Tiny stone scrapes while plastering

[skygod1095]

Can anyone tell me why I'm getting rips in the plaster while plastering? As I trowel out I'm getting tiny hard bits making scars in the plaster. I don't think I'm picking up dirt or grit so was wondering if it's the plaster not being mixed well enough?

Thanks

 

[Micilin]

Is everything clean? Has the finish got damp?

 

[stevethespreader]

Can anyone tell me why I'm getting rips in the plaster while plastering? As I trowel out I'm getting tiny hard bits making scars in the plaster. I don't think I'm picking up dirt or grit so was wondering if it's the plaster not being mixed well enough?

Thanks

a few reasons why this could happening one is you are dragging hard bits from the edges onto the ceiling, the edges should be cut back with the toe of your trowel and a brush run round them,
another reason is if you have a bad batch of plaster or the plaster has got damp this will cause hard bits to form in the powder, this happened on a site once where every other bag had this so i half filled the skip up with them much to the annoyance of the site manager, another reason is you are contaminating the mix