On 31 Jan, 20:00, "Phil L" wrote:
mushymanrob wrote:

hi

im a pretty practical bloke, i can turn my hand to most things. so im
trying to master plastering as ive no money but have time on my hands!
(im renovating my house).

i started yesterday after purchasing a 'ragni' plastering trowel from
b&q. i also got a whisk and bucket. i had no trouble mixing the
plaster (thistle multi finish , b&q) and got it to the correct
constituency. it went on pretty easy, or so i thought! this morning
its dry, and theres of little ridges and little depressions in the
surface. i thought i had smoothed it off correctly but it seems not.

q) how can i remedy this? a layer of pva (dialuted 5:1) plus a further
skim?

You can do that if you like, sure beats the hell out of sanding it all down.



q) how do i avoid this? what am i doing wrong? or is it just down to
learning how to use my trowel correctly? does the trowel need a
sharper edge on it? if so.. square? or beveled?

hope someone can help.... thanks in anticipation .

The ridges are there because you trowelled it up too soon, IE the plaster
hadn't set enough...plastering, like anything else is easy if you follow a
tried and tested method:
Get the wall ready first, don't start mixing until you have done this...PVA
over everything, except plasterboard, you can apply the skimming while this
is wet or dry....if the wal is p-board, get it scrimmed up all along the
joints and make sure no nail/screw heads are proud
1) mix
2) get a coat of plaster on the entire wall, don't bother about any marks,
lines or anything else, just make sure the entire surface is covered fairly
evenly (even as in the same thickness - don't have it a mm in one part and
half an inch thick elsewhere, unless this is unavoidable.)
3) have a brew, wash your trowel, bucket etc and clean the mixing bucket
4) 10 mins later, do another mix, half the size as the first mix.
5) apply this t-h-i-n-l-y over the now partially set first coat, you are
only really using the new mix to fill any hollows and you will see that it
is much smoother already than the first coat.
6) wait 10 more mins when you've finished the 2nd coat, then with a clean
trowel and clean water, splash a small amount of water on the upper left
section of wall and work your way L-R, then the same at the bottom. (the
handle side of the trowel should be kept clean at all times, if any bits of
plaster are visible when looking down at the blade, clean them off, have a
wet brush and bucket at all times when plastering).
7) repeat number 6

Some people attempt to do large walls in one coat, but it's false economy,
firstly, it saves them 75p worth of plaster, but they spend longer trying to
get a decent finish on it, and secondly, because they think they are saving
time by 'not doing it twice', instead they end up going over it a dozen
times trying to get it right, whereas with the method mentioned above, it
gets two coats, laid down once and finally polished, but there's less effort
goes into those 'four times over' than 'one coat and struggle for
hours'...the end result is a smooth finish suitable for painting, if the
walls are to be wallpapered and it's your own house, you can leave the final
polishing, but for the sake of an extra 30 mins easy work per wall, it's not
worth leaving.

Congrats on the Ragini BTW, excellent trowels...you can rub the sharp
corners off on a brick if they are giving you too much grief, just make sure
there are no 'burrs' on the face of the trowel side...they only need half a
dozen scrapes on each corner, just to take the sharpness out.


Phil do you mind if I or you repost this on the wiki?

http://wiki.diyfaq.org.uk/index.php?...ecial:Allpages

For the OP, one other tip: if you use lime plaster you've got far more
time to work it to get it flat.


NT