Plaster bonders in the UK

It's just PVA + water. They even provide you with an MSDS which says so!

Buy this:

and dilute it in water, about 1:3 pva:water.

No, that sounds like a good plan.

Cheers. I would just go with the PVA bonding (we used that on the brickwork for the other plaster), but the plasterer that we got to do the bottom metre (a kind of friend of the family) said that PVA wouldn't do for the top, it needs to be a plaster bonder that reacts with the plaster (obviously there's no scoring for it to grip to). Unfortunately he couldn't recommend a source (or even remember a brand name).

The PlasterWeld faq says "applied as a liquid and as it dries to a thin, flexible film, it forms a tenacious bond to the structural surface. The dry film is reactivated by the moisture and chemical reaction that occurs as the new plaster dries. Full bonding strength is achieved after the new plaster has completely dried."

I think that's the sort of thing I need?

Tim

Erm, maybe I wasn't clear. PlasterWeld *IS* PVA. Same stuff.

Sorry, you were perfectly clear, and I'm quite happy to accept that any confusion here is on my part (although I would have expected "our plasterer" to be more knowledgable on the subject).

So you're sure a skim of plaster would adhere fine to unscored paint\plaster covered with 1:3 pva:water? I know you've said as much but I want to be careful if I'm not using something that explicitly specifies that's what it's purpose is...

Tim

It could be that your plastere meant a different type of product - perhaps you could get him to give an example of the product he meant.

Yes - we did this in several of our rooms, and it worked great.

I can understand your caution.

My reaction was just use PVA, too - never heard of this stuff.

However, looking at the data sheet, the recipe also contains glycol butyl, benzyl phthalate and "other components are ... ... trade secrets"

I haven't a clue what these other chemicals do, but might they not be crucial in distinguishing Plasterweld from raw PVA?

David

Maybe, but don't guarantee it... - once "my plasterer" (make that "former plasterer"!) told me I should prime my newly-skimmed plaster with dilute PVA prior to emulsioning, rather than using diluted emulsion as I always had done in the past - result was that it sealed the surface and the new emulsion just kept peeling off: an unmitigated shambles!

David

================= I don't know anything about plaster bonder but I think you would probably make a much better job by repairing the existing plaster rather than trying to skim over an unsatisfactory surface.

Use a paint stripper (e.g. Nitromors) to remove the old paint and then use a combination of filling and sanding to achieve the required finish.

Cic.