Stain Block advice

[whatknot]

We live in an old chapel now 175 years old, where it appears some of the original plaster is still on the inside of the outer walls

When we moved in it was wallpapered but after a couple of years we took that off and thats when the problem occurred of staining

It will go with a spray bleach and wipe over but a month later its back, you can tell where they have replastered patches as theres no stain on certain sections

I have tried various things, lastly Zinsser Bulls Eye 123

This seems to have worked on one wall but not on two others

Short of hacking the old plaster off and starting afresh, has anyone got any suggestions for a stain block that actually works?

 

[eribaMotters]

You could try 50/50 pva and water, then follow up with any cheap oil based undercoat. I've used this method to block water stains from leaks into a lathe and plaster ceiling.

Colin

 

[Ollie78]

Tikurilla Otex oil based adhesion primer.

 

[whatknot]

Thanks for thta suggestion, not cheap is it, over twice the Zinsser I used and that was supposed to be the bees knees


Tikurilla Otex oil based adhesion primer.