Bali Frieze

["Simon Brown" <moonsong@zzzzzzzzzzzzzzz>]

John,

It is difficult to advise without seeing the material, but I have achieved
good results in patching sandstone (that is crack repair, not
reconstruction, a separate process) using either of 2 methods, depending on
the urgency of the situation and the size of the crack.

If a small piece of stone is chipped off a corner and is a fairly clean
break, I use Supa-Glue (cyanoacrylate adhesive- be careful!) to fasten the
piece back on and repair the crack by adding the glue to the surface and
rubbing with the same material. It dries very fast, so as you rub, the dust
produced is mixed with the glue, fills the crack and dries invisible. This
has been handy when a client is hovering nearby! I have used this glue for
building stones exposed to sun and rain for the last 10 years, and still
can't find them even if I look carefully.

If I can repair a patch and leave it overnight, and if it is a hole or large
crack, I have used an acrylic sealer mixed with sandstone dust and fine sand
that is rubbed back the next day. The dust is obtained by drilling similar
material and catching it in a box held underneath, then mixing with the
sealer. The sealer tends to darken the dust, so I add an equal amount of
fine white beach sand to lighten it. I use a 'natural look' sealer that
dries invisible. The crack is wet with the sealer, and the dust, sand and
sealer paste worked into it. The crack is overfilled with the paste and left
to dry overnight. Next day I rub it back with a wet 120 grit carborundum
stone and sponge clean. I have also used mortar additive 'Cemstick' (not
Bondcrete or other latex - it is too rubbery) instead of stone sealer with a
good result. You may need to experiment with different sands to match colour
and texture.

Simon