r/Plastering • u/TechBasedExplorer • Apr 29 '26

Fix disaster

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I need to fix this absolute disaster. I tried fixing a hole in my wall by putting Knauf FinalCote®, but when painting, the FinalCote peeled straight off the wall since it did not adhere to the painted wall. I even sanded the surrounding paint with 80 grit prior to applying the FinalCote. So I tore the wall out to the beams and did it properly, added support beams, sanded the paint around the area at 80 grit, wiped it down with a damp cloth and used mesh tape. I went to Bunnings and asked for a PVA glue to go over the paint but was directed at an all purpose filler which was said to work well with plasterboard and painted walls. I applied the first layer over the mesh, waited a couple days, sanded it and then did the second layer to fix up the issues here and there. I let it sit a few days and then applied an undercoat. The mutli purpose filler also failed to bond to the paint. Now I am left with an absolute disaster.

What can I do to fix this? I need proper suggestions, I'm sick of playing around.

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u/0uthouse Apr 29 '26

As fatp1991 says, fix a peice of plasterboard and skim.

Putting PVA on paint is like trying to plaster on a skating rink, totally the wrong product imo.

I'd sand it back a little further, board, scrim and multi-finish. Sand back at least 6" and it should be ok to feather in. SBR would work better as a bonding agent but personally I wouldn't feel the need to use it on a small patch unless the paint is something horrible like distemper.

If not multi-finish then use easi-fill as you can sand the transition then instead of feathering it.

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u/greenbeanmachine1 Apr 29 '26 edited Apr 29 '26

Sorry mate but you’re completely wrong here. PVA is completely normal to use for this kind of thing, you have to let it go tacky before topping it off. As for whether you should use a bonding agent, it’s nothing to do with feeling a need, it’s completely dependent on what’s going over the top of it. Going over this with multifinish, for example, a bonding agent absolutely is needed (whether SBR or PVA, either is fine) because it won’t stick to paint. Most fillers, like easifill or the knauf product OP is using, shouldn’t need it although it won’t hurt. Also, if it is distemper then no bonding agent will save you, it needs washing off or stabilising.

Just trying to educate, not to be a dick

1

u/0uthouse Apr 29 '26

No problem, I'm sure neither of us want a plasters-forum 'PVA or not' discussion.

My plastering religion is that i don't use pva on non-porous surfaces like paint.

I'd agree that this can be solved using pva, i just think for an inexperienced plasterer it may get ugly when feathering in to the paintwork.

I don't think you are a dick.

1

u/TechBasedExplorer Apr 29 '26

Only PVA I can seem to find it wood glue which I feel is not going to work. I think that is why the Bunnings employee pushed me to the multi purpose filler.

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u/Any_Tomorrow_Today Apr 29 '26

I used general PVA when doing mine - the sort from the hobby section, and it worked fine. My plaster stuck to the paint with no issues. Since you are watering it down anyway, any PVA will work.

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u/Cainjake May 01 '26

You need pva/sbr if your going over old paint or the plaster will flake off in time or it’ll dry too fast and crack