CoatingsPro Magazine

JAN 2018

CoatingsPro offers an in-depth look at coatings based on case studies, successful business operation, new products, industry news, and the safe and profitable use of coatings and equipment.

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Page 21 of 116

Notes From the Blog COATINGSPRO JANUARY 2018 21 with that short of a pot life. You really need to talk to the coating manufac- turer and see what they recommend for both the pump rig and the gun. You may need a heated plural rig with an exterior mix spray gun. A lso ask the coating manufacturer if they put up the material in caulking tubes, as those can be used for smaller jobs. However, it increases the cost of the already expen- sive material by about double. If you use a brush or roller, you will have to throw it away and get a new one every 9 minutes. And the finish on the material will look pretty bad. And it will probably not adhere very well to the surface. You can only trowel the material if it has been designed as a trowel-able material. And again, with a 9-minute pot life, you will have only 2 or 3 minutes of working time before you have to clean the trowel, or replace it every 9 minutes. I feel quite sure the product technical data sheet will tell you the equipment, temperatures, and spray tips you must use to have a successful project. Go to the material manufac- turer's website and get the specific information you need from them. Every reputable manufacturer of 100 percent solid epoxies has a technical staff that wants to help you. Call them before you accept the job or at least before you start! ere are not any quick and easy ways to do it. ere's only one way: the right way! Keep in mind, if you do not follow the instructions, the project will fail, and it will cost someone about 100 times more to fix the failure than it would have cost to do it right the first time. For instance, a plural rig to do the job might cost $50,000, while the consultant, laboratory, and legal fees to solve the failure will cost over $100,000. And that still does not fix the problem. It just lays the blame. A: T he best result for apply ing the coating is roller. You w ill have to change out roller pads w ith each new batch. T he great advantage to using a roller is the increased speed of appli- cation. Acceptable Soluble Salt Levels Q: W hen using the Elcometer 138, the salt conductivity kit, to check for the level of salt on the substrate, what is the minimum accept- able value that is allowed? A: is is the Bresle test. ere are too many variables to state a minimum salt level. As always, the correct answer to this question is to ask the coating manufacturer. One variable that most people do not take into account when using a Bresle test is how long the water was kept in the patch. Depending on how you run the test, extraction rates can be between 40 percent and 90 percent. Based on your signature file, I assume you are working on pipelines. If buried, I would assume you would be looking at salt levels of 3 to 10 µg/cm² (19.4 to 64.5 µg/in.²). If above ground, 20 to 50 ug/cm 2 (129.0 to 322.6 µg/in.²) may be okay. It depends on the environ- ment, coating system, and other site-specific parameters. Again, prior to "asking the experts," ask your coating supplier. If you have not established a good relationship with your coating supplier's technical experts, please take the time to do it. If you cannot find them, change coating suppliers. A: I believe this information on acceptable soluble salt level should be contained in the specifica- tion or otherwise addressed during the kick-off meeting. A lternatively, revert to the coating manufacturer's technical representative for advice. TSA Over Galvanized Steel Q: I have a client who wants me to apply TSA (thermally sprayed aluminum) over galvanized steel. Not too long ago, I was corrected, as I was steadfast about [not] applying TSA on a steel substrate. As it turned out, this isn't an uncommon practice. Once bitten, twice shy. I don't want to be steadfast on the application of galvanized steel only to learn later that this is also a common practice. I THICKNESS MEASUREMENT OF PROTECTIVE COATINGS Coating Thickness Material Analysis Microhardness Material Testing (860)683-0781 Robust, fast and reliable For ships, bridges, off-shore plat- forms, pipelines and structures Measures in accordance with SSPC-PA2, IMO-PSPC and others From basic "readings only" to stats and detailed inspection plans Surface Profile Measurement Easy and affordable ▪ ▪ ▪ ▪ ▪ ▪ Accurate and precise measurement of coating thick- ness with the Fischer FMP Series Re ad e r In qui r y at co ati n g sp ro m a m /i n q0118

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