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The Doylestown
(PA) Historical Society recently acquired a building, part of the
exterior
of which is stuccoed. About 1950 a new cinder block addition was
covered with a thick bumpy cement stucco without lath. The
original
building, ca. 1824, is stone. We would now like to create a
smooth,
sand-like
finish on the stucco. Our mason initially
suggested
that the bumps could be ground off and the stucco painted to be
compatible
with the light brown fieldstone. He thought a grinder could be
fabricated
if
none was available. Having looked into it, he has
changed
his mind and says the only alternative is to remove the stucco and
start
over - which for us would be prohibitively expensive. Any idea
how
we can otherwise
obtain our desired result ?
The secrets of sandblasting and resurfacing
the
old stucco are:
1. The surface must have at least 90% or so
of
the
paint gone and rough with open pores.
2. You must mix an acrylic admix into the
bonding
coat.
There is an old fashion way that still is
used
in Latin America,
but it is too much trouble.
We use flex-con.:
You can use a bonding coat like they say
on the
bucket
or do what we do:
cement and sand mix with 50-50 flex-con and
water
This way you can level up the rough
wall
3. We go 50-50 flex-con and water on the
finish
coat, too.
It's not cheap, but well worth the
results
4. Use at least 6 mil plastic or cardboard
when
covering windows, etc.
for sandblasting.
A tip: If you rent equipment, check
EVERYTHING
before you leave.
Including, helmet, filter, hoses, etc.
Bring
sand.
Make sure the filter on the air filter has
been
replaced recently.
5. Use this tape for windows. etc:
Don't ever use duct tape or you'll be
cleaning
glue off for weeks.
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