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Oil or Water based paint for external wood?

C

Cesare

pfm Member
It's that time again to get the house scaffolded and break out the paint stripper. Last time around we went with an oil based paint, and it's held up well in most places (something like 14 years since we painted it last).

So the question is, should we go again for oil based, or move to a water based system this time around? I'll be stripping to bear wood, so assume it's all been previously painted with oil based, and will use the recommended primer/undercoat. There's lots of black soffit board, and white window frames.

My instinct is that the oil based systems aren't what they used to be, and water has come on, but we're a mile from the sea, so the weather isn't kind to exteriors. Obviously i'll ask the local merchant for their advice, but it's always good to get other thoughts on it...
 
Oil - 110 times out of 100.

Primer, under and top coat. Of all three, IME, water-based primer in particular is the real pits for demanding uses.

Use ranch/breathable top coat - very easily worth the extra cost. Stays white too, if white is what you want, or at least in the ones that I've used. I have some that must be at least 10 years from application now, on barge boards that get absolutely hammered by the sun. Hose them off, shift the algae, and they are still fine.
 
Just doing this now. Oil, no contest. Using Little Greene ‘Tom’s oil exterior eggshell’. Not the cheapest, but very good.
If you are going back to bare wood, I can highly recommend giving it a good soaking of Dulux Weathersield exterior preservative before the Little Greene primer / undercoat. We did this 10 years ago and they’ve held up really well considering the battering they take up here in the wilds of Wales.
 
I didn't like the colours available when I needed to paint my fence.

I used masonary paint watered down a bit. 2 coats. No primer. First coat watered down quite a bit.
8 years later, still looks great, although I want to paint it red, green and yellow
 
That is a real turn-up. Masonry paint is a very different thing to other paints. I am surprised that it has stuck that long.
Maybe not a repeatable experiment?? :)
 
I'd probably recommend Sadolin Extra Durable ebony for the black soffits. It is very durable, keeps it's looks and weathers as opposed to peeling over time. Oil based

More recently Sadolin Superdec has appeared, water based.
Haven't used it (yet) but read very positive things.
 
Ponty said:
Just doing this now. Oil, no contest. Using Little Greene ‘Tom’s oil exterior eggshell’. Not the cheapest, but very good.
If you are going back to bare wood, I can highly recommend giving it a good soaking of Dulux Weathersield exterior preservative before the Little Greene primer / undercoat. We did this 10 years ago and they’ve held up really well considering the battering they take up here in the wilds of Wales.
Click to expand...

I also use Little Greene paints. Highly recommended.
 
Cesare said:
It's that time again to get the house scaffolded and break out the paint stripper. Last time around we went with an oil based paint, and it's held up well in most places (something like 14 years since we painted it last).

So the question is, should we go again for oil based, or move to a water based system this time around? I'll be stripping to bear wood, so assume it's all been previously painted with oil based, and will use the recommended primer/undercoat. There's lots of black soffit board, and white window frames.

My instinct is that the oil based systems aren't what they used to be, and water has come on, but we're a mile from the sea, so the weather isn't kind to exteriors. Obviously i'll ask the local merchant for their advice, but it's always good to get other thoughts on it...
Click to expand...
Both things you say are true. Oil based generally less good since 2010, water based getting better all the time although it still lacks the body of oil.

Good oils are sikkens and sandtex flexigloss. Best water based tends to be from abroad, including Benjamin Moore from the USA. Sadolin is ok but you need to leave longer between coats despite being water based and the finish isn't that great if you seek shine.

A big advantage of water based is flexibility and fast drying times, if you are lucky you can finish a job in a day, whereas something like sikkens you apply in the morning and that's it for the day! Sometimes still soft the following day.
 
Sandtex sounds familiar for the black gloss weatherboard/soffit, I think the windows were a dulux weathershield though (from the old dented tin in the garage). Ok, I think i'm sold on oil based again...

As for prep, this does give me more options to just sand/fill the decent bits as oil on oil is less likely to fall off.

I've got acres of pebbledash to paint too, but a 19 year old who is home this summer so he's going to earn his keep.

Scaffolding going up next week...
 
Ponty said:
Just doing this now. Oil, no contest. Using Little Greene ‘Tom’s oil exterior eggshell’. Not the cheapest, but very good.
If you are going back to bare wood, I can highly recommend giving it a good soaking of Dulux Weathersield exterior preservative before the Little Greene primer / undercoat. We did this 10 years ago and they’ve held up really well considering the battering they take up here in the wilds of Wales.
Click to expand...
I used Little Greene water based eggshell for the top half of the garage door; dreadful. Used Tom’s oil based eggshell for the bottom half; different class.
 
Cesare said:
Sandtex sounds familiar for the black gloss weatherboard/soffit, I think the windows were a dulux weathershield though (from the old dented tin in the garage). Ok, I think i'm sold on oil based again...

As for prep, this does give me more options to just sand/fill the decent bits as oil on oil is less likely to fall off.

I've got acres of pebbledash to paint too, but a 19 year old who is home this summer so he's going to earn his keep.

Scaffolding going up next week...
Click to expand...
Old ( pre 2010) weathershield is held in high esteem.

I recommended sikkens oil based gloss earlier,which I've used a lot. Interestingly (or not) the white has always stood up better than black. It's probably because it absorbs more heat/light which tests the paint more, it might additionally be to do with pigment. I don't know for sure but bear it in mind especially if facing direct sun.

I think many people tried early or low quality water based paints and dismissed them for ever more. That's harsh, they are much improved and really easy to use.

That said, it's true they've not been proven over long periods and in any case good quality oil is a safe option if you prep well.
 
roman said:
It's probably because it absorbs more heat/light which tests the paint more
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Get a really hot and sunny day - find some black and some white in full sun - touch them...

To get opacity, pretty much all paint is loaded with titanium dioxide, which is sort of not-quite white. Colours are the added by milling in pigments - based on cost and logic, black would be carbon black. Surprisingly large numbers of yellows/reds/browns/greens can be got from different forms of iron oxide, the rest - pass.

The hassles with water-based paints is that you are fantastically restricted in the chemistry of the polymers (binders/film-formers) that you can use. There isn't vey much at all that you can attach to a polymer to make it water-soluble/dispersible - basically acid or amine groups. Coming at it from the other direction, manufacturing polymer dispersions, you need lots of surfactants.

Durability is massively influenced by fillers and the chemistry of the polymers (binders/film-formers).
 
Vinny said:
Get a really hot and sunny day - find some black and some white in full sun - touch them...

To get opacity, pretty much all paint is loaded with titanium dioxide, which is sort of not-quite white. Colours are the added by milling in pigments - based on cost and logic, black would be carbon black. Surprisingly large numbers of yellows/reds/browns/greens can be got from different forms of iron oxide, the rest - pass.
Click to expand...
Sure, just like black/white cars. But I'm not aware of them suffering in the same way. I guess it's the difference between industrial finishes and what we are given access to in a pot!
 
roman said:
Sure, just like black/white cars. But I'm not aware of them suffering in the same way. I guess it's the difference between industrial finishes and what we are given access to in a pot!
Click to expand...

Massively different in so many ways. How far it has got, I don't know, but an awful lot of industrial coatings are now applied electrolytically. Getting a paint assembly that can cope with the vast movement in a metal car body as it heat and cools, let alone things like road salt, is a huge technological achievement, and how often do modern cars rust? An incredible achievement really, even though at first sight it seems totally trivial.
 
Vinny said:
That is a real turn-up. Masonry paint is a very different thing to other paints. I am surprised that it has stuck that long.
Maybe not a repeatable experiment?? :)
Click to expand...

fence is 9 metres + long, painted both sides.
 
Ponty said:
Just doing this now. Oil, no contest. Using Little Greene ‘Tom’s oil exterior eggshell’. Not the cheapest, but very good.
If you are going back to bare wood, I can highly recommend giving it a good soaking of Dulux Weathersield exterior preservative before the Little Greene primer / undercoat. We did this 10 years ago and they’ve held up really well considering the battering they take up here in the wilds of Wales.
Click to expand...

Yes , got one window not doing too bad which was done with water paint but now i almost always stick to Solvent paint for outside and often inside if i can cope with the stink
 
hifinutt said:
Yes , got one window not doing too bad which was done with water paint but now i almost always stick to Solvent paint for outside and often inside if i can cope with the stink
Click to expand...
Again, depends on conditions. If painting dark interior areas in white gloss I recommend using water based. It is far better ( but not perfect) at resisting yellowing. Add to that less stink and much faster drying and it's no contest.
 
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