problem with blown paintable wall

[donmaico]

I hung such a wallpaper in my bathroom with a view to painting over it with kitchen and bathroom emulsion. Despite several tricky corners, I felt I did a good job with the paper and all went well until i came to paint it. For some reason, it has failed to dry completely (after a year it still feel tacky) but what is even worse is that it has what look like scratches in various areas made by a very persistent cat capable of jumping 5 or 6 feet. I can't for the life of me think what the cause of the problem is but I suspect the paint itself (BQ Colours Premium soft sheen) is faulty as I have used the same paper in another room and covered it with Dulux Soft Sheen with no problem at all. Nor do I know how to remedy it.
A decorator, I spoke to suggest covering it with a Zinner primer such as 123 and then using another brand of emulsion over it but I cannot see how that would solve the problem if the emulsion I used hasn't properly adhered to the surface of the paper. He reckoned the two weren't compatible because they were both vinyl products, which didn't make much sense to me as I would have thought that would have been made clear on the products themselves. Can anyone enlighten me? Thanks

 

[JohnD]

how do you ventilate this bathroom?

 

[JohnD]

kitchen and bathroom

are you sure that it is a Vinyl paint?

 

[donmaico]

how do you ventilate this bathroom?

i open the window usually once a day to let steam out

 

[donmaico]

are you sure that it is a Vinyl paint?

in as much as i assume any soft sheen bathroom and kitchen paint is .It doesn't say so on the container but it does state that it is moisture and steam resistant so I assumed vinyl was added to it

 

[opps]

What paper did you use?

It sounds like the steam is causing the paint to craze. I would expect that to happen higher up the walls because steam rises.

"Bathroom" paints might be steam resistant but they aren't steam proof. Excess steam makes them become soft.

Unless you fit an extractor fan, you might need to paint the walls with oil based eggshell or tinted Zinsser BIN (shellac suspended in alcohol).

 

[donmaico]

What paper did you use?

It sounds like the steam is causing the paint to craze. I would expect that to happen higher up the walls because steam rises.

"Bathroom" paints might be steam resistant but they aren't steam proof. Excess steam makes them become soft.

Unless you fit an extractor fan, you might need to paint the walls with oil based eggshell or tinted Zinsser BIN (shellac suspended in alcohol).

Its this one here https://www.diy.com/departments/wal...ped-textured-paintable-wallpaper/36699_BQ.prd. The "scratches" are just paint peeling off in particular areas of the wall. There is about 6 or 7 of them.
That Zinsser you are referring to I am told takes about a month to properly cure.

 

[opps]

Zinsser BIN is touch dry in 15 minutes, recoatable after 45 and cures in 1 to 3 days.

http://www.zinsseruk.com/product/b-i-n/

Waterbased paints take a couple of weeks to fully cure and will fail to cure properly if they are subject to temperature extremes or high levels of humidity.

https://www.dulux.com.au/applicator...on/drying-and-hardening-of-water-based-paints

Oil based paints can take 6 weeks or more to cure but cure via oxidisation and thus are not as susceptible to humidity. Gloss however, will become more matt if subjected to humidity before becoming touch dry.

 

[donmaico]

Zinsser BIN is touch dry in 15 minutes, recoatable after 45 and cures in 1 to 3 days.

http://www.zinsseruk.com/product/b-i-n/

Waterbased paints take a couple of weeks to fully cure and will fail to cure properly if they are subject to temperature extremes or high levels of humidity.

https://www.dulux.com.au/applicator...on/drying-and-hardening-of-water-based-paints

Oil based paints can take 6 weeks or more to cure but cure via oxidisation and thus are not as susceptible to humidity. Gloss however, will become more matt if subjected to humidity before becoming touch dry.

in which case it would probably be better to let it harden fully over a period of 3 days .My only concern is whether painting anything over what appears to be a somewhat unstable surface will do any good. I have not seen anymore "scratches" appear but that doesn't mean they won't in the future

 

[opps]

in which case it would probably be better to let it harden fully over a period of 3 days .My only concern is whether painting anything over what appears to be a somewhat unstable surface will do any good. I have not seen anymore "scratches" appear but that doesn't mean they won't in the future

The 1 to 3 days quoted refers to the rate at which the alcohol will evaporate. Airflow and heat will accelerate the curing process.

I would recommend protecting it from steam for a day but showering the next day should be fine.

BIN is a great product. It will adhere to most surfaces and provided that none of the existing paint is loose I don't envisage any problems, nor would I expect the original paint to craze any further.

BTW, use a mohair type roller, not a foam one. The alcohol will cause the foam to breakdown and the roller will expand until becoming unusable. Clean brushes and rollers with household ammonia. It is alkali and brakes the paint down, rather than meths which just dilutes the BIN and leaves some residue behind. Zinsser make a brush cleaner but the ammonia is much cheaper and faster.

 

[donmaico]

The 1 to 3 days quoted refers to the rate at which the alcohol will evaporate. Airflow and heat will accelerate the curing process.

I would recommend protecting it from steam for a day but showering the next day should be fine.

BIN is a great product. It will adhere to most surfaces and provided that none of the existing paint is loose I don't envisage any problems, nor would I expect the original paint to craze any further.

BTW, use a mohair type roller, not a foam one. The alcohol will cause the foam to breakdown and the roller will expand until becoming unusable. Clean brushes and rollers with household ammonia. It is alkali and brakes the paint down, rather than meths which just dilutes the BIN and leaves some residue behind. Zinsser make a brush cleaner but the ammonia is much cheaper and faster.

Ok thanks for that advice

 

[donmaico]

had a chat with a decorator today and he reckoned the problem was caused by me not wiping off excess wallpaper paste. The paint simply won't stick to it, so he suggested removing the nibs off with a kitchen scouring pad and then applying some oil based undercoat over the affected areas and then covering it all with the emulsion I used

 

[opps]

Without having photos it is difficult to agree or disagree.

He is correct that excess wallpaper paste can be a problem but I would have expected you to have noticed when you applied the emulsion. It is possible that steam is reactivating the paint/glue mix. The oil based undercoat will seal the areas and prevent the steam from activating the glue but the waterbased emulsion still won't be happy with high levels of moisture.

Personally I would still go down the BIN route.

 

[donmaico]

Without having photos it is difficult to agree or disagree.

He is correct that excess wallpaper paste can be a problem but I would have expected you to have noticed when you applied the emulsion. It is possible that steam is reactivating the paint/glue mix. The oil based undercoat will seal the areas and prevent the steam from activating the glue but the waterbased emulsion still won't be happy with high levels of moisture.

Personally I would still go down the BIN route.

i probably noticed but never thought it would be a problem, after all, I have hung liner paper in other rooms and had no problems with the paste. I will go down the BIN route as you suggest covering the whole wall, just will make sure the windows are wide open if there are any nasty fumes involved. I'll assume the emulsion will be happier then

 

[opps]

i probably noticed but never thought it would be a problem, after all, I have hung liner paper in other rooms and had no problems with the paste. I will go down the BIN route as you suggest covering the whole wall, just will make sure the windows are wide open if there are any nasty fumes involved. I'll assume the emulsion will be happier then

BIN stinks but the smell is only alcohol. You could wear a charcoal filtered mask if you want. With the mask on, you won't be able to smell anything.

https://www.amazon.co.uk/Beeswift-BB3030-ABEK-READY-MASK/dp/B00PH53COO

The smell will (almost) completely disappear after about 45 mins (or less).

Just to clarify, I am suggesting that you apply two coats of BIN and then nothing else, ie no emulsion. The main caveat being that BIN can only be tinted to pastel/mid colours and that the colour match will not be exact. Take a sample of your current paint and ask your local decorators' merchant if they can get close to the colour.