Selected Answers

From Rodney White of Independent Consultant on January 19, 2015:
It depends. Where is the structure with the failin ...read more It depends. Where is the structure with the failing coating? Outside in an isolated area? Inside the corridor of a busy school? There are many effective methods that can be employed to remove failed coating and leave the underlying " intact" coating undamaged. One might employ the sponge blast mentioned by Robert, on the exterior of a building, but if the failure is in a school corridor, one might be limited to scraping and brushing to remove the failed coating, and the possibilities go on. . . .

From kevin sharman of QIC Protective Coatings Pty Ltd on January 16, 2015:
Use a broom or hand brush. ...read more Use a broom or hand brush.

From john schultz of o-gee paint co on January 15, 2015:
Given that there is loose coating material on the ...read more Given that there is loose coating material on the surface, there is little to give confidence about the durability of the "intact" coating. The idea is to direct enough energy at the existing surface to stress it, to throw ten years of energy into a few seconds so anything that would fail in that future is going to be removed. That said, common practice is to use cold water pressure cleaners with a rotating tip moving in even smooth passes covering 1/2 of the previous course. Even then, scraping tends to follow as water- sensitive, under-materials soften and additive surface tension in primer coats reveals disbonded layers. Anything after all that could be considered intact.

From robert conn of GATX on January 13, 2015:
Sponge blast or CO2 (dry ice) blasting will work i ...read more Sponge blast or CO2 (dry ice) blasting will work in some applications.

From Chuck Benesch of Anchor Paint on January 12, 2015:
Use power washing to 5,000 psi or soda blasting. ...read more Use power washing to 5,000 psi or soda blasting.