Peeling paint is driving me mad!

[Steve Blackdog]

This is probably about wood rather than decorating, but if anyone knows about exterior decorating, I could do with some advice.

Some years ago we had a very old exposed exterior door stripped (by cold dipping). It was cleaned up, thoroughly washed off and danish oiled (not by me!). It is one of those old studded doors, with oak studs, and so a real pain to decorate.

After about a year we noticed that the danish oil had gone sticky and in a number of places it was completely washed off by the weather. We couldn't just top up the danish oil as it had a stain in it and so started to look a bit like a tiger pattern.

So I wire-wooled the whole door clean, went over it with white spirit, made sure it was dried out then sealed it with Sikkens instead, which is spirit based. I was pleased as punch - it looked great.

After about six months the Sikkens started to bubble, exactly where the danish oil had gone before. I rubbed it down and touched it up again. A few months later - same again. To put this into context, you could wipe it with a soapy cloth and large patches would wipe off on the cloth.

Fast forward to last year, I stripped the door again, with Nitromors and washed it off. I decided to rehang the door and leave it unfinished for a couple of months to let it properly dry out. In the areas that the finish would not adhere properly, the underlying timber has become very slippery and slightly spongey. When it was fully dried out, it seemed to be fine.

During a dry spot last summer, I prepped, painted the problem areas with wood hardener, and primed the wood and then glossed it. It looked great.

Now the undercoat and top coat have lifted at the problem areas - the paint has a skin on it you can push off with your finger, exposing bare wood. Where this has happened, there are spots of black mould.

I have concluded that the original danish oil was probably applied before the door had fully dried out. I suspect that the wood (pine) has started to rot, such that it cannot be fully dried. Or at least it is 'infected' with some kind of fungus.

I can't cut out the offending wood. I want to be able to do something to it to make paint stick to it.

All advice gratefully received.

Cheers

Steve

 

[Blister]

Steve

I think there is a product called

UPVC , they say its maintenance free

Or should that be " Unmaintainable "

Hope you find a solution :wink:

 

[tomatwark]

Steve

Was the Sikkens and the paint you used last year microporous, if so this may be your problem and not the wood.

If it was microporous you want to strip it back again and try a good quality oil based exterior paint, bought from a trade supplier and not one of the DIY sheds.

MIcroporous paint is ok on new work but can be a bloody nightmare on old stuff.

Sikkens is funny stuff as well, I have had customers put it on windows that have been burnt off and it has been fine and one the next window along it came off.

Tom

 

[Jacob]

I've always had poor experience with paint on old joinery,whatever the supposed quality of the paint. Until I started using Holkham linseed oil paints. There's a thread here. Note the dates - it amounts to a 3+ year trial and some of the work was done in late autumn. Frost and cold doesn't matter as long as the surface is dry when you put it on.
It's pricy per litre but it goes a very long way. It sticks to everything I've tried it on, and holds down old paint even if it's a bit flaky or dirty to start with.
Brilliant stuff. I won't be using anything else in future.

 

[studders]

If it's rotting wood that's causing the problem you might get away with something like this?

 

[Jacob]

Just noticed you had it stripped. Stripping is the death of old joinery as a rule. You might need to neutralise it or otherwise get rid of any remaining caustic soda. Caustic soda plus oil (or oil paint) makes soap. It'll just wash off, or detach like yours has done. Perhaps wash it first with sugar soap solution and then soak in vinegar? I'm only guessing - I've never done this myself, having seen too many things wrecked by dipping.

 

[deserter]

I would call a paint manufacturer ICI is known to have the best customer service dept. and ask them their advice, frequently ICI will send a rep to inspect problem areas if they can't help over the phone.
In my opinion however I think the problem will be being compounded by adding the oil based products and oil, and sorry to contradict what has already been said but a microporous finish will be better as it will allow the contaminant to escape the surface where as a traditional oil finish Is going to seal the problem which will in turn push the finish off the surface.
I am not trying to speak out of turn and as I say I would alway contact ICI to get their advice (the number is on the back of every tin), however in my past I used to sell paint etc. for a DDC trade outlet and so have been trained by ICI, Leyland and Akso Nobel.

 

[Steve Blackdog]

All this advice is very helpful, not least Blister's uPVC suggestion. However, SWMBO is more interested in aesthetics and this old studded door is a 'feature'!!

The suggestion of speaking to ICI is something I'll try anyway - a good tip.

I used the stuff Studders was suggesting - I thought that would do the trick.

Sadly, I suspect Jacob may have hit the nail on the head. The door should never have been dipped. It has a very strange construction with vertical boards T&G on the outside and horizontal T&G boards on the inside, so the wooden pegs cannot be seen from the inside at all. This creates a sandwich/lamination in which residues of the caustic soda could easily have been trapped. If that has happened, I guess I might be looking at disassembling the door and cleaning the boards from the inside. (UGH)

The door is around 200 years old, so I bet any wood glue between the boards will have been killed by the dipping, if there was any glue in the first place. It might be easier to get used to paining it every year - I could try the linseed oil paint and see what difference that makes, I suppose.

 

[ProShop]

Jacob makes a good point ref the evils of dipping, although it's great for actually removing old paint & varnish etc it also strips the wood of it's natural fluids causing all sorts of problems as you've found out.

Have you tried an aluminium primer, this is very good against resin & oily surfaces.

 

[Steve Blackdog]

Jacob makes a good point ref the evils of dipping, although it's great for actually removing old paint & varnish etc it also strips the wood of it's natural fluids causing all sorts of problems as you've found out.

Have you tried an aluminium primer, this is very good against resin & oily surfaces.

Not only have I not tried it, I've never come across aluminium primer! I will add it to my shopping list

 

[deserter]

Be certain you want to try alluminium primer before you do once it's on it stays on forever.
It is very good but just warning it is permanent.

 

[ProShop]

Jacob makes a good point ref the evils of dipping, although it's great for actually removing old paint & varnish etc it also strips the wood of it's natural fluids causing all sorts of problems as you've found out.

Have you tried an aluminium primer, this is very good against resin & oily surfaces.

Not only have I not tried it, I've never come across aluminium primer! I will add it to my shopping list

It's also very good for dispersing & reflecting heat, useful on south facing doors & windows & sun trap areas.

 

[Hudson Carpentry]

Steve

I think there is a product called

UPVC , they say its maintenance free

Or should that be " Unmaintainable "

Hope you find a solution :wink:

:evil: Wash your mouth out sir, this is a woodworking forum and wood looks far better than plastic.

Steve im sure the other options will work but if you fancy practicing some wood work you can cut the wood out :wink: You are painting the door so you can always do whats called a dutchman. You can use a router and jig to cut away as 5mm of material in a square or rectangle pattern and replace with new material. Sand flush and if the door has details you can route these back in. As you are painting if you are not that accurate with the dutchman you can fill the edges, sand and the paint will cover all.

 

[Phil Pascoe]

Get one of the commercial rotten wood hardeners- they are glorified superglue - coat the area with that- then use alumium primer??