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 ?
WARNING ! WARNING ! Larsen's plaster weld is made for interior use and dissolves in water. It will fail if used outside. Plaster weld even says on the bucket for interior use, and not for use in wet areas such as showers.
We scraped this stucco off in about 10 minutes. It was loose and popping off the wall. The pink plaster weld was made for interior use. Whenever you see stucco popping off and it is pink underneath, it is plaster weld or a bonding agent used for interior use. If it is blueish it is Sta-dri link, which always fails. If it is blue, it is weld-crete. Even though weld-crete is made for exterior use, it fails often. Weld crete doesn't work well on a painted surface. It is embarrassing for me to admit, we used Weld-Crete many years ago for stucco and it is all popping off the wall.
The practice of using these paint on bonding agents still goes on here in the Washington area and needs to stop.
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. Our chipping and bonding method works good, by chipping the wall every few inches back to the basecoat. Then a bonding coat applied by mixing acrylic like Flex-con 50-50 with water, portland cement and sand. A thin coat is then applied 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 applied.
