Is there a painter and decorator in the house?

gramps

gramps

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Okay so painting and decorating isn't one of my interests/skills and I haven't done any for longer than I care to remember ... at least 25 years - but having just retired I have to do my bit to keep SWMBO happy without getting in the decorator again.
One of the extensions to the house that I have used for work storage has been cleared and is the first painting task but whoever did it originally stuck wallpaper on top of polystyrene, which I am now removing - however having stripped one wall and applied Crown emulsion, I am faced with large spots of the painted surface having bubbled up and cracked!
Internet search suggests this is caused by the need to prepare the plaster, even though it's been up for years ... my question is ... is this the likely cause and if so, what's best to use to prepare it before I go any further with the painting?
Some information on the Internet suggests an oil-based undercoat, others suggest a proprietary sealer of some sort ... hoping someone can give the benefit of their experience in an authoritative answer :D
 
Rub the patches down and apply an oil based primer.

This is quite common with new plaster and you normally prepare the surface by painting on watered down emulsion.
New plaster takes a few weeks to dry and if it isn't dry for the first coat you get bubbles appearing.

Bubbles can also appear over filler. Best way is to prime with an oil based primer.
 
Thanks, the plaster has been up for at least 20 years ... does that still count as 'new plaster', or were you just giving an example? :)
 
Ooooooooooh, listen to you "one of the extensions."

Think I'll retire to the west wing for a brandy and cigar old bean. What what:D;)
 
BRASH said:
Ooooooooooh, listen to you "one of the extensions."

Think I'll retire to the west wing for a brandy and cigar old bean. What what:D;)
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Don't mock ... I need to get it right before I tackle the sauna room, the gym and the library :D
 
gramps said:
Don't mock ... I need to get it right before I tackle the sauna room, the gym and the library :D
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Fnarrrrr fnarrrrrr. Get the stable lad, footman and butler to help out then.
 
They're already tied up pruning the maze.
 
Well, untie them - they'll be able to do a better job!

Been a long time since I played the P&D game as a way to earn a crust and TBH never had this problem - or rather never had to strip off polystyrene veneer and paint straight over it. IIRC, when surfaces were suspect, we used to use lining paper before a couple of coats of emulsion over the top of that (we always used Dulux emulsion since it was the best available and would give far better coverage per coat than cheaper brands, hence fewer coats! any savings made on materials were quickly chewed up by labour costs involved in the extra coats.)
 
Spooky! I've got a similar problem / project at the moment.
I ended up going for B&Q's own Plaster sealer, white bottle and about a tenner a litre.
It worked on new plaster, bare plasterboard. and 20 odd year old bare plaster too.


Its also possible that the "glue" used to stick the polystyrene has re-acted with the paint.
If that's the case strip everything off with "Nitromors" wash down with sugar soap (and rinse)
and then use an oil based primer as a base coat.
 
If you want it done right, without all the "what should I do" questions. ...just let the wife do it :-)
 
viv1969 said:
If you want it done right, without all the "what should I do" questions. ...just let the wife do it :)
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If I had one, I'd agree with that :D
 
Cobra said:
Spooky! I've got a similar problem / project at the moment.
I ended up going for B&Q's own Plaster sealer, white bottle and about a tenner a litre.
It worked on new plaster, bare plasterboard. and 20 odd year old bare plaster too.


Its also possible that the "glue" used to stick the polystyrene has re-acted with the paint.
If that's the case strip everything off with "Nitromors" wash down with sugar soap (and rinse)
and then use an oil based primer as a base coat.
Click to expand...

I wondered about the glue, it seemed to come off with the polystyrene ... but maybe not.
I think I'll try the Plaster Sealer first and hope for the best.

As for the wife ... she helps with critique rather than labour! :banghead:
 
gramps said:
I wondered about the glue, it seemed to come off with the polystyrene ... but maybe not.
I think I'll try the Plaster Sealer first and hope for the best.

As for the wife ... she helps with critique rather than labour! :banghead:
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Don't they always? :(
But I don't have that problem (anymore) either (y)

Glue, I would imagine that some residule would be left on the walls.
Whether or not it does re-act, its hard to tell,
good luck with the sealer (y)

edit, it might be worth trying the sugar soap, that does shift a lot of crap ;)
 
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No doubt whatever I try it'll be a long road to success ... never taken to decorating and I get the feeling it knows!
 
gramps said:
No doubt whatever I try it'll be a long road to success ... never taken to decorating and I get the feeling it knows!
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Oh I do sympathise, I really do!
My similar post in OoF is meant to be light hearted,
but inside I am crying, ne' sobbing :D
 
I would try sugar soap on the wall first. I pulled a load of the polystyrene lining paper off the walls in my bedroom (it was under painted woodchip), once I sugar soaped the walls the emulsion went on fine. Put a couple of coats of flat matt white before the colour and all was good.
 
Yeah, maybe try both options to avoid the grief ... hopefully!
 
Cobra said:
Oh I do sympathise, I really do!
My similar post in OoF is meant to be light hearted,
but inside I am crying, ne' sobbing :D
Click to expand...

Why ? You've got nothing better to do then watch paint dry have you :)
 
Not sure I totally understand what you are saying gramps - are you taking off the polystyrene or just the paper ?
Zinsser Gardz is the product you need to seal the wallpaper paste but I've never heard of it being used on polystyrene tiles as most would remove them before any decorating.
If you have taken off the tiles then another Zinsser product such as BIN123 (water based) or if you can bear the fumes, Cover Stain which is oil based. Tile adhesive used to be solvent based so I would imagine that you do not want an oil based primer/sealer - it might be worth asking Zinsser direct though it can take a couple of days to get a reply.

http://www.zinsseruk.com/contact/

If you have a decent trade paint shop nearby they will advise, but take along a couple of pictures to help show the problem. Also, buy your paint and tools from them - it may cost a few pounds more but will be way better quality, may need fewer coats and the tools will last longer and produce a better result..
 
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