Unusual pattern when plaster drying - causes issues when mist coating

[Jacklev94]

Hi,

We recently had our 1930s house replastered throughout and noticed some patches appearing through the mist coat. It’s been 5 weeks since the plastering was complete and appears to be totally dry.
When painting the issues seem to be where the plaster has some patterning as the attached pictures will show. There are areas where it’s completely fine and the mist coat covers without issue but there’s also a lot of patches on the plaster as per the pictures.
Any advice would be much appreciated!
Thanks

 

[JohnD]

it's often PVA adhesive on the surface, but yours looks to me more like watery slurry where the plaster was polished.

do you have any unpainted plaster, that you could experimentally rub with a coarse, damp old towel or other rough cloth?

 

[Alastairreid]

Its called tiger stripes.

If you one coat or trowel up too early, use too much water when trowelling up.Or apply too much pressure when flattening can also cause them.

 

[albaPhenom]

Any plastering I’ve had done looks similar, painted up fine after a mist coat.