PAINTSQUARE BLOG

Typically, the two biggest costs for projects involving abatement of hazardous paint on complex structures are access and containment. With such substantial investments (and financial exposures if something goes wrong), you need to spend just as much, or more, time and effort planning your containment and access for the workers inside it as you do figuring your production rates, paint consumption, and equipment costs.

Images: Washington State DOT, CC BY-NC-ND, via Flickr

Focusing ahead of time on how you will efficiently raise, lower, move and seal the containment around the various phases of the structure will pay off with big dividends.

I don't know if your experiences are the same as mine, but it always seems that on the day of the bid walk for that big power plant structure, refinery unit turnaround or bridge repaint, it's a bright, clear, sunny day and you're concentrating on the challenges of the structure, the paint system, and the adjacent properties. However, when it actually comes time to do the work, it's been raining (or snowing!) for days, the ground is a muddy mess, high winds are forecast and you wonder what you were thinking when you put in your bid!

Considering the inevitable impacts of wind and weather, and focusing on how you will efficiently raise, lower, move and seal the containment around the various phases of the structure will pay off with big dividends.

Size Matters

For convenience's sake, you may be tempted to enclose as large an area as possible, so the greatest square footage at a time can be cleaned and painted. This is usually a very poor idea. First, large areas are difficult to effectively ventilate. Not only will your crews be exposed to more hazardous dust and debris in the air, you may run afoul of SSPC and OSHA requirements and have poor visibility as well. If your blasters can't see their progress, they can’t efficiently clean the steel.

Secondly, large containments put more stress on the structure and can risk exceeding contract load limits or even damaging the structure, plus big areas of containments are more susceptible to damage themselves from high winds. Believe me, you don't want to have to deal with explaining where all the contaminated abrasive went when your containment blows apart. Modular, sequential containments are usually a better way to go.

For convenience's sake, you may be tempted to enclose as large an area as possible,, but modular, sequential containments are usually a better way to go.

Effective containments include, or at least allow for, effective access to all the areas that need painting. The ideal solution may be a moveable platform that provides ready access and can be enclosed to provide containment as well. Occasionally the master containment will have smaller access platforms that move around within it, but both access and containment should be designed together.

Go Ahead and Vent

Ventilating your containment will be a challenge. Sometimes it's more effective to have a dividing barrier within the containment so that all the volume of your dust collectors can be channeled through a portion of the enclosure, keeping linear flow rates high. The other portion(s) of the containment can be used for preparatory work or for subsequent painting operations, and still be protected from inclement weather or adjacent cleaning operations.

Don't forget about access into the containment and how doors or entrances will be effectively sealed. Airlock vestibules with double doors can be very effective for preventing fugitive emissions, maintaining continuous airflow and providing an area for vacuuming off contaminated work clothing.

Plan Ahead

Partnering with an engineering company that knows your work and needs and a scaffold/platform supplier your crews are familiar with can help avoid problems getting your system approved by the owner and keep surprises once installed to a minimum. Burning the midnight oil should happen up front, before all the crews are standing around waiting for problems with containment to be fixed.

ABOUT THE THE BLOGGER Robert Ikenberry Robert Ikenberry, PCS, has been in industrial painting and construction since 1975. Now semi-retired as the Safety Director and Project Manager for California Engineering Contractors, Robert stays busy rehabbing, retrofitting and painting bridges. His documentary on the 1927 Carquinez Bridge was the pilot for National Geographic’s Break it Down and an episode of MegaStructures. SEE ALL CONTENT FROM THIS CONTRIBUTOR