How to get external windows back to bare wood....?

[Krome10]

Hi all

I want to get my wooden windows sorted before winter reaches us.... I'm not sure what's on them at the moment, whether it's paint, varnish or woodstain. But it is peeling/flaking off in places.

Is there a best method for removing and getting them back to bare wood? Would heat guns/paint stripper goo potentially damage the seals or damage the windows in any other way? And if so, what other options are there?

We want them back to bare wood because we then hope to treat them with something that will maintain their woody appearance...

Many thanks

Max

 

[Krome10]

Hi guys

A bit of an update and addition....

If we cannot get it to bare wood sufficiently, or if the bare wood looks crap, then we are going to look to paint them. But if painting, do we still want to get rid of as much existing paint/stain as possible?

I've been told in the past that it is best to use paints that allow the wood/windows to breathe. Would you guys agree? And if so, how much does the removing process effect the wood's ability to breathe?

Cheers

Max

 

[Jacob]

I'd only remove loose stuff - with a scraper, wire brush, and sandpaper to flatten and key in the paint. Then linseed oil, which sticks everything down really well, then oil paint. This is the Holkham Paint way, which I've been using a lot and is better than any modern paints, in terms of durability at least. It's particularly good covering failed modern painted surfaces as long as they were oil based. Most of them are.
Paint "breathing" is just advertising hype. All paints are porous.

PS the last thing you want is "a woody appearance" - everything needs to be well covered in paint or oil.

 

[Krome10]

Thanks for that. Funnily enough, I was just reading about Holkham paints (and Holkham is just up the road fro me)....

It does sound good, but my reservations are:

- Their website says that for the paint to achieve the results they claim, the timber would need to be back to bare... It suggests that the paint (or any paint) is only as good as what is beneath. I'll find the quotes if that wold be helpful.

- It worried me that you have to wait so long between coats (sometimes a week or more). That would take us well into autumn.

- The site says “Linseed Oil Paint is not recommended for use on Pressure Treated timber.” I'm not sure how I can tell whether my windows were made from pressure treated timber....

 

[Jacob]

It works really well without going back to bare wood - in my experiments at least. Yes paint is only as good as what is underneath - but if what is underneath is stuck down well, then that's fine.
Slow drying but only a day or so. It works OK in Autumn too.
I don't know about pressure teated wood problems.
Nearly 4 years experiment here: http://www.woodworkuk.co.uk/forum/viewt ... 8&start=40

 

[Krome10]

Thanks Jacob - much appreciated.

RE: underneath. As I read and understood it, the linseed based paint is effective because it penetrates and soaks into the wood; as opposed to some/most paints which sit on top of it and form a seal. And that seems to be why they say it will not be nearly as effective applied on top of old paint..... It cannot get into the wood.... Worse still (their site suggests) is when the wood is partly bear and partly painted, as it will penetrate in some areas and not others, which could lead to different finishing results in those areas.

Interesting that these things have not been the case in your experiences though....

 

[Jacob]

The way I see it is that if the old paint is well stuck you can leave it alone and the oil will flow around it into the bare wood as well as dry onto the old paint.
Seems to work on that board door in the other thread. The finish with linseed oil paint won't be as good as many modern paints, but the main thing you want is for it to stay in place, which is where linseed beats modern paints.
Colour density and cover is also very good.

 

[JakeS]

I'm not sure how I can tell whether my windows were made from pressure treated timber....

As I understand it, the whole point of pressure-treating timber is that then you don't need to paint it; and the problem with painting it is that the stuff they pressure-treat it with slowly seeps out of the wood. So my guess would be that if the windows are currently painted, they probably aren't pressure-treated timber!

Modern pressure treatment involves copper, I believe, and the wood tends to look a bit off-colour and ill - our picnic table even has what looks like copper salts forming around the knots and so on. I seem to recall reading that the pressure-treatment industry moved to a copper-based treatment from something else about a decade or so ago, though, so maybe that doesn't stand for older stuff.

 

[marcus]

+1 to Holkham - lovely stuff. They sell special round brushes to apply it and it's worth getting a couple - they work much better than normal brushes with it.

 

[wobblycogs]

On windows I'd go with Jacobs advice of just removing all the loose paint (scraper, wire brush) and then painting over after a good keying in with sand paper. Be fairly aggressive when removing the old paint as you don't want anything that might lift / flake a year from now or you'll be back to square one.

If you do want to get back to wood your two options (realistically) are a hot air gun or paint stripper. If you want a wood finish e.g. varnished, then you'll have to go with paint stripper as you will char the wood in places if you use a hot air gun. If your plan is to paint the windows after stripping them then go with a hot air gun as they are much faster, cleaner and less likely to cause you to become sensitized to the chemicals in paint stripper (sensitivity to dichloromethane is not pleasant, take it from me). The only problem with a hot air gun is you can crack the glass in the window if you aren't careful. My hot air gun comes with an adaptor that is used to direct the air away from the pane, it seems to be fairly good at what it does.

 

[AndyT]

+1 to what Wobblycogs said. I recently overhauled our 100 year old sash windows which had not been touched for 20 years or so. I took the sashes out onto a Workmate and used a hot air stripper on the internal, moulded surfaces, and across the flat outside surfaces, with a 2" flat paint scraper to lift off all the old layers of paint in one go. The flat surfaces then got a quick going over with a small random orbit sander, and a delta sander on the awkward bits. I could remove, strip and prime a pair of sashes, then re-hang them with new cords and beading, in a working day - and I'm not a very quick worker.
If I had been hanging about waiting for paint remover to work I don't think I would have finished!

I'd always paint wooden windows unless you have something seriously historic and listed. There is one house in our street where they have replaced white timber with dark brown upvc, and although the sections are fairly slim, the whole appearance of the house front just looks so wrong - the windows disappear into the shadows.

 

[Krome10]

Thanks for all the input guys.

I've decided against the bare wood idea now and will definitely be painting. I'm looking at the following paints at the moment and any thoughts from people who have used them would be great:

- Marston and Langinger
- Beckers (from Sweden)
- Sadolin Superdec (with Zinsser 1-2-3 as primer).

It's interesting what was said above about sanding. I've been asking about and there seems to be real mixed opinions. Some say just give them a light-ish sand (mostly just to key) and then go ahead and prime. Others say the woodwork should be sanded as much as possible and where ever possible returned to bare wood before doing any painting. They say that the paint will be far more effective that way (esp. Marstons).

I've also had mixed opinions on priming. Some people are saying that there is no need to prime the wood. Martson and Langinger said this. Yet I thought priming was an absolute must. Again, any thoughts?

Cheers

Max

 

[wobblycogs]

Personally I try to get back to bare wood but if it's going to be difficult to achieve and not on show I'll just ensure that there's not a scrap of loose paint.

Your real problems come when some muppet in the past hasn't keyed the previous paint properly before applying their new coat. In that situation you tend to find that as you sand the edge of a chip the previous layers will start to flake away just at the point when you think your getting them thin enough that you think it would be ok to paint over. Grrrr. Worse the poorly applied layer always acts as a weak point and will bubble up / split / flake within a year or two.

As for priming I don't don't but I do undercoat thoroughly as I find it makes it easier to apply the gloss top coat(s)

 

[Jacob]

......you tend to find that as you sand the edge of a chip the previous layers will start to flake away just at the point when you think your getting them thin enough that you think it would be ok to paint over. ....

In a nutshell that's what's wrong with a lot of modern paint - the surface may be OK but it's getting semi-detached from behind AND letting in and holding water.
Whereas linseed paints seem to deteriorate the opposite way - from the surface down. It goes chalky and will wash off over the years but the underneath stays stuck on. Even when the paint is all gone there is a residue of oil remaining and repainting is dead easy - just splash on some more oil, followed by paint a week or so later.

 

[kostello]

i've used superdec with good results....................

i don't think you need to use a separate primer with super dec......

you won't get a high gloss finish with water based paints.......

the marston and langinger paint is probably just the same stuff as superdec....

 

[drillbit]

http://www.google.co.uk/products/catalo ... CDIQ8wIwAw

That might be useful if you haven't already got one...