PAINTSQUARE BLOG

Who benefits from DOT's current specification practices? Everyone except the owners and taxpayers, it seems.

Owners, do you really need to specify down to the last mil? And do you realize the labor and cost implications of doing that?

A lot of time and money are wasted on continued coatings testing. Why test a new system when there are numerous ones available that we all know will do the job?

Adversarial project relationships are unpleasant and needlessly costly. Avoid them.

Comment from Kenneth Trimber, (3/25/2015, 9:29 AM)

Warren questions who is designing the coating systems being used by IDOT and states that they should identify coating systems that have more “wiggle room” during application. At the same time he states, “But why test anything for bridges, when there are thousands of successful bridge applications around the country to use as references for what works?” The logical conclusion to anyone reading this is that IDOT has come up with a unique system that’s nearly impossible to apply that isn’t used anywhere else, and where 1 mil is the difference between success and failure. The truth is that the IDOT system for field cleaning and painting is organic zinc/epoxy/urethane, a system that has “thousands of successful bridge applications around the country.” The tolerances in thickness are also the same that are used elsewhere. Regarding abrasive cleanliness, the SSPC surface preparation standards require that abrasives be tested for contaminants. For example, when SSPC-SP10 is specified, in paragraph 6.3 it states, “The blast cleaning abrasive shall be dry and free of oil, grease, and other contaminants as determined by the test methods found in SSPC-AB 1, SSPC-AB 2, and SSPC-AB 3.” The test methods in the referenced AB standards are oil and water soluble contaminants. This is a requirement of SP10, not something unique that IDOT came up with. If there are problems with the requirements of SSPC standards, contact the SSPC Standards Review Committee to voice the concerns. Note also that the development of standards is a very open process and SSPC is always seeking participation from the industry to make them better. IDOT should not be criticized for relying on industry standards when preparing their painting specifications.

Comment from Larry Muzia, (3/25/2015, 11:39 AM)

I agree about the requirements about abrasive cleanliness 100%, however, it is my opinion as a industry professional for over 30 years that the 20% low/high as the default for PA-2 is too restrictive and should be studied. On a 6-8 mil total dft spec can you really control a film to approx. 1 thousandth of an inch under/over on a complex structure.I recognize that PA-2 has higher tolerance catagories, however, as the default is 20% unless otherwise stated, it is my opinion that this needs further review.

Comment from woody woodson, (3/25/2015, 12:28 PM)

Its clear the guy is a journalism major and not an engineer or coatings specialist . He doesn't realize tight specs and proper application of those specs are what make a successful, long-lasting bridge painting project. Industrial coatings are all about the technology of the coatings and professional application. That will mean exact measurements of several things, in many phases of the coatings. If you want less specifications and regulations, the quality will definitely suffer.

Comment from Warren Brand, (3/25/2015, 6:16 PM)

Hi Ken, Thanks for taking the time to respond, I know you’re busy and I respect your time and comments. I’ve read your response a couple of times and am hoping you’ll have the time to respond again, and help me, and perhaps others, understand some things. 1. Why are coatings being tested for bridges when there is so much data available? 2. Is it your contention that organic zinc/epoxy/urethane is the best system for IDOT? Are there systems that would provide more value to IDOT in terms of either lower installed costs and/or longer service life? 3. Is there a risk, when specifying a generic system, that the performance characteristics of the various coatings will vary depending on the manufacturer and specific formulation? For example, if you tested 10 PU topcoats from 10 different manufactures, would you anticipate identical application and performance characteristics? 4. What % cost is paint of a total bridge painting project? Would it make sense, and be in the best interest of IDOT (and all DOTs) to develop a cost/benefit analysis of other, more costly materials, such as polysiloxanes, polyaspartics, calcium sulfonates, fluoropolymers, etc., or technologies, such as metallizing in combination with coatings? There are, I understand, two-coat systems that have preformed remarkably well. If we remove a single coat from a three-coat specification, that would reduce the application labor cost (and testing costs) substantially. Is someone doing these calculations? 5. Why isn’t IDOT, or other DOTS, using performance specifications? Or why isn’t there a national specification? There is precedence for this pertaining to Underground Storage Tank interior corrosion protection measures back in the late 1980s. 6. It would seem that there would be an “optimal” paint system for bridges (depending, perhaps, on their location and condition), yet each DOT appears to be struggling on their own, and spending a lot of money, to ascertain what’s best. Am I mistaken? 7. I understand the importance of clean blast media and I have the utmost respect for SSPC. IMHO, SSPC represents the best our industry has to offer. However, my concern was in reference to the use of ASTM D4940 – 10 and determining if recycled blast media was contaminated with chlorides. I just couldn’t figure out where the chlorides might come from after a bridge has been prepared for blasting and it seemed to me an added expense to IDOT with little justification or value. You closed your response by saying, “IDOT should not be criticized for relying on industry standards when preparing their painting specifications.” I’m not convinced. Is it your opinion that IDOT is doing the best job it can? Is there no room for improvement at all in terms of material selection and application guidelines?

Comment from Andrew Sedor, (3/26/2015, 7:38 AM)

Warren, I would agree there is an "optimal" bridge coating system. I think it would "optimal" would depend not only on location and condition but also variables and concerns that the owner of that bridge would deem important. Maybe cost is a concern that would make your opinion of "optimal" not feasible. What about time restraints, environmental regulations, or ease of application. Who will be applying these coatings? Sometimes it's a small maintenance crew with limited resources or skill. I want to pose a scenario for your question # 7. Understanding that in many circumstances chlorides have been coated over. In not the too distant past it wasn't common practice to remove chlorides prior to blasting. Even when we did start cleaning before blasting it wasn't really understood. Is it possible for blast media to become contaminated from chlorides that have been coated over in the past?

Comment from Kenneth Trimber, (3/26/2015, 4:00 PM)

Warren, you’ve posed a lot of questions. I’m not going to dig into them individually, but offer a few global comments at the 30,000 foot level. Coatings are tested because formulations have changed over the years to meet environmental restrictions (e.g., namely toxic metals and VOC), so much of the older data isn’t relevant. Also, all products of the same generic type, both within manufacturers and between manufacturers, don’t perform the same. So the specific systems supplied by the manufacturers are tested before being used. AASHTO NTPEP does a good job setting up a standardized protocol for testing bridge coatings. The results are available to states across the country when making selections, and NEPCOAT uses the NTPEP data to establish their criteria for entry onto their QPL. A review of the NTPEP results is a good first step in identifying candidate coating systems for state-specific use. The next step is to review the performance history of the systems in comparable environments. Since successful performance of the system is the ultimate goal, DOT’s often rely on those products that have proven to work well on the bridges in their state over long periods of time. Typically, systems that utilize zinc-based primers, an epoxy intermediate and urethane finish, have provided them with comfort that if applied properly, they’ll realize the long-term protection they desire. I know that states are in fact starting to use metalizing and polysiloxanes, and are considering 2-coat systems, but you’ll have to talk with them determine their willingness to deviate from the systems that have proven track records in their states in order to try out others. Batch testing is also performed to make certain the products in the cans at the jobsite are the same as the products that were tested and approved. Batch testing is done for good reason. No matter which system you select, there are going to be tolerances in cleaning and application that have to be met if they are going to perform. Good contractors are successfully complying with the required tolerances every day. Regarding the testing of recycled steel grit, take a look at expansions, scuppers, and splash zones in states where deicing salts are used (e.g. Illinois). You can see the salts, which is one of the primary sources of the chloride. The concern for these bridges is contaminating the recycled abrasive with deicing salts, which is why testing is important. My comment regarding not criticizing IDOT for their use of industry standards was in response to your comments on abrasive testing. Anytime you or anyone else specifies SP10 (or the other blasting standards), by reference you’re specifying abrasive testing the same way you’re specifying SP1 to remove grease and oil. DOT’s and others have every right to rely on industry standards in their specifications, including the associated standards that are incorporated by reference. If anyone has problems with the requirements in a standard, they should go to the standards organization to explain their concerns and ideally provide assistance in making changes. And finally, yes, I feel that IDOT is doing a very good job with material selection, and that both IDOT and the contractors working for them are doing a good job with the cleaning and painting of their bridges.

Comment from Gordon Brinker, (3/26/2015, 4:08 PM)

It they are testing and retesting the same systems that have always worked I agree that it's overkill. BUT with new technologies coming to market that offer not only longer life but are also safer for the environment and applicators I think the testing is very important.

Comment from Warren Brand, (3/30/2015, 9:09 AM)

Hi Ken, thanks again for taking the time to provide such a thoughtful response on the current state of affairs. Perhaps I'm a minority of one, but I believe there's a better, more economical means of addressing these challenges.

Comment from Warren Brand, (3/30/2015, 9:17 AM)

Hi Andrew, thanks for taking the time to respond and you bring up excellent points. In my firm, we almost encourage our clients to have us write "site-specific" application specifications precisely for the reasons you mention. Each site is different. You will be painting at different times of the year, will have different time constraints, workers, equipment, budgets, existing coatings, etc. Writing very long, complex specifications which try to encompass all contingencies is, in my mind, problematic. Specifications should be digital in nature, so that only those sections that are relevant for a specific asset can be pulled, but that's another blog I wrote (Driving Data from Disco to Digital, September 16, 2014) which also pretty much fell on deaf ears. Pertaining to your last question, yes. It is certainly possible for blast media to be contaminated form encapsulated chlorides from earlier coatings. But that question begs another: overcoating. I know it's a taboo word in the mainstream, but I believe it is a viable and oft overlooked solution.

Comment from Tom Schwerdt, (4/7/2015, 12:36 PM)

Warren: I can tell you the best performing paint system I've seen on Texas bridges in that 100 years of history (by far!): Red lead alkyd primer with an aluminum topcoat. Common to get 50+ years of service. However, we aren't allowed to use red lead in the paint anymore, we can't use nearly the solvent percentage used in those old formulas, and the supply of whale oil (plasticizer and wetting agent) available as an additive has rather dwindled. I am not joking about the whale oil. It was a significant factor in the performance. That's cut down the historical review to the last 25-30 years. Additionally, the savings of using a 2 coat system rather than a 3 coat modern system can be pretty small on field repainting of many bridges. Much of the cost is in mobilization, containment, lead abatement/blasting, removing containment, demob, etc. Once you get the bridge cleaned and primed, the added cost of a midcoat isn't really that much.

Comment from James Welter, (4/8/2015, 9:42 AM)

Warren, As a specifier for a State DOT, I always try to remember that I may not be the smartest guy in the room and hesitate to criticize others until I have "walked a mile in their moccasins". With limited funds,and dwindling resources, DOT's are constantly trying to make sure the most cost effective methods are being used to extend the service life of their infrastructure assets.As you are well aware, different coating systems may work better in different climates. Our state, like many other DOT's, has investigated the costs and service lives of different coating systems. Weathering steel, galvanizing,duplex, metalizing,calcium sulfonate,moisture cure, and the workhorse three coat zinc-epoxy-urethane systems have been used in our state. We are also investigating the use of a two coat zinc-polysiloxane system. Although the Red Lead and Vinyl systems provided good protection for structural steel, they are no longer viable options. The costs and expertise of the available contractors are considerations in the selections of structural steel protection systems. With smaller staffs,DOT's are going to more performance based specifications with ever increasing responsibilities on the contractors and suppliers for quality control. Recent test results are important for material selection for not only paint, but many other materials such as structural steel, concrete, asphalt, etc. Material sampling and testing are always a part of quality assurance.Every specification I have seen, provides ranges for coating dry film thicknesses. Is 20% too tight? Possibly, but that is the accepted standard. As for overcoating, the risk to the owner is extremely high. The data collection and interpretation of the condition and adherence of the existing coating is problematic.

Comment from Wayne Senick, (4/8/2015, 3:38 PM)

Part A.: Warren I respect your bravery in throwing open the doors to Pandora's box. One of the major problems in the infrastructure maintenance field today is the fact that people are focused on systems, standards, policies etc. as opposed to focusing on stopping the corrosion that's destroying our infrastructure from the inside out. In all the text, in the answers to the blogs comments above there is not one mention of the word corrosion. Corrosion is the reason we coat structures in today's financially challenging conditions. Effectively mitigating that corrosion should be the only reason that a coating system is selected for infrastructure maintenance. This in most cases is clearly not the case. If for example you review the NETPEP standards there is no reference to how effective the coating system is at mitigating the different types of corrosion which exists on the structures. Of course if were talking about a new bridge where there is no corrosion present these standards work quite well but as you so eloquently wrote those systems have been tested to death and we know that if you give us an SP-10 or in some cases an SP6 any barrier or sacrificial barrier coatings system is going to supply an adequate end result is long as somebody has not fudged the chemistry and delivered a different coating to the job then was tested. We know that fingerprinting and analyzing coatings from the job site is something that the DOT materials laboratories are doing because in some cases due to the low bid process people have to ensure their bottom line and the DOT's need to protect themselves to ensure their getting the performance as specified. As to the DOT's these people have to work under conditions which for most of us would probably give us a nervous breakdown. The hardest working of these of course are the Bridge maintenance engineers who on a daily basis have to go out there and figure out within all these rules and regulations how to keep those bridges from falling down. The TSP2 bridge preservation partnerships that have been established by ASHTO and the FHWA where Bridge maintenance engineers are finally being heard are meetings everyone should attend if they want to hear about how ingenuity and innovations with no money are being put in the place to keep our infrastructure viable. A great help to these guys would be for the specifications to be changed so that they focus is on the corrosion issues and the modes of paint failure that they have to deal with on a daily basis. The lack of interest in being involved in this discussion was brought to the forefront when the American Railway engineers sent out a survey of corrosion issues important to the railway maintenance engineer. This survey clearly identified 18 specific corrosion and paint failure issues that were of concern to the engineers. The survey was sent out to 300 coatings companies listed in the JPCL coating systems buyers guide as suppliers of the bridge coatings and they only received five responses in a four month period. The result of the survey has shown the engineers that there is a lack of interest in solving the structure critical corrosion and specific corrosion precipitated failures found on bridges by the coatings industry in general or maybe the survey was not sent to the right people in the organizations. I'm hoping that by reading this blog the industry will certainly get interested in focusing on stopping the corrosion issues as opposed to meeting the specs for the QPL. You may think that these two things are the same but this survey shows the exact opposite. The survey is available for any coatings company that is interested and we would be more than happy to invite your participation. Please contact the writer to get a copy.

Comment from Wayne Senick, (4/8/2015, 3:42 PM)

Part B: With 125,000 structurally deficient or functionally obsolete bridges in service today according to the FHWA it is time to seriously take a look at the process that exists for the preservation of bridges and structures. With stopping corrosion, being the number one goal. Any document that exists the talks about preserving a structure that doesn't have the word corrosion in the first sentence probably is not going to facilitate a solution. We need salt mitigation standards because salt is one of the biggest causes of structure critical corrosion. I respect the fact that people are testing for salts because they are the silent killer and will destroy any coating system if not mitigated properly. I think that by opening up the door as you have done we’re going to move towards a solution because Corrosion never sleeps and we are running out of time.

Comment from Warren Brand, (4/12/2015, 4:54 PM)

Hi James, thank you for taking the time to respond. My focus has always been on technical issues, and I am less familiar with the constraints imposed on you and the other DOTs, being public entities. I imagine it must be challenging. But there remains, IMHO, a fundamental flaw in the very fabric of the issue. For example, galvanizing is a slam dunk. Use it first and foremost whenever possible. (Anyone disagree)? Then when selecting coatings, start first with the most expensive portion of painting a bridge, surface prep. Find out what the most efficient, cost-effective means of surface prep there is, what aggregate to use, nozzles, etc., then identify coating systems that are in line with the surface prep. The entire process needs to be done systematically. Specifying a coating first, IMHO, is the tail wagging the elephant. And I've still yet to hear a compelling argument for ongoing testing. Yes, I've heard reasons, but I'm sure I'm missing some nuance. Anyway, I do appreciate everyone's time and comments. The takeaway for me, unfortunately, is that our firm will no longer be actively pursuing public works projects.

Comment from Warren Brand, (4/12/2015, 4:55 PM)

Hi Wayne, Tom, thank you both, also, for taking the time to respond. I know we are all busy, and I appreciate you sharing your thoughts. Kind Regards, Warren

Join the Conversation: