Problem Solving Forum
May 31 - June 4, 2021
Under what types of exterior atmospheric exposures (other than marine) is it necessary to test for soluble salts?
Selected Answers
From
Regis Doucette of Durable Solutions on
June 4, 2021:
Testing for soluble salts on ALL external assets i ...read more
Testing for soluble salts on ALL external assets is as essential as looking at hands before eating food because if you don't assess those contaminants, you are risking unwanted grief for the asset owner. Testing for and remediating non-visible contaminants of chloride, sulfate, and nitrate ions (as the most common soluble salts) helps prevent costly call-backs, corrosion, and/or protective coating system failures. Consider that every structure that carries fuel powered equipment/vehicles is having sulfates directly deposited on it from fossil fuels combusted on those structures. Manufacturing/utility plants that have emissions, natural conditions such as volcano/fertilizers/runoffs, or highways can also be impacting structures miles away via weather patterns. Storms carry contaminants for deposition on structures miles away from those areas. Consider that major structure projects that don't address soluble salts have primer coat and top coat with visible corrosion before the bridge is even finished (e.g. Warhol Bridge in Pittsburgh). But perhaps the most important motivator for those of us in the protective coatings arena is that structure critical connections must be addressed and then chemical treatment can protect those assets so that they perform as designed. I understand the industry norm where everyone performs a "Pontius Pilate" washing of their own hands by deferring to the coating manufacturer's specifications whether to address soluble salts. However, there is written documentation provided to owners that if they want a warranty, the soluble salts threshold must be non-detectable, which is not shown on the generic public instructions. So double-speak concerns me. Again, why would anyone encourage others to not look at hands before eating food? All surfaces are at risk and must be evaluated properly.
From
S.SANKARA NARAYANAN. of SWATANTRAYA CONSULTANTANCY. on
June 4, 2021:
Salt spray test is considered to be most critical ...read more
Salt spray test is considered to be most critical as a measurement for ACCELERATED WEATHERING TEST catageroy for any given HEAVY DUTY PROTECTIVE COATING SYSTEMS TO ASSESS THE PERFORMANCE PROPERTIES. Though the results in terms of HOURS is equated to number of years with that of NATURAL WEATHERING PHENOMENA.
thank you so much ??
From
Lydia Frenzel of Advisory Council on
June 3, 2021:
Check the exterior in regional areas where there a ...read more
Check the exterior in regional areas where there are coal burning power plants, major chemical industries, pulp and paper mills.
The obvious place is where bird droppings have fallen. The national atmospheric deposition program, nadp.slh.wisc.edu will show the regions of air borne pollution that contribute to the chloride, ammonia, nitrates, sulfates, etc.
From
Tom Swan of M-TEST on
June 3, 2021:
Salts on exterior surfaces are generally not an is ...read more
Salts on exterior surfaces are generally not an issue unless there are areas where water may pool. Exceptions are areas that may be subjected to continual wetting such as surfaces around cooling towers or where continual misting of the surfaces may occur. If testing for salts, it is important to understand that ALL salts, not just chloride, sulfate, and nitrates contribute equally towards blistering so total salts should be tested for if you believe there my be a issue with soluble salts. These is a difference between soluble salts and CSN. just because there is not CSN does not mean there are no soluble salts, especially in an industrial environment. As with almost all answers, it should be added to always follow the coating manufactures directions when dealing with "Soluble Salts".
From
Michael Halliwell of Thurber Engineering Ltd. on
June 3, 2021:
Of course, if you're doing bridge work where the c ...read more
Of course, if you're doing bridge work where the climate is colder and roads are salted in the winter, you'll want to test the splash zone.
From
HECTOR MEDINA of PEQUIVEN on
June 2, 2021:
Chlor-alkaly plants, ammonia plants, and other pet ...read more
Chlor-alkaly plants, ammonia plants, and other petrochemical process units
From
Steve Brunner of Indepenent on
June 1, 2021:
The most come tested salt are the chlorides. Over ...read more
The most come tested salt are the chlorides. Over looked are the sulfates, and nitrates. These can be present in heavy industrial settings.