So close to a not quite perfect lime wall

[kristeva]

Hi all, a quick technical question for the experts not necessarily just about lime plaster.

When I'm floating an open textured lime finish on a wall with my sponge float it flattens and fills as you would expect but what are those really annoying hollows that occasionally appear and don't fill but in fact open up more as you float? Have I gone to far and removed plaster or are they, as I suspect, an indication that wall is not perfectly flat. And what is the fix, to continue floating back or to patch with plaster. Unfortunately my putty based plaster isn't fine enough to blend such subtle ridged hollows. Would pure lime putty create a better patch?

Apologies for the lack of photo. Any comments appreciated.

 

[StephenStephen]

I always think that lime is best with a not quite perfect finish!

How deep and wide (roughly) are these hollows?

 

[ree]

OP,
I presume that you are a DIY'er whose taken some bad plastering advice?
By and large, its best to keep well away from using putty plaster - why would you need to use it in any shape or form by itself or as an additive?
Whatever, it sounds like you could have a poor mix, and are going at it too soon for a sponge float finish?
An old spread told me that timing is everything in plastering. I dont know about that but timing is surely pretty important.

Without seeing it, knowing what you've mixed & how it was applied to what background its difficult to advise

 

[StephenStephen]

As an amateur, I couldn't disagree more with the suggestion to avoid lime putty. It's a lot slower and more forgiving than gypsum. I'm often curious why the professionals seem nervous of it.

If the plaster isn't fine enough then I'd suggest using kiln dried sand in the top coat, and yes, you can move towards having a very lime rich mix.

A couple of resources I've found useful are the videos from Mike Wye (YouTube), and Jane Schofield's booklet: https://www.blackdogpress.co.uk/product/lime-in-building-a-practical-guide-by-jane-schofield