To PVA or not to PVA

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TonyWig

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Stripped wallpaper from lounge walls. Under this was old emulsion over plaster, some emulsion came away with old paper leaving bare plaster. Having now filled and sanded I am ready to prepare the wall for re-papering. Advice from local major DIY store "specialist" was to use a 50:50 mix of PVA and water as a primer then an emulsion coat THEN paper.
Having read this forum and other advice I am now concerned this advice may be less than correct.
I need to stabilise the old emulsion and bare plaster (and newly filled areas) but no idea what the best way is.

Any advice most welcome thank you.
 
Not PVA

I find emulsion, starting with a mist coat, gives a nice surface for papering. I prefer walls with silk as they have better slip.
 
Not PVA

Not Silk Emulsion this contains PVA as a binder .

Matt Trade Emulsion (White) then Size walls using paste size
 
Easier to give a coat of Zinsser Gardz. this will bind the surface prior to papering or painting.
 
as bosswhite says.
I just don't get the obsession everyone has with all these Zinsser products, don't get me wrong I do use some of them and they are very good especially for problem substrates, but they are expensive and I just don't get the trend to just reach for them as a matter of course.
We used to manage before, it was called prep work, if it was loose or flaky you scraped it off, if it was rough you sanded it down if it was dirty or greasy you washed it. Not sure if it's time saving or laziness that's the motivation.
 
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If I'm papering, even on new plaster, I go for a wall paper paste size to seal the wall, and then do another size coat just as I'm papering.
 
Bosswhite said:
Is that because it contains PVA ???
Click to expand...

No. Gardz iz an acrylic resin which does not contain PVA.

On the subject of PVA, it is not strictly the PVA that we use as an adhesive/sealer that is used in vinyl/latex paints. In most instances, PVA - Poly(vinyl acetate) is used, but first has to be combined with Poly(vinyl alcohol) to create a copolymer - Poly(vinyl alcohol-co-vinyl acetate) - in order for it to be compatible with the solvent within the paint, which contains poly(methyl methacrylate).
Without these polymers/copolymers working together, we would have a paint which would not mix or dry properly.

This is the reason why I try to encourage people to avoid adding standard PVA to water based paints when they are hoping to make it tougher/adhere better - in many cases, the PVA can either ball up in the paint and cause a problem, or it will not dry correctly.


As for the comment on Zinsser products, I have to admit that I do tend to plug them quite a bit on here, but for very good reason.

Having spent years doing things the 'old fashioned' way, I certainly understand the argument for not using the products and just using elbow grease. However, as a professional decorator, it more than makes sense to use them as much as possible - financially, physically and timewise, in order to provide a competitive professional service, and I was happy to see them arrive.
They are only truly essential products in some problem cases because, for those doing DIY, there are usually no time/labour constraints meaning money saving is a valid point, but, if they can solve a problem quicker, why not use them?

The main reason I, and many others, recommend them here is purely to make life easier for the person who is looking for help/advice - who doesn't want to make tedious tasks as easy as possible for themselves?

It does surprise me that Zinsser seems to have cornered the market with these 'problem solving' products, and I often wonder why other manufacturers haven't cottoned on that there is money to be made by producing similar products of their own. I suppose competition would drive prices down, meaning profit margins wouldn't be as high, but it doesn't seem to stop other markets copying each other.
 
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Yep I fully understand using them in those scenarios but its about assessing the situation and using appropriately. Our trades are going down the route of labour saving methods which don't consider the long term view. So instead of working to get those last tiny bits of paper off or spending a couple of hours washing paste residue off, you spend £120 and zinnser the lot. Part of prep is about ensuring that future jobs can also be carried out successfully not just the one in hand. has anyone tried stripping gardz off yet. We pile all these products on without giving consideration to what we do when/if they become the problem substrate them self.
As a decorator you know full well that if you paint over a hair and then put coat after coat after coat of paint over it, the imperfection doesn't blend into the paint , it gets bigger and bigger
 
misterhelpful said:
It does surprise me that Zinsser seems to have cornered the market with these 'problem solving' products, and I often wonder why other manufacturers haven't cottoned on that there is money to be made by producing similar products of their own. I suppose competition would drive prices down, meaning profit margins wouldn't be as high, but it doesn't seem to stop other markets copying each other.
Click to expand...
Doesn't surprise me . Zinsser = American. Harley Davidson=American, the Yanks are just good @ selling to us $1 for £1 and telling us how good their products are.:sneaky:
 
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