paint peeling from windows

[sawdust1]

A friend of mine is having trouble with paint peeling from his 20 windows, luckily i was to busy to make his windows, so he asked a local
joinery to make them, he thinks the timber used was Sapele, they have been painted 4 times and after a year the paint has peeled off in
big patches, the joinery has washed their hands of the problem, he has been in contact with a couple of paint suppliers with no help.
Just wondering if anyone on here has had a similar problem, it sounds to me like they where made from iroko as it can be quite oily.
He has tried water and oil based products, but nothing stays on for long.
Was wondering if he rubs back or strips back to wood and uses a coloured stain like Cuprinol's Garden Shades or similar this would
stay on.

 

[RobinBHM]

I bet the problem is the windows were manufactured and installed during the winter.

Pretty much all joinery manufacturers used water borne paints. They completely stop curing below 12 degrees. What typically happens is the joinery company leaves insufficient time between coats - or sprays in the afternoon and leave the joinery overnight in an I heated factory. The paint coalesces but it doesn't cross link.

Once fitted in the winter, the paint doesn't cure, sometimes for months. During that period, water penetration gets underneath and adhesion to the timber is lost.

My guess is your friend is overpainting but adhesion of the base layer has failed.


Do you know what the paint make was used?


The other key is joinery detailing, for example:

3mm radiuses to external edges
Radius to cill groove
V groove at frame and sash joints
Avoidance of water trapment - especially on dummy sashes
Sufficient water shed angles and drip mouldings


I made joinery mostly from iroko for nearly 20 years, using paint from Teknis, Remmers, Sigma.

Despite it being an oily timber, I had no problems with adhesion -other than winter during problem above.

Mostly we used a degreaser to remove extractives from surface cells within 2 hours of primer coat - but even without this there were minimal issues.

 

[mr edd]

I would remove the loose material with a hand scraper, sand back to bare and prime with aluminium primer, followed by two coats of oil based undercoat and an oil gloss topcoat.

Alu primer sticks like....something that sticks pretty well.

The prep involved will be a pain, it depends what lengths your mate wants to go to.

I have not used the garden shades? So don't know but looks a bit DIY shed, would not use it on joinery

Cheers Edd

 

[sawdust1]

Thanks for the replies.
They where made and fitted in the summer, i know that cause the house was completely renovated and i did a lot of work to it.
I will find out the various paints they used, when i asked about it he did say at one time they used an Alu primer.

 

[Jacob]

Problem I've had all my life so I always supplied external stuff either bare wood or ali primer - then all responsibility goes to the painter and not to me!
But thats not good enough for me when my own stuff starts peeling, which solved about 10 years ago by starting to use linseed oil paints - which simply do not peel at all, seem to stick to anything.
Instead they weather from the surface rather than peeling off in sheets, and can be revived easily with no need to burn off etc, just paint on more oil or paint.
I'd often wondered why old stuff (100+ years) I was renovating never showed any sign of having been stripped with a blow lamp. Answer- they used linseed oil paints which never need it. Just add more oil and/or paint.
Google Allback paint. https://www.google.com/search?q=all...2j0i22i30l7.3613j0j4&sourceid=chrome&ie=UTF-8
PS Ali primer fails too. With linseed no primer needed.
I came to the conclusion that all modern paints are craap externally. People keep going on about one modern wonder paint or another but until the stuff has been up and survived for 20 years you just don't know.
Some of my own joinery is in need of repainting now, after being up for up to 10 years, but no peeling or deterioration of the wood, just looks a bit thin and tatty here and there. I've had modern paints fail in 3 with rot set in behind it.

 

[Doug71]

Is the paint peeling off back to the bare wood?

I always use ali primer, it is good stuff.

Maybe they originally used ali primer (spirit based) and then an acrylic undercoat/topcoat which hasn't stuck to it properly? Once the paint starts failing it doesn't matter what you put on top it will still keep coming off, the only thing you can do is strip it off and start again

I like Dulux Ultimate Opaque as a finish, it goes straight on over the ali primer and gives a satin finish, it's an opaque stain if that makes sense

 

[Rorschach]

Get some PVC fitted?