Gluing Plaster
Fr...@the.net
best adhesive for gluing a plaster sculpture back together? The
plaster involved is soft - perhaps moulding plaster.
CWS
Gary Waller
<Fr...@the.net> wrote in message news:46cbe84f...@news.idworld.net...
The problem, as you probably know, is that the plaster sucks up anything
with water in it, and you want the join to be as thin as possible.
I am old school, and have all these materials around - you may not. What I
would do would be to use red shellac (like Bullseye - or make your own from
flake and alcohol (this keeps the best). First brush on at least one coat,
maybe two, letting the shellac sink into the plaster and dry - then put some
red shellac in a small tin/can take it outdoors, light it on fire until it
forms a gummy, sticky paste then extinguish the flame - now brush this on,
and stick the pieces together. A nice, tight bond - but it shows a red line.
Seal the plaster sculpture with a clear varnish/sealer, acrylic is ok, brush
the statue with a bright white lime wash (lime and water) - in few years
time, when the statue starts to look grimey/dusty - wash it with a soft
brush - the lime and dirt will come off, but the sealer will not, then a
fresh coat of lime - this stops the years of builtup paint which obscures
the details and is almost impossible to remove.
Andrew Werby
[I've generally used regular white glue (technically called PVA, or
aliphatic resin - AKA "Elmer's") The trick to using it for plaster repair is
to soak the pieces to be glued in water first; this stops the plaster from
immediately sucking all the water out of the glue and making a weak bond.
Then prime the pieces with a dilute solution of the glue before using the
full-strength stuff. If you have big gaps, make up a mixture of glue. a
little water, and an inert powder (marble dust works great; don't use
plaster dust). This should be stiff enough to trowel into the gaps, but soft
enough when set to be sanded back to grade. Prime the repaired piece with
shellac afterwards, using a dilute coat before a full-strength one. After
that, it can be painted with latex, acrylics, or oil-based paints. ]
Andrew Werby
www.unitedartworks.com
Gary Waller
Both Andrew and I are recommending shellac because it is unique that it will
'dry' even on wet surfaces, and plaster is often damp when you are working
on it. There is a white shellac on the market as "Killz" - to spray on
leaking ceilings, etc - it also has white pigment in it. All shellacs are
natural, they are made from beetle wings, it is widely available on the
internet as flake, once the alcohol is in it, it is hazardous to ship, and
the price goes way up.
For those of you who know me, in the internet since anyways, will be pleased
to know that I now even make my own ethanol alcohol - I've bought a nice
still to experiment with essential oil extraction. Now if I could just find
the formula to make my own duct tape ...hmm?
Dan S
you have a clean break and perfectly-fitting surfaces you don't want to use
anything that clots up that joint. Andrew and Gary are right about how to
use their preferred glues.
I will just add that there's no great advantage to getting small flakes
exactly into place. Better to dampen the area and get new plaster in there.
I squirt it with a dental plastic syringe, cut the tip back.
I have not seen any advantage to mixing plaster with water+white glue.
Soft plaster? Like mexican stuff sold at the roadside? We call cheep plaster
"chalk" and perhaps it could use a good shellacking all over just to
strengthen the surface.
Would Kilz work as glue or is there too much solids in it?
--
Dan Spector
901 323 8717
http://www.archicast.com/Lifecast-index1.html
Robert
... Now if I could just find
> the formula to make my own duct tape ...hmm?
>
>
Duct tape is like 'The Force'. It has a light side and a dark side,
and it holds the universe together.
--
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