Ask the Expert Question-and-Answer Archive

by Ron Joseph

October, 2006

Grounding of Spray Booth Equipment

Q: I am with the US Coast Guard and am looking for advice and guidance. I am being task with grounding paint bay/booth equipment sprayers etc. In looking at  29 CFR  1915.35, I am under the impression I need to bond the metal parts of the air supplying air to the hand held sprayer, spray gun, and in this case vessel or buoy being painted. I was told the best way to do this is by installing a ground rod approximately 4' long.

My questions are is this the best way? I can't locate the directive that gives the actual requirements, the best I located was 1915.35(a)(4) that wanted all items bonded to the boat. If all metallic items in the bay are bonded together as per the NEC wouldn't a jumper to the metal parts of the air hose and a jumper to the hull of the boat work, bonding all together making all metal parts in the bay have the same potential?

Please provide any guidance you can to include size of bonding/grounding jumper OSHA standards would require and how it was sized.

A: I am not an electrical engineer or electrician. Basically, anything in the spray booth that has the potential to build up static electricity must be grounded. NFPA 33 is explicit about what needs to be grounded in a painting operation and it also gives the specification for the maximum electrical resistance that is permitted. You can download NFPA from www.nfpa.org but you will need to pay approximately $30 for the pdf. I believe that your questions will be answered by this document, but I urge you to consult with an electrical engineer or a certified electrician who understands this topic better than me.

Best wishes,

Ron Joseph