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Electrolysis metal pipe

2006

We have several metal light poles in a trailer park, the electrolysis is slowly eating them I measured a 3/10 to 4/10 dc volts from the pole to ground.
Years ago I went to a school at the department of defense on this subject, cannot find my manuals on this.
Any suggestions or information on this problem will be appreciated.

Leroy F [last name deleted for privacy by Editor]

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2006

Some general suggestions which may be modified depending upon materials of construction:
First, verify no stray electrical current -- any change in voltage with power off or on?
Remove bulk of corrosion by stainless steel wire brushing or high pressure water. Finish cleaning and pretreat using a phosphoric acid-based gel ("rust remover"). Rinse & allow to dry. Apply a Cold Galvanizing Compound / Zinc Rich Paint and either a polyurethane topcoat or an aluminum-fibered asphaltic paint ("roofing tar").

For galvanic corrosion, see MIL-STD-889 (with Notices) "DISSIMILAR METALS."
For surface preparation, coating selection and application, etc., see MIL-HDBK-1110 "HANDBOOK FOR PAINTS AND PROTECTIVE COATINGS FOR FACILITIES."

Ken Vlach [deceased]
- Goleta, California
Finishing.com honored Ken for his countless carefully researched responses. He passed away May 14, 2015.
Rest in peace, Ken. Thank you for your hard work which the finishing world, and we at finishing.com, continue to benefit from.