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https://www.askthetrades.co.uk/cgi-bin/yabb/YaBB.pl DIY Forum >> Painting, Decorating & Tiling Questions >> Stain block https://www.askthetrades.co.uk/cgi-bin/yabb/YaBB.pl?num=1246535025 Message started by Zambezi on Jul 2^nd, 2009, 12:43pm

Title: Stain block
Post by Zambezi on Jul 2^nd, 2009, 12:43pm

A property I need to do some work in has water stains on some walls, from penetrating damp (failed pointing). I have sorted the pointing and now want to touch up the emulsion on the effected areas indoors.
Should I use a stain block paint first? Will something like Johnsons Alkali Resisting paint work? Should I just touch up with emulsion and hope the stain does not bleed through?
Ta,

Title: Re: Stain block
Post by Twobarrows on Aug 4^th, 2009, 9:50am

Try ZINSSER B-I-N Primer-sealer stain killer. It's a shellac base sealer that dries in 15 mins & can be recoated in 45 mins! It's horrible to paint with as it dries so quick, it also dries on your brushes quick & can only be cleaned off with Meths, so disposable brushes would be a good idea.
It's not cheap, about £13 litre, available from BNQ, and it does the job!

Title: Re: Stain block
Post by Zambezi on Aug 4^th, 2009, 2:16pm

Ta, I will keep an eye out for it.

Title: Re: Stain block
Post by woodsmith on Aug 4^th, 2009, 7:25pm

Can you paint matt emulsion over the Zinzer BIN?

Title: Re: Stain block
Post by Twobarrows on Aug 5^th, 2009, 9:48am

woodsmith wrote on Aug 4^th, 2009, 7:25pm:

Can you paint matt emulsion over the Zinzer BIN?

'Use with all paints' it say's on the tin. I painted it on a new wall in the bathroom & overpainted it with Dulux b'room paint.
It can also be used as knotting, which is nice as it's white!

Title: Re: Stain block
Post by woodsmith on Aug 5^th, 2009, 5:46pm

Thanks, the reason I asked is that I've recently discovered you shouldn't paint matt on top of silk or gloss emulsion.

Title: Re: Stain block
Post by hammy on Aug 6^th, 2009, 4:38pm

Really if you must paint matt emulsion over silk it's best to really rub down the silk to provide a 'key'.

Putting flat paint over shiny paint is not too good, shiny over matt, not so bad.

What's all this about 'gloss emulsion' Woody, it's a new one on me. :-/

Title: Re: Stain block
Post by woodsmith on Aug 7^th, 2009, 6:57am

hammy wrote on Aug 6^th, 2009, 4:38pm:

What's all this about 'gloss emulsion' Woody, it's a new one on me. :-/

What, I'm surprised you don't use it all the time :P

You are, of course quite right, I meant gloss paint or silk emulsion :-[

Title: Re: Stain block
Post by Twobarrows on Aug 7^th, 2009, 2:54pm

wrote on Aug 5^th, 2009, 9:48am:

woodsmith wrote on Aug 4^th, 2009, 7:25pm:

Can you paint matt emulsion over the Zinzer BIN?

'Use with all paints' it say's on the tin. I painted it on a new wall in the bathroom & overpainted it with Dulux b'room paint.
It can also be used as knotting, which is nice as it's white!

And the reason I was using it in the first place, was that the bathroom paint peeled off! It was like wallpaper, I've never seen anything like it in my life.
The walls had had a fresh skim (2 coats) of plaster about 2 or 3 weeks prior, then a VERY wet & messy mist coat with about 20-25% water added as it was very hot at the time. Next a coat that was probably about 10% thinned, then a finish straight from the tin. The paint was ICI/Dulux Bathroom paint (with the little yellow duck on it), which I have used loads of times before.
After the tiling (I painted before the tiling as the mist coat is so messy) I taped over the plastic edging & a bit of wall with masking tape to keep it clean from grout. As soon as the grouting was finished I removed the masking tape..........and most of the paint! I had sheets of it hanging over the shower door!
I contacted the ICI/Dulux Customer Advice Centre & spoke with a very helpful young lady who asked me to send in a sample.
Today I got the feedback that it was nothing to do with the paint, but as a goodwill measure they would compensate me with 5l of a paint of my choice.
I'm more than happy with the the result, but am curious as to what others would have done for priming / mist coat?

Title: Re: Stain block
Post by Zambezi on Aug 7^th, 2009, 9:57pm

I probably would have done the same as you TB, except I would have used Wickes paint because it is half the price ;D

Title: Re: Stain block
Post by hammy on Aug 8^th, 2009, 1:55pm

I think I would have done the same as you TB.
You waited two or three weeks for the plaster to dry out, no problem there.

You thinned the mist coat well so it would sink into the plaster, OK.
Subsequent coats, OK.

I would hazard a guess that when the paint came away from the plaster that it came clean away and left the original bare plaster, ie, the mist coat came off as well.

If that is the case it suggests to me that the plasterer has shone the plaster up to a hard finish and as thin as it was, the mist coat just sat on the top rather than soaked in.

Paint's OK. Your painting's OK.

Find the plasterer and kill him.

Title: Re: Stain block
Post by woodsmith on Aug 8^th, 2009, 2:54pm

Ahh, now that makes sense, thanks for that Hammy. I have a few rooms to emulsion and I have become paranoid of late that the paint will just peel off, now I know what to look for. [smiley=thumbsup.gif]

Title: Re: Stain block
Post by londonman on Aug 8^th, 2009, 10:58pm

Over-skimming can cause your problems, TB. By that I mean the plasterer going over and over and over the final skim layer.

Title: Re: Stain block
Post by Twobarrows on Aug 9^th, 2009, 11:40am

hammy wrote on Aug 8^th, 2009, 1:55pm:

Find the plasterer and kill him.

Much as I like a good punch-up, this may be a bit of a problem as he is a tonking great ex para who used to coach the para boxing team!He doesn't go down easliy!
He's also my father-in-law, and it is a free job so I can't ask for my money back:-)

Title: Re: Stain block
Post by Zambezi on Aug 10^th, 2009, 7:45pm

Give the walls a rub with some sandpaper, wipe off the dust and start again...