My paint is bubbling up, please help

[banjodeano]

Hiya Guys.
We moved into a new house a few months ago, and whenever we come to repaint the emulsioned walls with new emulsion, it bubbles up in patches. not all over, just here and there.
What can i do about it, its a 60's house that looks like it has been replastered at some time, probably a couple of years ago, not sure if that makes a difference.
What can i do guys?
thanks Dean

 

[Fred61]

There are many things that will cause this. The thing to understand is that emulsion is water based and so are many other things that are put on your walls. The blisters can be as a result of wallpaper paste in an old layer becoming wet again. It can also be a layer on distemper becoming wet and unstable. As I said there are many possibilities. Theses are just two. So the solution is down to chemistry if you use an oil based paint then this won’t cause a reaction with the water based paint etc that is on your wall or ceiling. Now this is easier than it first would appear. All you need to do is to use a cheep oil based undercoat to paint with. This creates the barrier and will stop the blisters. You just then paint with your normal colour paint and hay presto fixed. Easy as that
So a few more pointers. Make sure it’s a good coating as any places where your paint is to thin it may still blister. So possible need for two coats.
So what is oil based ??? The manufacturer has now made it very hard to identify oil base as it’s not considered eco!! Just look at how to clean your brush. If it says clean with water it’s water based paint if it says use a proprietary cleaner ( that’s white spirits ) that’s the one you want. Now there are many oil based sealant paints out there and yes they all do the same job. But they are a waist of money cheep undercover will do the same job. I hope this helps you. Fred

 

[banjodeano]

There are many things that will cause this. The thing to understand is that emulsion is water based and so are many other things that are put on your walls. The blisters can be as a result of wallpaper paste in an old layer becoming wet again. It can also be a layer on distemper becoming wet and unstable. As I said there are many possibilities. Theses are just two. So the solution is down to chemistry if you use an oil based paint then this won’t cause a reaction with the water based paint etc that is on your wall or ceiling. Now this is easier than it first would appear. All you need to do is to use a cheep oil based undercoat to paint with. This creates the barrier and will stop the blisters. You just then paint with your normal colour paint and hay presto fixed. Easy as that
So a few more pointers. Make sure it’s a good coating as any places where your paint is to thin it may still blister. So possible need for two coats.
So what is oil based ??? The manufacturer has now made it very hard to identify oil base as it’s not considered eco!! Just look at how to clean your brush. If it says clean with water it’s water based paint if it says use a proprietary cleaner ( that’s white spirits ) that’s the one you want. Now there are many oil based sealant paints out there and yes they all do the same job. But they are a waist of money cheep undercover will do the same job. I hope this helps you. Fred

Thanks for taking the time to replyFred.....so let me get this straight, if i use an oil based paint as an undercoat, does that mean i can use any umulsion over the top of it, whether its oil based or water based emulsion?
Thanks Dean

 

[Fred61]

Yes with no problem as the oil paint provides the chemical barrier to the water. The new emulsion water cannot effect the old coverings on the wall. So you can use any run of the mill paint you like and as the undercoat is intended to be over painted the emulsion will stick just fine as well. Fred

 

[banjodeano]

Yes with no problem as the oil paint provides the chemical barrier to the water. The new emulsion water cannot effect the old coverings on the wall. So you can use any run of the mill paint you like and as the undercoat is intended to be over painted the emulsion will stick just fine as well. Fred

awwww, thanks mate

 

[ic1927]

Just make sure you allow the oil undercoat to fully dry otherwise you'll get a cissing effect with the emulsion.

 

[banjodeano]

Just make sure you allow the oil undercoat to fully dry otherwise you'll get a cissing effect with the emulsion.

will do, thanks

 

[opps]

Just make sure you allow the oil undercoat to fully dry otherwise you'll get a cissing effect with the emulsion.

Agreed. You can add an oxidising agent such as Terebene in the U/C to speed up the curing time.

 

[banjodeano]

Yes with no problem as the oil paint provides the chemical barrier to the water. The new emulsion water cannot effect the old coverings on the wall. So you can use any run of the mill paint you like and as the undercoat is intended to be over painted the emulsion will stick just fine as well. Fred

Would pva glue work?

 

[pilsbury]

Would pva glue work?

That’s water based I think.

 

[opps]

Would pva glue work?

PVA should never be used under water based paint. The water in the paint will soften the PVA.

 

[banjodeano]

PVA should never be used under water based paint. The water in the paint will soften the PVA.

Thanks...i didnt know that

 

[Doggit]

I had an Irish painter that did an outside job for me, and he always put a large glug of PVA into the can of masonary paint, and then mixed it in well; now this is considered a complete no no, but it damned well stuck to the walls. PVA will soften if left wet, but that's not to say that it would if you left it to dry, and then painted on it; not enough water in the emulsion, not enough time, to soften it. The real drawback here, is that the PVA would leave the surface slightly uneven.

But you haven't mentioned which emulsion paint you used.

 

[banjodeano]

I had an Irish painter that did an outside job for me, and he always put a large glug of PVA into the can of masonary paint, and then mixed it in well; now this is considered a complete no no, but it damned well stuck to the walls. PVA will soften if left wet, but that's not to say that it would if you left it to dry, and then painted on it; not enough water in the emulsion, not enough time, to soften it. The real drawback here, is that the PVA would leave the surface slightly uneven.

But you haven't mentioned which emulsion paint you used.

Thanks for taking the time to reply Doggit....
I have used Wickes cheap white matt emulsion, and Crown white matt emulsion, and another well known brand that escapes me, all were matt and applied with a roller, and in various parts of the house, i am beginning to wonder if the walls have been painted with silk vinyl or something,i just thought it was all done in normal emulsion paint, and although i have been told you cant put emulsion on vinyl or something, i thought it wouldnt make a deal of difference, but jesus, its like putting paint stripper on it, bubbles up like nitromorse has been applied, and i am thinking it may have been silk vinyl because you can scrub it with a wet cloth and the colour will not come off, but the paints i have used come straight off..

 

[Doggit]

Vinyl silk wouldn't react like that, so I'm not sure what the problem is. Unless you're going to use a solvent based undercoat as a block, then you've got to work out how much needs sanding down when it bubbles, and then apply another coat (or two) afterwards. On the bits that haven't bubbled, can you then apply another coat safely.

It sounds as though the the wall that they painted onto, with whatever they used, wasn't prepared properly first.