Field Methods for Extraction and Analysis of Soluble Salts

By Heather Stiner | Published: December 13, 2016

Lou: Welcome again! Good morning, good afternoon, or good evening to everyone who has joined us worldwide for what we believe will be an excellent presentation on soluble salts and how they impact protective coatings. I’m Lou Frank, publisher of the Corrosionpedia, the world’s largest web-based platform designed to help Corrosion Professionals.

Corrosionpedia is honored to host today's presentation featuring Heather Stiner from SSPC. Heather is a chemist who has developed an expertise in the field of protective coatings. She'll help us today as she explores various procedures for extracting and analyzing soluble salts on steel prior to applying protective coatings. Heather is well qualified to speak on this topic. She’s been working in the field for nearly two decades. Along with a chemistry degree from the University of Pittsburgh, she has earned a couple of widely recognized certifications including SSPC’s Protective Coatings Specialist and Concrete Coatings Inspector.

Heather, it's a pleasure to welcome you today.

Heather: Thanks, Lou! I’m happy to be here, and I’m really looking forward to showing some good info on this giant issue of salts, including to our viewers today. Thank you so much for making this opportunity possible for me.

Lou: You bet, Heather. We’re excited to have you. We’re really pleased to have a dynamic audience today. Looking over the list of attendees, we've got professionals from throughout the industry and literally from all over the world joining us. I'm sure some of you in the audience have come with questions already in the end. Others of you I’m sure will have questions that arise during the presentation. At any time, please use that dialog box on the right side of your screen to post those questions; we encourage them. And I promise, we'll get to them immediately at the end of the presentation.

Heather, you’ve been around the coatings industry for a while now. I know you got started with one of the industry’s giants, PPG, and then worked your way into a key role here at SSPC. How about telling our audience briefly about your mission?

Heather: Sure. I’ve been with SSPC for about 11 years now, and I’m the Manager of Technical Services. I’ve really enjoyed my role here as an SSPC staff member and technical expert. I’ve worked as both an instructor as well as a contributing author for several SSPC training courses. It’s been really satisfying to me to be able to be engaged and to help see improvements in those people's careers and the industry in general so that we get to see the performance of coatings get better and better.

Lou: Hey, that’s neat. During our preparation for today’s webinar, you told me a story about your first experience with soluble salts and coating, and you needed a little bit of help. While we’re waiting for the rest of our audience to join us, how about quickly relating that story to everyone?

Heather: Sure. So, my first experience with adverse effects of soluble salts on coatings happened back in 1999. I just started my career as an organic formulation chemist, and I was sent out to the field to provide some technical support to one of our largest customers with who I was working for. The moment that I arrived at the job site, I couldn't help but notice that the coating, it had blisters all over it. We did a failure investigation, and it was discovered that the failure was caused by osmotic blistering, where soluble salts and the moisture is actually get trapped between the substrate and the coating. That coating then had to be completely removed and reapplied and that cost the owner of the project several millions of dollars and a lot of downtime that wasn't expected in the project. The memory of what I saw that day and the many such stories that I've heard since has really helped me and inspired me to speak today on this really important and relevant topic.

Lou: Wow, what an experience. A lot of folks, perhaps even in our audience, have had that experience. I've certainly seen some of those failures. I know a lot of other folks have.

Well, I think—thank you for that, Heather. I think we've long enough to allow for any late arrivals. Let’s move on with the presentation. We're here today to talk, not so much about you Heather, but really more about how to help people understand, or maybe even prevent, coatings issues related to surfaces that are contaminated with soluble salts.

One thing before we get started, today's presentation is sponsored by SSPC, the Society for Protective Coatings. SSPC was established in 1950 to advance the technology and promote the use of protective coatings to preserve industrial, marine and commercial structures, components, and substrates. Today, the organization has over 11,000 individual members and nearly 1,000 organizational members. Based in Pittsburgh, Pennsylvania, SSPC has local chapters throughout the world that enable members to interact with other protective coating industry experts close to home. SSPC is in fact the leading source of information on surface preparation, coating selection, coating application, environmental regulations, and health and safety issues that affect the protective coatings industry. We are really happy to have SSPC as a sponsor today.

Oh, and one last reminder for all of us in the. About questions, feel free to post those questions throughout the presentation using that dialog box on the right side of your screen. I promise we'll get to them right at the end of Heather's presentation.

Heather, it's all yours.

Heather: Alright, great!

Hello everyone. Thank you again for taking the time out of your busy schedule to listen to me chat about methods for testing and extracting of soluble salts. As I already explained, I am the Manager of Technical Services at SSPC. SSPC does develop consensus based industry standards, and we currently have about 101 published. One of the standards is SSPC Guide 15. This guide focuses on different test methods for testing for soluble salts and conductivity and explains the advantages and disadvantages of each of those test methods. Today, this webinar is going to summarize this guide. Again, as Lou stated, when questions arise, please don’t hesitate to ask. I'll try to answer them to the best of my knowledge. If there's a question I don't know, I will get the answer for you. I’ll reach out to our SSPC committee and seek the answer for you and get back to you as soon as possible.

It's imperative for me to mention in this introduction that coatings applied on surfaces contaminated with soluble salts do run the risk of a diminished performance. Likewise, if you have a metal that is and is not intended to be coated, that can also compromise if elevated concentrations of residual soluble salts are in a corrosive environment.

Soluble salts testing does involve two major steps: one is the extraction of salt from the surface into a solution, and then the second major step is the analysis of the solution itself. This webinar is going to intend to assist the user in selecting specific procedures for extracting and performing qualitative as well as quantitative soluble salts from steel and non-porous surfaces. It's going to include field methods for measuring total conductivity, and we’ll also talk about measuring specific ion as well.

So, a lot of you are attending this presentation might say why are we making all this fuss over soluble salts and why test for soluble salts. First, what are soluble salts? in simple terms, it’s a salt that when in contact with a liquid, dissolves. For our conversation today, we’ll be talking about salts that are dissolving in water and moisture on a surface or substrate. Then the second question is, why test for soluble salts, why is it so important? Because if left on a surface, salts can be detrimental to the coating and cause degradation such as poor adhesion of the coating, as well as you heard me talk a little bit ago in my intro about osmotic blistering. Osmotic blistering is a situation where blisters are formed due to water diffusion through the film, and it dilutes the underlying solute by a process that we term as osmosis.

In my earlier slides, I talked that this webinar is going to focus a lot on SSPC Guide 15. I do want to note that Guide 15, the most current active version out there, is from July 2013. Within this guide is a very useful table for selecting a method for measuring soluble salts. It’s titled “Overview of Field Methods for Retrieval and Analysis of Soluble Salts from Steel and Other Non-Porous Surfaces”. I want to point this out because the table holds a lot of important information, and the table is actually too large for me to be able to include in this presentation. So, the table does point out the methodology for conducting measurements. It talks about the reference standards to be used when performing that measurement, and we’re talking about standards from SSPC, ISO and NACE. And then it talks about the analysis process for extracting the soluble salts and the process for calculating the surface concentration of ions.

So, moving into the different methods for measuring salt, we're going to talk about two main different methods: one is the Fully Automated Conductivity Measurement, and then the second is going to be the Multi-Step Conductivity Measurement. I'm not going to go into the sub bullets on this slide because the slides that are to follow will cover each of these methods in detail.

When we're talking about Fully Automated Conductivity Measurement, recent innovations and salinity testing devices have resulted in a direct, real-time automated, integrated systems that do a composite standard ISO 8502-9, which is the standard that covers field methods for conductometric determination of water soluble salts. These devices are alternatives to patch cells and measures solution salinity from conductance which will be discussed later in more detail. I do want to point out that all of these devices attached to metal surfaces either magnetically or with a nonresidue tape. The fixed volume of pure extraction water is automatically dispensed and agitated against the metal surface to extract the soluble salts, and then conductance measurements are taken in real time. The devices, process conductance data to generate surface concentration, and then they do store the data and results internally.

This photo here is showing you an example of one of the different versions of automated salt meters that are out there today. If you notice, this gauge uses high-purity water, and they take filter paper that is placed onto a clean non-labeled side of a magnetic disk. The water from the syringe is dispersed evenly across the filter paper, and then it's important to remove any of the bubbles from under the paper. They placed a magnetic disc with wetted paper face down on the area under the test. They press firmly into the contours or irregularities, and then they start a 2-minute timer on the gauge to take the reading. After those two minutes, they carefully remove the filter paper and the magnetic disc from the test surface, and place it on to measurement electrodes. They close the lid, ensuring that the magnetic catch is fully engaged, and then they can automatically get a reading.

This slide here is another version of another type of automated salt meter. The soluble salt tester here measures the concentration of soluble salts on a metal surface in accordance with two ISO standards: ISO 8502-6, which is the extraction of soluble contamination for analysis by the Bresle method, as well as ISO 8502-9, which is the field method for the conductometric determination of water soluble salt.

Another version of an automated salt meter is the one in this photo. This soluble salt meter is a handheld device that is fully automated to perform salt sample extraction and analysis. The device does come with a self-contained fluid dispenser that does deliver accurate, pre-measured volumes of re-agent water for soluble salt measurements and post measurement flushing. The device does include interchangeable silicone rubber line magnetic heads of different curvatures and provides an onscreen instruction for use. The meter does include an interface for connection to external peripheral equipment, and it measures conductance.

This gauge here is called the Continuous Flow Extraction Fiber Strip. This method requires use of a pre-measured solvent ampule that is actually attached to a disposable sensor and a reusable meter to analyze the extracted solution. Surface soluble salts are extracted by the flow of solvent across an engineered fiber in the sensor. Then that extracted salt solution is collected in the sensor’s reservoir. It uses a pair of electrodes that extend out of the bodies of the sensors. When these electrodes are placed in the accompanying meter, you get a direct reading of electrical conductivity proportional to concentration of the soluble salt ion and is displayed on the meter. The measurement process does not require any manual manipulation. The contact area of the unit is approximately 1.5 cm x 2 cm and does not fill to the test surface. The method permits evaluation of curved, regular and highly constrained test areas.

So, here are some advantages whenever you're using an automated method:

  • The sensors will attach magnetically to some metals.
  • The methods are real time and they do display on the meter guide for the user through the complete procedure.
  • All the critical steps are automated and pre-measured; therefore, you have less subject to operator error.
  • Reduced setup, so extraction from the surface and data reduction time.
  • The testing can be performed on vertical, horizontal, as well as overhead surfaces.
  • They give you a digital output and electronic reading capability.
  • You have a reduction in consumables, and typically no hazardous materials are required.
  • The readings may be recorded, and
  • The sensor test area is standardized and cannot be manipulated by the user.

Some limitations whenever you're using the gauges:

  • Some of the meters may not conform to curved and irregular surfaces.
  • Some of the sensors will not adhere to a surface that is not magnetic.
  • The instrument measures conductivity of total soluble salts rather than a specific ion, such as chloride and nitrates.
  • Fully automated conductivity measurement techniques must be purchased as systems and are not interchangeable.
  • The swabbing retrieval method provides a means for acquiring samples of salt from steel or other nonporous surfaces using readily available materials.
  • The extractions can be conducted on a range of surfaces without regard of surface irregularities or conditions.
  • The swabbing method can be used on large areas to indicate general surface contamination by salts.
  • The extractions also provide sufficient sample size for several analyses to be performed for different ions.

Manufacturers may provide curved head to accommodate for this situation.

The units can be held in place manually.

We'll talk about specific ion testing further down in the webinar.

So, now we're going to talk about Surface Swab or Wash/Probe Type Conductivity Meter Techniques. This is an image of such an instrument. It is a low conductivity fluid such as reagent water is used to extract the salts from a steel or nonporous surface. The method does require that the operator wear chloride-free latex gloves to prevent cross contamination of the touched surface. The method does require a ruler or a template, markers, clean beakers, tweezers and reagent water. The method is pretty simple to perform, but it is labor intensive, and it follows only ISO 8502-2 which is the laboratory determination of chloride on clean surfaces.

Advantages of this test:

Some limitations to using this technique:

  • The swabbing methods are difficult to perform when you're doing overhead or vertical position.
  • Swabbing is not well suited for measuring salt levels of small localized contamination such as craters or pits.
  • There is a risk of contamination of a sample by the operator if gloves or any other equipment used for these procedures become damaged.
  • And in hot weather or on hot surfaces, the extraction liquid may evaporate on the surface prior to removal.

Extracted liquid may be lost during the dripping of the swabs when you're using the overhead or vertical position.

Now I want to talk about the Bresle Cell Patch Kit. This method utilizes a small adhesive patch, and it’s covered with a latex film which attaches to the surface, forming a cell cavity. Self-contained adhesive edges allow the cell to adhere to a surface. The reagent water or a proprietary extraction liquid is then injected into a center with a hypodermic needle. The patch is filled up like a large pink blister. Using the hypodermic needle, the liquid is then sucked out of the compartment and reinjected a minimum of four times before being retrieved from the patch using the hypodermic needle, and test it for concentration of ions as probe type conductivity meter. The patch cell sampling procedure is described in detail in ISO 8502-6, which is the extraction of soluble contaminants analysis by the Bresle method. Standardization for practices for soluble salt retrieval patch cells and equivalent in conductometric measurements is also given in NACE SP0508-2010. You can also look at additional specifications that are available on manufacturer and distributor websites as well.

This slide here is showing you the steps that I just discussed on the previous slide of how to actually do a test. You start here where you fill up your syringe with the liquid. You inject the liquid into the cell. You massage the cell patch, and eject and inject the liquid approximately four times. You then take the liquid from the last extraction from the cell patch, and you're going to go ahead and use this conductivity meter or a similar one from a different manufacturer to test your concentration.

Advantages of the Bresle cell patch method:

  • The cells as attached with adhesive can conform to curved and irregular surfaces.
  • The cells such as these are commercially available in a variety of sizes.
  • If reagent water has been used as the extraction liquid, conductivity can be determined using commercially-available conductivity meters as well.
  • The patch cells only accommodate a small amount of extraction liquid.
  • No in series determination of conductivity can be performed with these cells.
  • The cell may not adhere well to heavily rusted surfaces, but it may adhere to abrasive blast cleaned surfaces that it’s actually difficult to remove the patch itself.
  • The cell can leak through the hole introduced by the syringe.
  • The cells are consumable and can only be used once.
  • The patch cell will add background conductivity at times.

The most commonly used size retrieves salts from a surface of 12.5 cm2. Smaller cell size permit extraction of surface cells to be made at local corrosion sites. I do want to comment that if you do pull a cell that’s a different size than 12.5 cm2, you have to adjust that in your calculation for area.

Some limitations for this method:

When the most commonly used cell size, the actual quantity of the cell liquid contacting the surface is about 3 mm, this can limit the range of analysis that can be performed.

Additional limitations:

Further limitations:

  • Dilution of the extraction liquid introduces greater error in the final result.
  • No standard practice or procedure exists for the intensity of rubbing; thus, this makes the result subject to operator use.
  • Some flexible patches can be stressed to 10% more than their original intended footprint, and this can influence the final result as well.
  • And when acidic extraction solutions are used, the patch cell is not suitable for conductivity measurements.

I believe at this time, we’re going to take a break.

Lou: Heather, thank you for powering through the first half. Good chance for you to sit back and drink a glass of water or what have you. Your presentation is excellent. We already have a few questions that we’ll address as your presentation ends—some good ones. Actually, another one just popped in. Kind of fun.

For all of you in the audience, please keep those questions coming. Also, each of you in the audience will have access to this recorded presentation. Corrosionpedia will email you a link to that in the next few days. And as a reminder, today's presentation is sponsored by SSPC, the Society for Protective Coatings. SSPC is the leading source of information on surface preparation, coating selection, and other key issues that affect the protective coatings industry, helping preserve industrial, marine, and commercial structures globally.

Alright, Heather, hopefully you've had a glass of water. I had a chance to do that while you were talking, so I think you’re back up on the phone. Are you ready?

Heather: Yep, I sure am.

Lou: Alright, let’s get into the heart of the presentation.

Heather: Okay. So, the next method we’re going to talk about for measuring soluble salts is the Saturated Special Filter Paper/Concentric Ring Conductivity Meter Technique. This method incorporates soluble salt extraction with water saturated filter paper and analysis using conductivity. The paper wets the surface and extracts soluble salts through absorbance. After a predetermined time, the paper is removed from the surface and placed over the electrodes of a proprietary concentric ring conductivity meter. The meter indicates the conductivity of the wetted paper.

Some advantages for this:

  • It’s suitable for a wide range of shapes, orientations, surface, and finishes.
  • It is battery operated and portable.
  • It has onboard temperature compensation.

It can provide multiple readings that can be downloaded in real-time via USB or Bluetooth and can be stored in multiple batches with date and time stamps, temperature, and the size of the test paper. And it does have a measuring range up to 15 micrograms/cm2.

Some limitations for this method:

  • There's no in-series determination of the conductivity that can be performed using this unit.
  • The water may be lost from the filter paper introducing error.
  • The filter paper is a consumable and can only be used once to extract the salts.
  • And you get background calibrations for the blank filter paper must be manually performed.

So now we’re going to move into some Field Methods for Measuring Specific Ions. I'm not going to go through this list one by one because we're going to go ahead and go into detail in the slides that follow.

So, the first I’m going to talk about is Chloride Ion Paper Strip Test of Swab/Wash or Latex Patch/Cell Extract. In this technique, chloride ion paper test strips are utilized to determine the chloride ion concentrations of a swab or patch cell extracted solution. So, whenever you're doing this method, extraction solution is obtained using either the swab or patch cell method. The lower end of a chloride ion paper strip is placed into the extracted solution. The solution wets up and saturates the test strips, as indicated by the yellow band across the top of the strip turning blue, and that usually takes about 5 minutes. Then the scale number at the top edge of the white column is recorded. The chloride ion causes the existing tan color on the strip to turn white. And compared with the conversion chart includes with the test strip bottle. The range of concentration over which this method is useful is from 30 to about 600+ PPM of chloride ion. In the reported by the manufacturer using these test strips is ±10% chloride. When you're performing the calculations, the rating from the paper strips must be converted to PPM using the conversion chart supplied by the manufacturer, corresponding to the batch of the test strip used for that analysis.

The next method we’re going to talk about, a technique that uses sealed vacuum tubes, and they’re utilized to determine the chloride ion concentrations of swab or patch cell extracted solution. The extraction solution is attained using either the swab or patch cell method. The tubes contain crystals that are impregnated with silver dichromate. The ends of the tube are snapped off, opening the tube much like a straw. When one end of the tube is immersed in the extract solution, capillary action whips the solution to the top of the tube. On contact with the chloride ion, the silver dichromate converts to silver chloride. And then when the solution reaches to the top of the tube, the white cotton at the top changes color to amber. This indicates the titration is complete. Graduations inside of the tube provide the level of chloride ions present in a solution. This method is described in detail in the standard ISO 8502-5, which is the measurement of chloride on steel surfaces prepared for painting, and is the Ion Detection Tube method. It can detect chloride levels from 1-2000 PPM using tubes of varying ranges of detection.

The next one that we're going to talk about is the Ferrous Ion Paper Strip Test. This technique, the ferrous ion paper strips are utilized to determine the ferrous ion concentration of a swab or patch cell extracted solution. Extraction solution is obtained using either the swab or patch test cell method. To determine the ferrous ion concentration in parts per million, you moisten a ferrous ion test strip with the solution being tested, and then you’re going to compare the resulting color to the color chart on the container label.

The next test we’re going to talk about is the Field Drop Titration for Chloride. In this method, a commercially available test kit is used to analyze the solution collected from the surface using swab or patch cell extraction method. Extraction solution is obtained using either the swab or patch cell method. The titration, which sometimes here is referred to as drop titration, is performed on a small sample, typically around 2-3 ml from the extracted solution. The kit includes three solutions contain and separate reagent bottles.

So, you go through three steps here when performing this test. The first step, you’re going to use Reagent bottle 1 and squeeze or press out two drops of red indicator liquid into a plastic vial containing the sample solution. You're going to carefully agitate the liquid until it is a homogeneous in color. The second step, you're going to use Reagent bottle 2, squeeze out two drops into the vial. The sample liquid should be yellow in color. And then the third step, you add a drop—drop the contents from Reagent bottle 4. Count the number of drops required to turn the solution from yellow to blue. You'll thoroughly agitate the solution after the addition of each drop. And this procedure is described in detail in ISO 8502-10.

You are then going to use the chart to determine the concentration of chloride ion in the sample, and this goes by the number of drops that you had to use in the third step.

So, the next test we’re going to talk about is the Latex Sleeve Methodology. This method uses a small flexible chloride free latex sleeve or sock with a self-contained adhesive edge. A proprietary solution is dosed into the sleeve, and the sleeve is attached to the structure being tested, forming a cavity. The solution is massaged against the surface being tested for a specified period of time and is then removed. The sleeve then is removed and extracted solution tested for levels of chlorides.

Here in this photo, we’re showing the components of the Latex Sleeve Methodology. Testing procedure may be conducted on intact painted surfaces and/or bare metal, nonmetal surfaces. It is important to note that you should remove all rust, loose paint and dust prior to testing. The first step is you’re going to remove the cap from the sealed ampule of premeasured extract solution and pour the entire contents into the sleeve. Then you’re going to remove the pressure sensitive backing from the sleeve adhesive ring. You’ll then remove most of the air from within the sleeve by squeezing the sleeve between fingers and thumb. It’s important to not spill any extraction solution from the sleeve when evacuating the air. We then want to firmly apply the sleeve to the test surface. Lift and hold the free end of sleeve operate to allow the extraction liquid to come into contact with the surface. Use the other hand to massage the solution through the sleeve against the surface for 2 minutes. I also want to note that increasing the massage time will increase the extent of salt removal. When the massage is complete, remove the saline solution from the surface. For vertical or overhead surfaces, the extract solution will return to the lower area in the test sleeve. When you're doing this on horizontal surfaces, press and finger across the sleeve to move the solution to the closed end of the sleeve prior to removal.

Advantages of this test method:

  • It’s very simple to perform as all, as all components are premeasured for you.
  • The adhesive sleeve can conform to curved and irregular surfaces, meaning that you can do the test on vertical, horizontal, as well as overhead surfaces.
  • And for extremely rough or pitted surfaces, the seal ring may be doubled, thereby allowing testing to be performed.

Additional advantages:

  • The kit form of this method provides a premeasured volume of extraction solution and a fixed area of the sleeve opening.
  • All components are one-time usage, eliminating cross contamination from test to test.
  • And in hot weather or on hot surfaces, the encapsulated extract solution will not evaporate.
  • Additionally, the extractions also provide sufficient sample size for analyses to be performed for different ions.
  • Acidic extraction liquids normally provide improved extraction efficiency compared to the reagent water.

And then some limitations:

  • The adhesive sleeve may not adhere well to rusted surfaces, but may adhere so well to clean or grit blasted surfaces that it is difficult to remove the adhesive sleeve from the surface.
  • There is no in-line conductivity that can be performed with the sleeves.
  • And the sleeves are consumable and can only be used once.

The next test we’re going to talk about is Field Detection Sulfate Ion by Visual Turbidity. This method works on the principle that if sulfate is present in the extracted salt solution, it becomes turbid or cloudy when barium chloride is added. The simplest instrument for measuring the degree of turbidity in the field is the optical comparator. Barium chloride is available as a powder or pre-measured tablet. The tablets are more convenient to use that require time to dissolve. known degree of cloudiness are compared side-by-side with the sample prepared using a kit. The closest in cloudiness to that of the sample is taken as a sample sulfate level. The interval between each value has to be quite large, because the eye is not as discriminating as well calibrated spectrophotometer is in the laboratory. Also, because the eye is not sensitive, the very low levels of turbidity, the minimum level of sulfate that can be detected by this method is around 20 PPM.

And then next I want to talk about Qualitative Field Detection of Ferrous Ions. In this method—and this is prescribed in ISO 8502-12, which is the field method for the titrometric determination of water soluble ferrous ions—you're going to use blotting paper, and it is treated with potassium ferricyanide solution. The blotting paper is moistened and placed in contact with a steel surface to be tested. On contact with ferrous ions, the paper will show blue spots. The sensitivity of the method is less than 1 PPM ferrous ion. This is a qualitative test, but one manufacturer of the test provides a comparison chart against which the test papers are visually compared to give an indication of the extent of metallic salt contamination. Any contamination is indicated, a quantitative test is recommended. Potassium ferrocyanide test paper may be used as an economic screening test for active corrosion sites. It is specific to soluble ferrous ions. When used properly, it will not give false negatives, but may produce false positives. When soluble salt concentration is suspected due to a positive indication using potassium ferrocyanide paper, then confirming tests utilizing a quantitative method may be required.

So, I covered a lot today in this webinar and went over many different tests, and I know it was a lot of information to provide at one time, so I want to give you a slide here that tells you where you can get additional resources. SSPC Volume 1 has actually recently been completely overhauled and updated. It has an article in there that covers soluble salts in more detail about what soluble salts do to the surface when it’s not removed prior to coating. And then we also have SSPC Guide 15 which can be found in SSPC Volume 2. And then we also have a new standard in development that is going to talk about when, where, and how many salt readings should be taken. You can find all of the ISO references that I talked about in this presentation from the ISO website, which is www.iso.org. And then I also want to point out that NACE has a few publications as well that you can use for when you're doing testing of soluble salts, and can be attained at their website at www.nace.org. One of those is a new standard that recently came out on the market, or recently been published, and it's NACE SPO716 which is soluble salt testing frequency and locations on previously coated surfaces.

So, in summary, I hope everybody enjoyed the webinar. I described several ways to test for soluble salts on a surface and about different techniques to be used, and whether or not you should be using that technique for the specific situation that is at hand. And at that, I would like to open it up for questions. And on here is my contact information as well if anybody would like to contact me post webinar.

Lou: Heather, thank you. Oh my gosh! What an informative, in-depth presentation. You covered a surprising array of issues for our audience to consider. Thank you to the interested men and women in our audience for joining us today. Each of you will have access to this recorded presentation. Corrosionpedia will email you a link to that in the next few days. And thank you to our sponsor SSPC. The organization that helps the best use of protective coatings to preserve structures globally.

Heather, you’re right. We have an amazing today, and there are a lot of questions. It's kind of fun. I’ve actually been scanning through them as you were talking. I’m kind of going to go back to one of the early questions. Carl Murray is asking two different things. So, I’m going to throw both of them actually because they’re short. “Are the automated methods equivalent to the paper test method, and can we do the salt test on garnet with the Bresle method?”

Heather: Sorry, I’m writing this down. So, to do the salt test with the garnet, I’m going to deal with that question first. There is a test called the Vial Test where you take your garnet and you put it into clean water and you shake your garnet for a period of time, or your abrasive that is in that solution, for X period of time. And then you can extract the solution that comes off of that from shaking the vial. You extract some of the solution out and then you can use that to test using a conductivity meter or one of the other test methods that I talked about, and then you don't have to incorporate the Bresle patch method into that. And that test actually talks about in our abrasive standard, SSPC’s abrasive standard, which is AB 1 or AB 2.

Lou: Gotcha. Thank you. We’ve got some…

Heather: The automated method… I have to say there is a second question that dealt with automated—is the automated method equivalent to the paper method? And I'm going to be—I would like to answer that. I have my opinion on it, but I think it’s best that I take that question back to the committee that helped develop Guide 15 to make sure that everybody is in agreement of how that should be answered.

Lou: That's a great way of handling it. You’ve got a number of professionals within the SSPC community that can help you with that. I have a couple of very technical questions from Nico. My guess is the answer is going to be the same, and I'll read this to you, we’ll have them in writing between us when we're all done here, Heather, so just here. How do we deal with Bresle patches that are claimed to be in accordance with ISO 8502-6, and just a conductivity while the mandatory 8502 Annex A Test is not met and the patches will leak? Those are not according to 8502-6. What's the best way to deal with that?

Heather: So, in my opinion, if you’re required to meet ISO 8502-6, then you have to make sure you purchase the Bresle patch that says that it’s meeting that. In regard to the patches that leak, is his question stating that that they meet ISO 8502-6, that they’re leaking and really don’t need it? Is that what I’m gathering?

Lou: Yes. It is. And Nico, hopefully you're still online. If you want to clarify that with a new question, that's fine, but it appears that yes, if it doesn't need be Annex A part of the 8502-6.

Heather: Yeah, that may be something that whoever's purchasing that Bresle patch would have to go back to the manufacturer of the Bresle patch and ask them the questions of how they meet ISO 8502-6 and the Annex of it, and the user would want to explain to them how they're having the leaking issue.

Lou: Perfect. One of the questions that you and I talked about when we were getting ready for this is one that actually got posted and I’m thrilled a bit to see it here. Richard has asked, “What is the industry standard for acceptable soluble salts?”

Heather: Currently, there is no industry standard that states what is acceptable in the amount of soluble salt on a substrate; however, there are some folks out there that have what’s written into their standard operating procedures or their own standards what they feel is acceptable for what work is being performed in their facility or at their location. One of those is the US Navy. They do have requirements set on soluble salts testing written within their standard items that deals with coating their structures. So, it's important that whenever somebody is going out in the field to do this that they talk with the owner and they review the specifications and the standard operating procedures. Make sure that they understand what is acceptable and not acceptable.

Lou: Gotcha. Makes some sense. Another question. John asked, “Do all the test methods measure conductivity or are there some kits that determine ion specific contamination?”

Heather: Some only measure conductivity and some only measure ion specifics. So, it's important to know what you are to be testing for if you're out there doing these tests. I covered which ones in the slide presentation were ion specific and which ones were conductivity. For instance, the chloride strips that I explained in—we used during one of the slides where I went through the different steps of extracting the solution from the Bresle patch. Those are going to be ion specific and only measure chloride.

Lou: Gotcha. Carl Murray, by the way, did clarify his question the answer. “Is there an ISO standard number for garnet tests?”

Heather: There is a garnet standard for ISO, but I don’t know the number off the top of my head, but there is one.

Lou: Okay, so it’s one we can get to him offline.

Heather: Yes.

Lou: That’s fine. Eric is asking, “What is the simplest all-inclusive method for quantified testing of chloride ferrous ion and sulfate? In other words, is there one gauge or machine or a test that will handle all three of those?”

Heather: There is, and I… There is a test method that can do all three of those. I would like to contact him offline though because I don't want to get into specific manufacturers or proprietary information during this webinar.

Lou: Much appreciated. That’s a great way of handling it. Let's see here, what other questions have we got? Jim has suggested that there is a test that we may have overlooked—one from a company called CHLOR RID and something about CSN Salts Kit, which tests surfaces for chloride, nitrates and so forth. Was that a part of our presentation today?

Heather: You know what? I don’t believe it was in here. I will admit, yeah. That was not in here.

Lou: Gotcha.

Heather: So, that was a good thing for him to bring up. There is another test out there that can be used.

Lou: Excellent. I expect he’ll get with you offline to make sure that that gets included if this presentation makes it to the SSPC Conference in Tampa. So, let’s see what else. We’ve got time I think for one more here. “What methods are widely used for measuring soluble salts on large areas within a short period of time?” I know people with large projects have that issue.

Heather: So, what I hear from the industry and from the folks that are out in the field is that using the automated procedure tend to be a little bit more quicker and feasible for whenever you're dealing with large projects. But I really think that it’s about what the user prefers and which methods they like to use of the best. And again, it's important to know are you testing for conductivity or do you need to be ion specific as well?

Lou: Gotcha. Gotcha. Good. Well when we advertised these, we promised that we're going to try to keep it to 45 minutes. We know everybody has a very, very busy day. You are more than welcome to pop a few more questions in there. We will be able to handle those offline. Those questions are record for us, and Heather will have access to those. Eric, by the way, says thank you, Heather. Great job. I’d certainly say that as well. I think we've—we’re in a good place to suggest that this is a good way to conclude it. Heather, if folks in the audience want to email you directly, you’ve got your email address up there online. Is there anything specific about the best way to reach you?

Heather: If they could just put in the subject line that it’s tied to this webinar so that I know, and then I can make sure that I get back to them with whatever answers or questions that they might have.

Lou: That’s perfect. Wonderful! Alright, Heather, thank you. Thank you to all who attended. Thanks to SSPC for sponsoring this highly informative event.

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