In the corrosion world it is generally accepted that there are eight basic types of corrosion. From this simple list of corrosion types, a daunting variety of corrosion related problems are encountered every day by people from all walks of life. On the corrosion solution side, there are only a handful of fundamental corrosion remedies, but there is an equally daunting number of products and processes available to solve corrosion problems.
Given the sheer variety of corrosion conditions and solutions, it is all too easy for the proprietor or asset owner to make incorrect assumptions, jump to a premature conclusion and pick the wrong solution for a given corrosion problem. (Or possibly even a solution that has hazards, as discussed in The Dangers of Typical Corrosion Prevention Solutions.)
The odds are that a corrosion expert has encountered the same problem and found one or more solutions. For the asset owner or proprietor, a process plan is needed to find corrosion solutions for those small-to-medium sized corrosion problems. Matching a particular corrosion problem with a correct solution is, of course, the objective. But going a step further and finding the best solution is the real goal. A problem-solving process plan is always recommended for project success.
This article will walk you through a process of twelve steps to help find the best solution.
1. Gather Documentation About Corrosion and the Environment
Begin by gathering and documenting all available information with respect to the corrosion situation and the local environment.
Take multiple pictures and include close-ups as well as wide-angle shots. If possible, obtain a sample of corroded part(s). With direct visual observation of the corrosion, attempt to determine the type of material or materials involved. This may be fairly simple if the material or product is labeled, but may be difficult or nearly impossible without laboratory testing.
- Type of materials undergoing corrosion and adjacent uncorroded materials also
- Types of exposure to weather, humidity, temperature variations, fresh water or salt water, or chemicals that act as electrolytes
- Whether there has been contact between the corroded object(s) and other materials or surfaces (as is sometimes the case with dissimilar metal corrosion)
- The length of time that corrosion has been in progress and how widespread the problem is
- Whether the corrosion is a chronic issue or one brought on by a specific event or environmental situation
- If one or more of the eight corrosion types can be identified
- If there have been any prior attempts to mitigate corrosion (for example - painting, coating, sealing)
There will almost certainly be information gaps in what you find. Regardless, gather as much data as reasonably possible.
2. Begin Preliminary Research
With the information gathered, begin preliminary research. A simple internet search using keywords from the information gathering stage will likely come up with multiple ideas to pursue. Also, consider making a contact with an expert in a trade organization or industry if the problem appears to have industrial characteristics. Ask for information or case studies of similar situations. (For an example of a case study, see Case Study: Remediation of 1960s-Era Concrete Silos.)
3. Conduct Research
With the first-hand information and preliminary research in steps 1 and 2 above, you may know what kind of corrosion you are dealing with and the solutions may be straightforward. If you are confident, skip ahead to Step 5.
On the other hand, if there is uncertainty, further research is needed. Another internet search may be helpful. Corrosion testing and a laboratory analysis may be justified and a local university may have students available to perform one for free or a small fee. (Learn more in Corrosion Assessment: 8 Corrosion Tests That Help Engineers Mitigate Corrosion.) Engineering or metallurgical labs may be found in most metropolitan areas.
Now that you have done a bit of research you know what to look for. Take another look at the corrosion affected area. Information that was overlooked the first time may be obvious now. Using all available data, information, case studies and advice, formulate a fundamental understanding of the corrosion problem and prepare a detailed written description of the problem. Double-check your description for clarity.
4. Contact Corrosion or Coating Solution Experts
With the written description of the corrosion problem from Step 3 above, engage (if you have not already done so) or re-engage multiple individuals in appropriate trade organizations, online sources and companies. Share the written description and ask for any ideas they may have. Also, it is now time to initiate conversations with multiple corrosion product and process vendors and providers. Engaging a corrosion consultant may be warranted if the problem is chronic, costly or simply too difficult to get a good grasp of.
5. Prepare a Request for Quotation (RFQ)
Using information from all the previous steps, prepare a detailed, written request for quote (RFQ) that outlines the corrosion problem and asks for solution options with the applicable parameters listed and described below. (For more ideas, see Strategy for a Corrosion Remediation Program.) Be certain to describe the ultimate desired outcome. Examples questions to ask yourself:
- Is the removal of all existing corrosion as well as stopping future corrosion demanded, or is simply stopping new corrosion the goal?
- Can the corroded asset be removed from service, and if so, for how long?
- Is final appearance important?
- Case studies for similar situations
- Material safety data sheets (MSDS)
- Amount, cost, availability and delivery
- Ease or difficulty of application
- Effectiveness, longevity
- Safety and environmental hazards
- Authorized contractors
- Training for product appliers
- Surface preparation procedures/recommendations
- Application procedures
- Length of time asset can be removed from service
- Curing process and timing
- Follow-up maintenance
- Sample availability
Submit this RFQ to appropriate corrosion vendors and/or service providers. Request options with vendor proposals and state a deadline for submission.
6. Obtain the Proposals from Vendors
Before preparing a summary spreadsheet, read each proposal carefully. Determine if the vendor has understood both the specific corrosion problem and desired end state. Do not be surprised if there are a variety of solutions offered. A rank ordering of the proposals (from best to worst) based on your perception of the vendor’s understanding of the problem and potential solutions is recommended. Finally, prepare a comparative spreadsheet of the proposals.
7. Narrow the List of Proposals
Upon completion of the spreadsheet, a best solution may be self-evident. More likely, however, there will be several solutions that are appealing. Be sure to consider newer technologies as well as tried-and-true solutions. Narrow the product/process considerations to the best two or three.
8. Perform a Quick Test of the Proposed Solution
If the project is large, mistakes costly, and time permits, perform a trial on a small sample area or test surface. Since corrosion often has a long time horizon, customers often are forced to rely on the vendor’s prior testing.
9. Re-engage with Vendors or Contractors on the Short List
Re-engage with the final two or three vendors and any contractors that may become involved with the application or installation of products. Ask a lot of questions. Good vendors and contractors will provide both pros and cons for their products and service offerings. Confirm quantities, pricing and delivery. Add these last-minute findings to the summary spreadsheet.
10. Place the Order
Make a final selection and place the order with the successful product/process vendor. Upon delivery of products, confirm that the correct product was received, that it was not damaged or exposed to out of specification temperatures in transit, and that the product is still within shelf life parameters.
11. Prepare for the Work Effort
Meet and discuss with successful contractor(s) before application or installation to insure the work is done correctly and follows all procedures. Upon completion of the project the contractor should provide a detailed summary of the work performed along with the invoice. A qualified coating inspector or other corrosion professional will be of great value if the project or process has multiple steps or other complications.
12. Evaluate the Results
Establish follow-up procedures such as an inspection and test plan to evaluate long-term results.
By following these twelve steps, the proprietor can feel confident that they are going to find not only an excellent corrosion solution, but hopefully the best one for the problem at hand.