Protecting new window cill before painting

[TheSpid]

Hi there all, we have had new wooden window cills to replace the rotten ones. Lovely French oak - they look lovely but are untreated in any way. There is more work to do on the windows in the next couple of months and then I will be painting in Linseed oil paint when the weather is warm enough to do so. So how to protect the oak until then? I have it in my mind that linseed oil itself will be enough. Can I paint over that later though?

 

[Feltwell]

If you're using linseed oil paint then yes, you can paint over linseed oil treated timber with no problem.

In fact the Holkhams (Alback) paint recommended that bare timber was first painted with heated linseed oil before the first coat of paint went on - or cold linseed oil be applied then heated with a hot air gun to help it penetrate.

For a short while of a few months you'll be fine I reckon. Just don't forget that when you do come to paint you must paint in very thin coats - if you think you're painting it on too thinly, you're doing it right!

Personally, I've fallen out of love with linseed paints, but that's another story.

 

[TheSpid]

I'd like to know the story if possible? Is there a good alternative?

 

[Feltwell]

The theory of linseed paint is great I think, and it is lovely stuff to work with, but I've found it's just not durable enough, on horizontal surfaces especially - and it can be prone to mould growth. New driveway gates that I painted about 5 years ago with Holkhams (Alback) look shocking now, the paint on the top surface especially has had it and is disintegrating. Similarly on the house, fascia boards painted 10 years ago still look good - they are of course vertical and relatively sheltered - but window cills were stained and a bit grotty looking within a couple of years, and couldn't be cleaned up. That was on a relatively pale colour, buttermilk.

But - the main issue is the drying time. Trying to restore sash windows was just a nightmare, linseed paint takes so long to dry and needs so many coats. Makes it very difficult decorating outside as well, in our lovely British weather.

I've switched now to microporous water based paints, Bedec MSP in my case. I only switched about 3 years ago, but there are plenty of reports out there of them being very durable and giving a long service life - you don't seem to get the cracking and failure that happens with the usual Dulux-type impermeable paints, as the microporous ones have that element of breathability. There are a few other fans of this type of paint on this forum.

The caveat is if you like very glossy paint finishes, you'll still get a higher gloss with less brush marks if you use solvent based paints. If you're not fussed about high gloss (I go for satin finishes deliberately - I prefer them) then water based is fine, and they do do a gloss, it's just not as glossy as solvent based. It's also much quicker to dry, much easier to clean your brushes up, and environmentally better. Only drawback is you're not supposed to paint outside if it's below 10 degrees, although by being sensible and painting at the start of the day so it's got time to dry before the night time temperatures hit, I've got away with painting at the lower temperatures around this time of year.

I like the Bedec paint - they are a very small manufacturer so you may find it easier to buy online, but there are a few Decorator's merchants who stock it. I buy mine from Promain:-

https://www.promain.co.uk/multi-surface-paint-msp-1173.html

Don't whatever you do put linseed oil on if you are thinking of using water based paint - the Bedec would go over it eventually but only after a long period of weathering and absorption.

 

[88v8]

For similar reasons I too have gone off linseed.
Other than on the hottest day, the drying time is impossible.

And in damp conditions it supports mould.
We had some new windows made, I intended a variety of finishes including linseed so some of them were primed with a 50/50 of boiled linseed oil and turps. It was months before I got round to installing them so the primer was well dry, but internally where other jobs have intervened so they are still in primer, they are supporting varied colonies of moulds.

I think linseed has its uses. Outside, south facing only, the ability to paint in full sun is valuable, and the flexibility and long life then comes to the fore. It is particularly valuable in dark colours which are otherwise a no-no on a south facing due to thermal gain. Our linseeded black garage doors show no signs of paint distress. East, west, north, forget it. And internally I think it's quite pointless.

Oak does not care for being painted. The grains is quite mobile and throws paint off. If I were trying to keep paint on oak, I would prime with .... 50/50 boiled linseed/turpentine so the wood soaks it up, then when dry I'd use the Bedec stain blocker, two coats, and Bedec MSP.

Internally I prefer oil, usually AZ Rubbol although internally just about any decent oil will do.

Ivor

 

[Flyfisher]

The exterior of our house is a mix of plain limewash walls and black doors and windows. Black is a terrible colour at the best of times but on south and east facing walls the sun is very hard to protect against. When we first moved in I painted a number of windows with Sadolin, but after about five years it was flaking off. I then replaced a few windows and used black linseed paint and that has lasted much better than the Sadolin. I painted a new north facing external door and window with (shock, horror!) Dulux exterior black, after first painting the bare hardwood with aluminium primer and then Dulux undercoat. After 10 years, the paintwork is still in good condition. On our west-facing kitchen extension, we had oak windows and door fitted and I just covered these with one coat of interior Osmo polyx with the intention of letting them gradually weather naturally, but the soffit and bargeboards I painted with black linseed paint and these still look good after about six years.

I can honestly say I've not had any mould problems with linseed paint, but would agree that it's not the easiest stuff to use - not in the application but in the drying time, which is ok if you're happy to leave windows and doors open for a few days but hardly ideal!

My dilemma now is that I had three new hardwood casement windows made last year but did not get around to fitting them, so that'll be a job for this year when the weather improves. They will be south-facing, so what should I paint them with - linseed (because the drying time is less of an issue if painted before fitting) or the Bedec MSP I've been reading good things about?

Personally, I'm beginning to think that the most cost-effective solution would be to fit solid oak windows and doors andjust leave them to the mercy of the elements! It wouldn't be cheap up-front but whoever is living with them in a couple of hundred years time would likely be very pleased with their low-maintenance costs. Of course, from an aesthetic perspective, plain oak windows would not suit all properties but just think about how much simpler property maintenance would be if we didn't have to paint everything.

 

[TheSpid]

All very interesting - thank you.

I would love to leave the oak but the rest of the windows are painted, and the repairs will be in oak but in the painted sections. The original wood is very well season old pine and the carpenter said it was in fab condition in general so no need to replace - so I feel in this instance I need to paint in some way, as otherwise it's going to be a hotch potch of finishes.

I will leave it to the elements for now and research other paints. I have to admit the drying time of linseed did worry me - especially in rainy Wales.

 

[Craig89]

I have just spent £375 for 20 litres of Bedec MSP for my new windows, that are currently being made, on the recommendation from people on this site. Im getting it via my local Brewers (which I believe is a national decorators centre). Bedec are mixing it in Farrow and Ball colours for me. It is a lot of money but if it has as much durability as is claimed then its a small price to pay.

 

[88v8]

Yes, I hope it matches the hype.

As a recent adopter of water-based paint, I may be telling granny how to suck eggs, but....
- it works best with a synthetic brush
= don't let the paint dry on the brush. For example, if you're using two different brushes concurrently such as a fitch and a 1".
Once the paint dries you can't get it off the brush. So you may need to wash the brushes out periodically as you work. No need to dry them.
- do follow the usual good practice of rubbing down between coats.
- observe the temperature and humidity limitations. Min temp 46F and max humidity 80%, during application and drying.
The Met Office website currently shows humidity which makes it useful for planning one's decorating schedule
https://www.metoffice.gov.uk/public/weather/forecast/gcnx0z9e5#?date=2019-01-15
but their retrograde beta version does not. The beta version is sometimes available, and when it is, you may wish to bring this deficiency to their attention.

Let's hope that in five years or so we can begin to report the ongoing durability of MSP.

Ivor

 

[Feltwell]

If I were trying to keep paint on oak, I would prime with .... 50/50 boiled linseed/turpentine so the wood soaks it up, then when dry I'd use the Bedec stain blocker, two coats, and Bedec MSP.

I wouldn't put anything oily on before anything water based Ivor. I had issues with using MSP over linseed putty, even after a few months - I've now switched to a putty alternative. Bedec themselves say " Substrates which have had water-repellent preservative treatments applied should be avoided because adhesion could be compromised". I thin the first coat of MSP with water to help it prime better, which was the advice on the tin.

 

[malcolm]

I'm still delighted by linseed paint and putty and use them onto everything, even aluminium guttering. The advantage for me is the failure mode - it goes matt and dusts rather than cracks so is easier to paint over again the next time, and I'm sure linseed is the main reason we still have 200 year old windows knocking around. It went out of fashion because of the painful drying times. I would avoid suppliers that have tried to reinvent the paint, instead use those who import from countries that never stopped using it.

Modern oil paints will crack and trap water (and need stripping every repaint) so few on here will recommend them. I must defer to the those who have tried modern water based paints. Never used them myself.

 

[88v8]

I wouldn't put anything oily on before anything water based Ivor. I had issues with using MSP over linseed putty, even after a few months -

Agreed. But Bedec's stain blocker is designed to deal with that situation. Or so it says on the tin, and I jolly well hope it will

Ivor

 

[plasticpigeon]

I'd have thought that one of the big chemical companies could make a linseed paint that dries in reasonable time. All the old books I have say that driers can be added to linseed paint so perhaps that is the answer. I'm sure the Victorians and Edwardians throwing up row and rows of terraces and semis didn't want to wait 2 weeks for paint to dry either. I haven't used it because it is not very available and is expensive. However I just bought 5 litres of Dulux solvent based gloss and it was over £80 from the Dulux decorator centre, so perhaps cost isn't so prohibitive these days. Unfortunately I have painted my house with modern paint and I'll be damned if I'm stripping it all again.Perhaps I'll do linseed at the next big repaint.