and repetitive and requires the right conditions. And you must get all wood back fully to bare wood which is probably the hardest part when talking about existing windows as the oil bonds with the timber.

As nice as pitch pine can be, most would argue it was never intended to be seen, so paint would have been the norm.

Mmmm. I am not most it seems. Not true I am afraid. Pitch pine I call an honourary hardwood. It was mostly polished or waxed and left natural as a show wood, for example, Westminister Abbey floor, 60 Carey Street (President of The Law Society) Pilkington St James Place office interiors all of which I have worked on and virtually every single church and rectory in the UK. It was very expensive, like Honduras mahogany, coming from limited size stock from a very limited area, ie a tiny strip of NE USA. It also doesn't take paints so well due to the high resin content, it was more often oiled, shellacked or waxed rather than painted. Painted pitch pine is often done after the fact. Pitch pine is rarer to find than oak (apart from Churches!) and was more expensive.

 

[Toby Newell]

Take a read here to get up to speed on linseed.

Brouns & Co Linseed Paint and Oil

We supply the highest quality, natural, solvent free linseed oil paint for interiors and exteriors.

linseedpaint.com

When done correctly, it’s great, but… you’ll find not all oils are equal. Exposure to sun predominantly, as well as the rest of the weather play their part too in degradation. The initial application is slow and repetitive and requires the right conditions. And you must get all wood back fully to bare wood which is probably the hardest part when talking about existing windows as the oil bonds with the timber.

As nice as pitch pine can be, most would argue it was never intended to be seen, so paint would have been the norm.

All finishes mechanically bond with the timber or they would flake off, hence the requirement for meticulous preparation. People like Rubio monocoat spout suprious woo woo implying molecular bonding, this is piffle. Oil penetrates deeper into the wood than most other non pressure applied coatings but this never cures, even after years, which is why oiled timber can affect adhesion of non oil based finishes even after stripping, chemical washing and sanding.

What you get is uncured oil soaked into a few microns in the wood which takes decades to oxidise, with a plastic polymeric film (exposed to fresh oxygen) on the surface. Linseed oil is pretty rubbish, weak, slow drying and rots. It was only used as a by product of the linen industry and thus very cheap. Before cotton most fabric and engineering textiles were made out of hemp or flax. Flake (lead carbonate) white and other metal salts were added to aid drying, improve adhesion, durability and speed up curing, ergo the birth of varnish. Boiling also partly preoxidised it and thus reduced the drying times, although as this traditionally took several days modern BLO is simply made by briefly heating with siccatives and adding driers like terebene.

Long oil or spar vanishes were basically mixtures of stand oil, which never fully dried and thus remained elastic, and rosin (the residue from pine turpentine distillation) called 'spar' varnish as was used to coat ship masts.

 

[Toby Newell]

I would run a boiling soda followed by boiling oxalic acid on your moldy windows, that will kill and clean it. Prep is 80% of the job, stripping is an art. I could teach someone how to finish much quicker than I could how to strip correctly. Linseed oil based finishes are very forgiving though.

For interior work you could try a traditional oil based varnish, one of the best being Mylands No 8 lacquer (it was good enough for The Sultan of Brunei) or a hardwax oil, the best being Bona Hardwax oil.

 

[Old School]

sorry not wishing to hijack this thread but our large front door which I am presuming is original or period will not take paint, I've now tried to re paint it three times despite stripping it back to bare wood and the paint just cracks the last time I used Bedec and that's cracked as well, I'm now thinking it's pitch pine and just wont 'hold' the paint, so would the best approach be to strip it back and apply some other finish...it's in quite an exposed setting and gets most of the weather..which in Cornwall is mostly wet. Any advice much appreciated.

 

[Toby Newell]

sorry not wishing to hijack this thread but our large front door which I am presuming is original or period will not take paint, I've now tried to re paint it three times despite stripping it back to bare wood and the paint just cracks the last time I used Bedec and that's cracked as well, I'm now thinking it's pitch pine and just wont 'hold' the paint, so would the best approach be to strip it back and apply some other finish...it's in quite an exposed setting and gets most of the weather..which in Cornwall is mostly wet. Any advice much appreciated.

Please send photos. Solvent borne PU is the most compatible, either white spirits based or xylene based, the xylene based is often two part but extremely difficult to apply by brush (designed for industrial use spray / roller coat / curtain coat) so a traditional yacht varnish, like from International might be your best bet.

Sometimes using a metalised aluminium primer helps. I did a door for a client which was normal yellow pine but the knots were very resinous, even though I used several coats of shellac knotting the resin still bled through.

 

[Toby Newell]

Fyi, many commercial non epoxy floor paints are two part isocyanate cured solvent borne PU, they have limited colours, like red, grey, blue but probably have a retarder to aid flowing so might be easier to apply.

Fyi I am a 30k hr / 30yr French polisher so I have studied finishes fir a few decades.

 

[Toby Newell]

sorry not wishing to hijack this thread but our large front door which I am presuming is original or period will not take paint, I've now tried to re paint it three times despite stripping it back to bare wood and the paint just cracks the last time I used Bedec and that's cracked as well, I'm now thinking it's pitch pine and just wont 'hold' the paint, so would the best approach be to strip it back and apply some other finish...it's in quite an exposed setting and gets most of the weather..which in Cornwall is mostly wet. Any advice much appreciated.

Do you have any photos stripped? So I can confirm if it is pitch pine? If not then just send photos of cracks.

 

[Old School]

thank you Toby I have followed your advice on here for a good while so I know that you really know your stuff, I've only just seen this but will take some photos of cracks tomorrow, when stripping the door it did seem quite resinous in places.
many thanks
Claire

 

[Toby Newell]

Do you know what the door was coated with the first time you stripped it?

 

[Old School]

No it had obvs been painted with blue gloss which had weathered to such an extent what remained looked like chalk paint.....house was a holiday home and pretty neglected...off out to take some photos will load up asap! Attached is the finish we inherited, not sure if you can see it close up enough to see it's been weathered through the top layer gloss.

 

[Old School]

A better one..

 

[Old School]

sorry photo dump of latest painting attempt Summer before last I think ....tried to show some areas with no paint, hope that helps, any advice gratefully received Toby, building is circa 1846 but no idea if door is original

 

[Old School]

last one..honest!

 

[leucothea]

Paint is best. Linseed oil as a finish is pretty rubbish. If you want to oil, use Tung oil. Although on pitch pine it might take several days to dry on the resinous late wood rings. That website is a bit romantically OTT. Linseed oil is a low quality finish and he is selling it at a big mark up. Linseed oil paints are simply old fashioned varnishes with pigment in them, better, but not great. Partially breathable but not as good as modern engineered systems like Sikkens. It is nice using traditional materials but a lot of piffle overstates how great they are. Shellac is amazing, I use hundreds of litres of it, but it's durability is pretty poor.

Thanks Toby.

Which Sikkens did you have in mind?

I'm considering Sikkens Rubbol XD Gloss. This is a nice high gloss and very durable, though not terribly breathable. However, seeing as these windows are set in lime-washed lime render, I don't know that any water is going to get trapped to cause issues.

 

[Kearn]

Thanks Toby.

Which Sikkens did you have in mind?

I'm considering Sikkens Rubbol XD Gloss. This is a nice high gloss and very durable, though not terribly breathable. However, seeing as these windows are set in lime-washed lime render, I don't know that any water is going to get trapped to cause issues.

I’ve not hear great success with Sikkens in the past (Satura). It started to lift and peel from timber in a few years.

Currently redoing a ton of windows of various timber, age and states of covering - using Sadolin Superdec.