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12 SURFACE PREP 2017 COATINGSPROMAG.COM system to grab onto, and achieving the proper surface profile is imperative to the optimum adhesion of a coating system. Surface profile is typically created through mechanical means, such as wet or dry abrasive blasting, shot blasting, or high pressure waterjetting. Abrasive blasting is a common method of creating a surface profile on a variety of substrates. When discussing abrasive blasting, it is important to consider the blast equip- ment and abrasive media that will be used. ARS Recycling Systems, Clemco, and Marco are among the companies that manufacture abrasive blasting equipment. According to Don ompson of Marco, blast pots hold the granulated material to be distributed through the metering valve into the compressed air stream before entering the blast hose. "Our Blastmaster M-Series abrasive blasting pot has a dual 'fail-to-safe,' pressure-release remote control system, with independent inlet and outlet valves that close when the remote control switch is deactivated. e Blastmaster Bantam abrasive metering valve has preci- sion metering capabilities for use with any abrasive and adjusts the flow of abrasive with a simple turn of the control knob," explained ompson. Flexibility is key in the abrasive blast- ing process, and sw itching between dr y and wet blasting w ith one piece of equip- ment is a relatively new development in the industr y. " T he Clemco WetBlast FLEX provides contractors an efficient system for ma ximum dust control on jobsites. T he FLEX is a portable system that combines a blast machine, a water tank, and an exclu- sive pump system to add water to the blast stream, outside of the blast machine. As its name implies, it offers the ultimate in f lexibility because the contractor can blast wet or dr y as his job and the environment dictates," stated Patti Roman of Clemco. T he ability to recycle blast media is another import- ant component of the surface preparation process. AR S manufactures mobile and stackable systems that recycle steel abrasives for continuous blasting operations. "AR S units retrieve, recycle, and reuse the abrasives quick ly, safely, and continuously to ensure a clean substrate for the coating process," stated Misti Gallo of AR S. Choosing the blast media is another factor contractors must consider prior to commencing the surface preparation process. Barton and W Abrasives are two companies that produce abrasive blast media. According to Joe Morris of Barton, the company recently introduced the MG1 grade to complement their range of garnet abrasive products. "MG1 is aimed at new construction applications, where thin coatings/mill scale and light rust are to be removed and where a deep anchor pattern is not required; 1.5‒2.0 mils [38.1‒50.8 microns] is the ideal profile range for MG1. A nything from steel and aluminum to concrete and brick are common substrates being blasted w ith MG1," stated Morris. Steel abrasives are another ty pe of blast media that is used for the surface preparation of steel and concrete substrates. "Steel shot has several advantages. Its specific mass is larger than expandable abrasives, so more energ y is transferred for cleaning, and steel shot lasts much longer. It is therefore a 'green' and economical product because it is recovered hundreds of times. In addition, we exclusively use recycled scrap steel in the production of our abrasives," said Iann Bouchard of W Abrasives. Abrasive blast media varies, as do the advantages and disadvantages of each for the various projects. W Abrasives offers steel shot. Other companies offer media made of garnet, glass, aluminum oxide, and sponge, for example. Industry associations, such as International Concrete Repair Institute (ICRI), offer guidelines to achieve the proper surface profile. Using Concrete Surface Profiles (CSP) replica chips and putty, contractors can visually determine the profile. Surface Preparation