As a mostly self-taught plasterer, I'm never absolutely certain as to
what extent my mixing proportions of plaster:water are correct. Most
times the mix is Ok but at other times it ends up too stiff. Could
someone please advise so that I can do some calibration?

What I'd appreciate knowing are optimum volume (litres) and weight
(Kg) of plaster per (say) 5 litres of water for

(1) British Gypsum Thistle Multifinish plaster

(2) Thistle Bonding Coat

Both litres and Kg would be appreciated as a cross check.

I've checked the BG web site but couldn't see anything relevant.

Thanks for any info.

On 21 Jul, 23:09, wrote:
As a mostly self-taught plasterer, I'm never absolutely certain as to
what extent my mixing proportions of plaster:water are correct. Most
times the mix is Ok but at other times it ends up too stiff. Could
someone please advise so that I can do some calibration?

What I'd appreciate knowing are optimum volume (litres) and weight
(Kg) of plaster per (say) 5 litres of water for

(1) British Gypsum Thistle Multifinish plaster

(2) Thistle Bonding Coat

Both litres and Kg would be appreciated as a cross check.

I've checked the BG web site but couldn't see anything relevant.

Thanks for any info.

As far as I recall you pour in X inches (or cm or mm as the case may
be these days) of water into a bucket and whilst stirring, add the
required ammount of whatever untill the required consistinsty is
obtained.

So, in a nutshell, water first, solids last.

In article . com,
writes:
As a mostly self-taught plasterer, I'm never absolutely certain as to
what extent my mixing proportions of plaster:water are correct. Most
times the mix is Ok but at other times it ends up too stiff. Could
someone please advise so that I can do some calibration?

What I'd appreciate knowing are optimum volume (litres) and weight
(Kg) of plaster per (say) 5 litres of water for

(1) British Gypsum Thistle Multifinish plaster

(2) Thistle Bonding Coat

Both litres and Kg would be appreciated as a cross check.

I've checked the BG web site but couldn't see anything relevant.

That's because no one mixes it up that way.
You start with a clean bucket, and fill it no more than 1/4
full of clean water. You then keep pouring in plaster and
mixing until you get the right consistency (and no lumps).

For bonding coat mixed up correctly, it will stay on the
trowel (just) when you turn the trowel vertically, but
will slide off if you give a small jerk. Finish coat is
more sloppy, and should slide off the trowel when you
hold it vertical. People who haven't done much plasting
usually mix it up much too stiff, thinking it will run
off the wall otherwise, but it doesn't.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

On Jul 21, 11:43 pm, (Andrew Gabriel)
wrote:

People who haven't done much plast...errermm...ing usually mix it up
much too stiff, thinking it will run off the wall otherwise, but it doesn't....

...if you wet the wall or if the wall is plasterboard

On 21 Jul, 23:43, (Andrew Gabriel) wrote:
In article . com,
writes:
///


What I'd appreciate knowing are optimum volume (litres) and weight
(Kg) of plaster per (say) 5 litres of water for

(1) British Gypsum Thistle Multifinish plaster

(2) Thistle Bonding Coat

Both litres and Kg would be appreciated as a cross check.


//

That's because no one mixes it up that way.
You start with a clean bucket, and fill it no more than 1/4
full of clean water. You then keep pouring in plaster and
mixing until you get the right consistency (and no lumps).

Yes that's what I do, but - big BUT - I was shown a long time ago by
someone who'd been started off by a bricklayer/plasterer but was also
mainly self-taught. So I operate in a bit of a knowledge vacuum. Much
of what I do is as a result of trial and error and inevitably things
drift. Mixing consistently and correctly is my biggest bugbear.

Plaster manufacturing must be a pretty tightly controlled controlled
process, so I assume acceptable mixing proportions should be
specifiable to quite close limits. Knowing these proportions would
eliminate a major 'unknown' and let me make occasional self-checks.

Any chance someone could very kindly note down the weights & litres
used next time they plaster & post here please? It would be so
helpful to me and, if my experience of getting going with plastering
is anything to go by, helpful to most newbie plasterers too.


For bonding coat mixed up correctly, it will stay on the
trowel (just) when you turn the trowel vertically, but
will slide off if you give a small jerk.

That's helpful, though separated from the plasterer and without
numbers it's hard to be certain we see the same thing.

Thanks.

In message . com,
writes
On 21 Jul, 23:43, (Andrew Gabriel) wrote:
In article . com,
writes:
///


What I'd appreciate knowing are optimum volume (litres) and weight
(Kg) of plaster per (say) 5 litres of water for

(1) British Gypsum Thistle Multifinish plaster

(2) Thistle Bonding Coat

Both litres and Kg would be appreciated as a cross check.


//

That's because no one mixes it up that way.
You start with a clean bucket, and fill it no more than 1/4
full of clean water. You then keep pouring in plaster and
mixing until you get the right consistency (and no lumps).

Yes that's what I do, but - big BUT - I was shown a long time ago by
someone who'd been started off by a bricklayer/plasterer but was also
mainly self-taught. So I operate in a bit of a knowledge vacuum. Much
of what I do is as a result of trial and error and inevitably things
drift. Mixing consistently and correctly is my biggest bugbear.

Plaster manufacturing must be a pretty tightly controlled controlled
process, so I assume acceptable mixing proportions should be
specifiable to quite close limits. Knowing these proportions would
eliminate a major 'unknown' and let me make occasional self-checks.

Any chance someone could very kindly note down the weights & litres

You'll never get that

At the end of the day, it comes down to a matter of feeling, an
appreciation of what feels right, intuition

reduce it to bare figures and you'll not get it right

Well, you might, but ...


--
geoff

In article ,
raden writes:
In message . com,
writes
Yes that's what I do, but - big BUT - I was shown a long time ago by
someone who'd been started off by a bricklayer/plasterer but was also
mainly self-taught. So I operate in a bit of a knowledge vacuum. Much
of what I do is as a result of trial and error and inevitably things
drift. Mixing consistently and correctly is my biggest bugbear.

Plaster manufacturing must be a pretty tightly controlled controlled
process, so I assume acceptable mixing proportions should be
specifiable to quite close limits. Knowing these proportions would
eliminate a major 'unknown' and let me make occasional self-checks.

Any chance someone could very kindly note down the weights & litres

You'll never get that

At the end of the day, it comes down to a matter of feeling, an
appreciation of what feels right, intuition

reduce it to bare figures and you'll not get it right

Well, you might, but ...

Plaster is heavily based on natural products which are going
to vary, and it significantly changes as it ages in the bag.
I doubt there is a one-figure-fits-all value.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]