Craftmanship

[Don Dougan <dondougan@xxxxxxxx>]

Andrei:

You asked not to mention American products, because you live in Germany
and couldn't get them . . .

However, I know several products are available in Italy and France, so I
assume they are also available in Germany --  specifically "Super Glue"
(I think it is called Super Attak! in Italy) or other brands of a liquid
cyanoacrylate glue.

When I have a crack or fissure in the marble and I want to stabilize it
while working I use some of this product.  It works best when there is a
small amounts of moisture in the material, and a tight fitting joint. In
the Southeast US where I live we have generally high humidity year-round
(that provides the moisture), and a fissure in the stone is by definition
a tight fit.  It does not fit gaps!

I usually just run a little of the liquid over the clean surface of the
crack or cracks and allow it to dry.  It will bleed into the crack
through capillary action and bind it together during the working process.

The residue on the surface can be removed in subsequent carving,
grinding, or sanding, leaving a fairly sound surface.
If I a doing it during the carving stages, where I am removing material
more than a couple of millimeters deep, I repeat the process to insure
sufficient depth of  penetration for the adhesive to bind the material at
the edges of the crack together and keep them from spalling or
'popping-out.'

If it is only a small surface fissure that doesn't appear to  go very
deep, I only apply the liquid adhesive after I have sanded the surface to
about 100 to 180 grit or so.

If there are small divots left by spalled areas of material, sometimes  I
will use some sanding dust from the stone to fill the hollow, then apply
a few drops of the liquid to the dust in the hole.  After it has dried
(several hours probably), it can be sanded and will appear as an
irregular spot on the stone.  The glue areas will polish almost as
readily as the surounding stone.   Depending on the type stone, the fill
may not be very noticable at all -- though obviously homogenous-colored
and fine-grained stones will reveal the blemish more than highly figured
coarse-grain stones.

Most of the time when I use the cyanoacrylate adhesive to fill fissures I
am using it on highly-figured stones which are particularly prone to
having these types of flaws -- spanish negro marquina black, spanish rojo
alicante red, italian rosso levanto dark red/green, etc.  On these stones
the touched-up areas never show.  When I use it on a homogenous white
marble, the treated flaws do show, but generally are less noticable than
if the flaws were left untreated and the surface finished the same
(usually polished or sanded smooth), and I have not noticed any yellowing
with passing years (I have been using this method for at least ten years
or more).  Larger flaws that have been filled I try to modify my design
so the affected surface area is finished with some sort of textural
treatment that will tend to downplay the differences.

Hope this is of some help -- let me know what name "Super Glue" goes by
in Germany!

 "Such a shame we can't upload pictures here, I'd love to see what
you are doing . . .  "

You can see pictures of my stuff on my website: http://www.dondougan.com

Good Carving to You,

Don