CONTRIBUTORS | PAINTING
Painting Over Old Applications
DEAN NAGATOSHI
Hawaii’s aging buildings require testing to find the proper primer and paint
H
awaii’s older buildings have more than likely received multiple coats of paint over the years. This causes a buildup of layers that can peel from the surface like the layers of an onion. Sometimes it can be the failure of the primer from the previous painting project, or the failure of the primer from the original painting project that was done many years ago when the building was built. Existing paint failure can also occur where no peeling of paint is present. After the application of the new paint
system, paint blisters could occur due to the added stress, weight and thickness of the new paint being applied over old paint. Surface preparation to remove peeling paint and paint that has not yet peeled (but is no longer adhering to the surface) can be quite costly. I recall a project where the existing paint was very weathered and chalky, and there was a concern that the new paint system might not adhere to the existing paint. To make thing more complicated, since it was an older building, the existing paint was tested
and determined to be lead-based. The specification called for surface preparation to clean the surface and a primer that was specifically designed to go over chalky painted surfaces. A paint adhesion test was requested, revealing that that the specified primer would not adhere to the prepared painted surface. Several samples were then made with various methods of surface preparation that would not generate dust due to the lead paint. Also, different primers were used to determine which would provide the best adhesion. Additional adhesion tests were
Your Resource for Painting and Decorating Contractors PDCAH
awa i i . o r g
PDCA of Hawaii Contractor Members • • • • • • • • • • •
Akira Yamamoto Painting, Inc. BEK, Inc. Hirota Painting Co., Inc. Honolulu Painting Co., Ltd. Jade Painting, Inc. J.D. Painting & Decorating, Inc. Metropolitan Painting & Environmental Systems, Inc. M. Shiroma Painting Company, Inc Society Contracting, LLC W.E. Painting, Inc. Zelinsky Company, Inc. PDCA of Hawaii P.O. Box 22597 | Honolulu, HI 96823-2597 (808) 479-6825 | info@pdcahawaii.org
34 BUILDING MANAGEMENT HAWAII | SEPTEMBER 2020