When skimming undercoat plaster how many coats of finishing plaster do I
need to apply? I guess I need about a 3mm depth but never having skimmed
before I don't know whether this depth can be applied in one go.

Can it?


Thanks,

Graham

In article ,
Graham Jones writes:
When skimming undercoat plaster how many coats of finishing plaster do I
need to apply? I guess I need about a 3mm depth but never having skimmed
before I don't know whether this depth can be applied in one go.

Normally two coats. The first goes on as thin at you can and the
surface will be level with the most prominent points on the scratch
(under) coat. This means it can't be polished off, but it's flat for
the second coat. Then you do a second coat on top which will thus
always have some plaster thickness over the most prominent points on
the scratch coat, and can be polished off.

I have on occasion got away with just one coat, but I start with the
intention of doing two. If the first coat seems like it will polish
up without hitting any of the prominent points on the scratch coat,
then there's no need to do a second coat. IME, this is less successful
if reskimming as you need the thickness of two coats to help with the
strength -- it doesn't bond as well to the old finish coat as it does
to a new scratch coat.

--
Andrew Gabriel

Andrew Gabriel wrote:
In article ,
Graham Jones writes:

When skimming undercoat plaster how many coats of finishing plaster do I
need to apply? I guess I need about a 3mm depth but never having skimmed
before I don't know whether this depth can be applied in one go.


Normally two coats. The first goes on as thin at you can and the
surface will be level with the most prominent points on the scratch
(under) coat. This means it can't be polished off, but it's flat for
the second coat. Then you do a second coat on top which will thus
always have some plaster thickness over the most prominent points on
the scratch coat, and can be polished off.

I have on occasion got away with just one coat, but I start with the
intention of doing two. If the first coat seems like it will polish
up without hitting any of the prominent points on the scratch coat,
then there's no need to do a second coat. IME, this is less successful
if reskimming as you need the thickness of two coats to help with the
strength -- it doesn't bond as well to the old finish coat as it does
to a new scratch coat.


Thanks Andrew