Bonding agent
failure.
I am an attorney in Miami, Florida dealing with a
stucco delamination
issue
on a hotel in Miami Beach. I need a stucco guru who can
communicate
to
ordinary people. Are you aware of any delamination
problems
caused by
exterior use of Larson Plasterweld, Lambert Bondrite Liquid or
Florida
Laboratories Chemweld.
Chemical bonding agents (paint on type), painted on over painted stucco and
sometimes
porous unpainted stucco will fail
over time. Work we did this way
years ago is all loose and
popping off.
By the time I got back with my camera,
this wall was already torn
off.
Plaster
weld was painted on the old painted stucco and
the new layer
of
stucco was loose and popping off.
It is real embarrasing to think we used these bonding agents years ago,
and all the work we did is loose and popping off. I stopped using these
bonding agents when I discover work we had done 10 years before
was already failing. I felt we were doing the customer a service
by
saving money. All I can say is I'm sorry, I just didn't know, even
though
it is a frequent practice to use them.
The practice of using these bonding agents still goes on here in
the
Washington area and I'm sure other places. If you are a plasterer
using this method, I suggest you stop immediately. I have seen
buildings around Washington that are pink(or blue) with bonding agent
and the stucco has popped off, or was scraped off. Pretty sad for
what should be a permanent application. If you want evidence,
write
and I'll send you addresses you can ride by and see.
My solution to recoating painted
surfaces or old stucco is to use an
Acrylic bonding admixture, but first removing the old paint, at least
90
per cent. Then a bonding coat applyed by mixing acrylic like Flex-con
50-50 with water, portland cement and sand. A thin coat is then applyed
leaving the surface rough by using a float, combing with a trowel or
even a brush. After the bonding coat sets at least overnight, a finish
coat
can be applyed.
Here a bonding coat is applyed after the failed stucco
and coat of the paint is scraped off.
There are other methods of appying a bonding coat, such as
mixing
pure acrylic with portland cement( no sand) and applying with a stiff
brush or a broom. The important thing is that the surface is left rough
with open pores for a good bond with the finish coat.
These bonding agents are excellent for indoor plastering, they
eventually
fail on the exterior because rain will eventually soak into the stucco
and dissolve them.
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