Exterior Paint problem

[billm]

Hi guys, I am gearing up to paint the outside of the house Black/White as per the attached photos. However you can see that the white is peeling badly. It transpires that my neighbour painted the white for the previous occupant several years ago and he said he had a really tough job trying to make it stick. So it looks like there is a problem there.

I intend to scrape off all the loose paint and sand it down with rough paper. But I am looking for advice on how to prepare it for the paint.

Will a solution of water/PVA do the job or are there other better ways/products of preparing it for white undercoat.

Many thanks


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[xr4x4]

what is the surface made out of? and what finish where you hoping for.

 

[misterhelpful]

Wow, that really has seen better days!

For best results you really should strip/scrape everything off and start again.
Don't use PVA as it will cause similar problems in the future - it's not suitable for use with paint.
If you can't or don't want to strip everything, then you can remove all the loose stuff and use something like Zinsser Peel Stop to seal and bind the surface:
http://zinsseruk.com/shop/Product.aspx?cId=130&pgId=360
This way is not going to give you a perfectly smooth finish but will stop the flaking before you prime/undercoat (if timber/ply) and topcoat.
It will work on both timber and render but I can't quite make out which the white panelling is, as xr4x4 has alluded to.

 

[roughcaster]

I am not a painter,, but i can hear them all shouting out to you,,,,"DON'T EVEN THINK ABOUT USING PVA".

 

[misterhelpful]

I am not a painter,, but i can hear them all shouting out to you,,,,"DON'T EVEN THINK ABOUT USING PVA".

...and you'd be right!

 

[billm]

I haven't been close up to inspect it yet but I assume its some form of boarding thats been painted.

As for finish, anything either smooth or rough I'm not bothered as long as it sticks up there, is white and doesn't peel. As you can see its high up so it doesn't have to stand up to close inspection

Is there a textured product that would make an easier job without costing a fortune ?

 

[misterhelpful]

I can't think of a specific paint or coating that can be applied to exterior wood.
If you are using a water based undercoat you could add fine sand to it, but I doubt that would really hide the imperfections very well. Assuming it is wood then using an oil-based topcoat will be best.
If it were render, I would suggest using a heavily textured masonry paint but it wouldn't be suitable on wood.
Looking at the pictures, you might find that once you get up there and start scraping it will all come off very easily. Fingers crossed!!

Actually, just looked at this and it can be used on plywood but have never tried it myself, you'll still need the binder though.
http://www.johnstonestrade.com/product-range/product.aspx?product=Jontex_High_Build_Textured_Masonry

 

[georgiepie]

for the white part id use a good water based masonry paint any oil based paint will weather and crack again believe it or not i painted my wooden fence and back gate in jonstones black masonry paint 2 years ago and it looks like it beens done yesterday absolute fantastic finish and on rough sawn wood too!

 

[billm]

Hi I have had a rummage in the shed and found 2 tins of Weathershield White masonry paint, water based, that I didn't know where there !

So after a damn good scraping, and sanding down, I'll use that and fingers crossed it'll stick and look good.

Thanks for the advice guys.

 

[TheDec]

I think you'll find these boards have a type of plastic coating on them that is a finish in itself. If i'm correct no waterbased masonry paint will adhere, if you are intent on painting them then they are going to need all the help with regard to adhesion that they can get.

I am not going to offer you any promises here but in your situation I would choose a different paint system , firstly I would apply either Dulux Trade Ultra Grip Primer, or Dulux Trade Super Grip Primer and then consider an oil based paint system as your finishing coats.

Like I said no promises, but a waterbased paint system simply won't work.

Dec

 

[Growler]

The surface is sucking the life out of any paint so..
Scrape it.
Sandpaper it.
Dust it off.

Apply this first..

http://www.johnstonestrade.com/product-range/product.aspx?product=Stabilising_Solution

then, go with a masonry finish, preferably a pliolite but smooth Johnstone's masonry should do it.

Don't paint it "dry" without the stabiliser as it wont do.

 

[TheDec]

I think we need to establish here exactly what we are dealing with, the boarding has a smooth finish and the problems that the op has is a lack of adhesion, he will be applying his paint on a smooth surface not unlike Formica.

Therefore with the surface being already smooth the last thing he should do is apply a stabiliser, that would make it even worse.

Also these boards are an integral part of the property and not just decorative, consequently if he was to tackle these works by harsh sanding, and scraping, he is liable to puncture the protective coating and allow the ingress of moisture.

This action should be avoided at all costs.

Dec

 

[misterhelpful]

Please put us out of our misery, billm - what is the surface?

 

[Growler]

You'll have no problems if you do as I recommend.

I know..........because I've done it.

 

[jondecs]

how old is the property? 1930's ? Would be render surely.

Looks like classic case of Stabiliser applied to a sound rendered surface. this makes it too glossy and masonry paint wont stick to glossy surface.