Sealer/undercoat for "white set"

[prof_montoya]

What is a good sealer/ undercoat to use on fresh "white set" walls and plaster patches? I've read the back of sealer/undercoat paint tins and only a few are suitable for hard plaster and they are not water based. Thoughts? Thanks.

[Slobba]

white set ? are you talking solid plaster ? but plaster patches either an acrylic PSU, solver maxi prep, dulux 3 in 1 ...stick to a top shelf brand and label...dulux also have a 3 in 1 oil based product which seems good and flows on nice and you can use a acrylic paint for a top coat

[prof_montoya]

Hi Slobba,

Yes I am referring to solid plaster. Some of the walls in my house are being fully re-plasterered. Others are just having cracks patched (with cornice cement). I know that many acrylic sealers are not recommended for solid plaster. Dont know why. They are recommended for wood, (cardboard faced) plaster board, etc, but not for solid plaster. I've only found a few oil based sealers that are suitable. I am wondering if anyone out there has any recommendations or other views.

Thanks

[Slobba]

allow new unpainted surface to cure and dry for at least 12 weeks. adhesion problems occur if the correct sealer is not used. this can be attributed to poor troweling or the addition of air entraining agents to the base coat to assist in application of the plaster set.

Water based
1st coat solver line 4129 wall sealer * solvent based
2nd coat solver line 4103 all purpose undercoat * solvent based
finish coat ..solver line 4562 Maxi Wash flat or low-sheen acrylic

Solvent based
1st coat solver line 4129 wall sealer * solvent based
2nd coat solver line 4103 all purpose undercoat * solvent based
finish coat ..solver line 4171 int/ext high gloss enamel or semi-gloss

you can use a normal sealer/undercoat over the cornice patches

[prof_montoya]

Slobba - Thanks for your response. I want to avoid solvent based undercoat.

Have you (or anyone else) used Rockcote acrylic sealer/undercoat on solid plaster?

http://www.rockcote.com.au/technical/ecosealer.html