Lime skim over lime

[Roger H]

What level of success have people had skimming lime over an existing lime plastered wall? In this instance, great chuncks of the top two coats of lime have come off where tiles were removed from a bathroom (super strength tile adhesive :? ). I am patching the larger voids with a scratch coat but really need to unify the patches with the general plastered areas.

Should I score the surviving top coat of lime to give the new top coat a key or attempt to feather in my patches? Any suggestions appreciated.

 

[livias]

That depends on how much of a perfect finish you want. If you want it perfect then scratch up the old lime and skim the complete wall.

If it is only a few holes and/or you live in a rustic house where a bit of patching is part of the character then fill in the gaps. Don't feather it in because the thinnest bits will have no strength and will flake away, instead butt up the new plaster to the old plaster and use a busk to be sure that the join between the two is flush. Here is one I found in the internet
http://www.specialplasters.co.uk/index.php?_a=product&product_id=73
or perhaps you could improvise. You will need to spend a bit of time getting a good edge to edge finish. If your old lime plaster has two or three coats then do replicate that. Set an electric fan going in the room so the new plaster gets enough airflow to set properly.

Anna