Coating Briefing
Proactive vs. Reactive Measures
-By Ian MacMoy
This article discusses why both proactive and reactive measures in coating and platings must be considered.
Proactive measures are designed solutions that are authored by the mechanical and material selection engineers of the original equipment manufacturer (OEM). The OEM expects the plating and coating to protect the part from corrosion and wear in the environment for the lifetime of the part. You would think that being proactive is the best solution and you would be right; but there are some issues that cannot be accounted for in the environment and once you have installed the equipment, it is too late. When you are engineering a solution for coating, plating, or any surface solution you must consider the substrate, the coating solution, and how they will react to each other and how they react to the environment.
Example: It has just recently come out that many of the di-electric epoxies we use subsea, and the impressed currents being used for cathodic protection, are excessive. The impressed current of negative 1.100mV is far higher than what is needed when an epoxies system of over 8 mils is applied to pipes and metal substrates. The over impressed current is only absorbed by the exposed metal, such as fastener heads and some welds. The over exposure to amps can cause hydrogen stress cracking.
Reactive Measures, are the solutions used in the field to treat products in place. Most often, reactive solutions are those correcting a prior solution or no initial solution. Maintenance is the act of renewing a part to 100% or as close to that as possible. Reactive measures would fall in this category and vice-versa. Most of the reactive solutions fall under what is permitted due to the current environment and what will last the longest until maintenance needs to be performed again, typically every six months for coatings and platings.
Many coatings and platings on the market do not provide easy or economic rehabilitation if it fails or needs maintenance. Every coating or plating proactive solution should have a maintenance product to support it in the field. When choosing a coating or plating solution, consider not just the expected lifecycle but also the reactive solutions available to reduce downtime and repair costs.
-By Ian MacMoy
This article discusses why both proactive and reactive measures in coating and platings must be considered.
Proactive measures are designed solutions that are authored by the mechanical and material selection engineers of the original equipment manufacturer (OEM). The OEM expects the plating and coating to protect the part from corrosion and wear in the environment for the lifetime of the part. You would think that being proactive is the best solution and you would be right; but there are some issues that cannot be accounted for in the environment and once you have installed the equipment, it is too late. When you are engineering a solution for coating, plating, or any surface solution you must consider the substrate, the coating solution, and how they will react to each other and how they react to the environment.
Example: It has just recently come out that many of the di-electric epoxies we use subsea, and the impressed currents being used for cathodic protection, are excessive. The impressed current of negative 1.100mV is far higher than what is needed when an epoxies system of over 8 mils is applied to pipes and metal substrates. The over impressed current is only absorbed by the exposed metal, such as fastener heads and some welds. The over exposure to amps can cause hydrogen stress cracking.
Reactive Measures, are the solutions used in the field to treat products in place. Most often, reactive solutions are those correcting a prior solution or no initial solution. Maintenance is the act of renewing a part to 100% or as close to that as possible. Reactive measures would fall in this category and vice-versa. Most of the reactive solutions fall under what is permitted due to the current environment and what will last the longest until maintenance needs to be performed again, typically every six months for coatings and platings.
Many coatings and platings on the market do not provide easy or economic rehabilitation if it fails or needs maintenance. Every coating or plating proactive solution should have a maintenance product to support it in the field. When choosing a coating or plating solution, consider not just the expected lifecycle but also the reactive solutions available to reduce downtime and repair costs.
API 20P (coating and Plating) a committee has been formed and actually been in production now for over 6 years but has slowed in recent years and never been finalized.
By the end of 2021 new committee leaders hope to put the new standard up for vote in committee and have the first edition printed by Q1 2022. Roadblocks include many of the standards which have already included coating, plating, and air-dry paint systems into their standards. API 6A and API 20E among others have covered these areas prior, due to the irrevocable damage they cause when internal processes are not standardized and processes regulated. Why is the API standardizing (plating and coatings)? Remember, that it was the API that was charged with the task of cracking down on hydrogen embrittlement in bolting and it has been only recently that internal processes have been banned, (zinc plating). After multiple testing in SC 221 and other API member studies, it has been made obvious that these processes require a standardized form and direction. One that the other API standards can adopt and reference in their own standards.
By the end of 2021 new committee leaders hope to put the new standard up for vote in committee and have the first edition printed by Q1 2022. Roadblocks include many of the standards which have already included coating, plating, and air-dry paint systems into their standards. API 6A and API 20E among others have covered these areas prior, due to the irrevocable damage they cause when internal processes are not standardized and processes regulated. Why is the API standardizing (plating and coatings)? Remember, that it was the API that was charged with the task of cracking down on hydrogen embrittlement in bolting and it has been only recently that internal processes have been banned, (zinc plating). After multiple testing in SC 221 and other API member studies, it has been made obvious that these processes require a standardized form and direction. One that the other API standards can adopt and reference in their own standards.
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