Given the opportunity to ask any question about media blasting, most interested individuals ask about the application. Understand application, and you understand blasting.

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Given the opportunity to ask any question about media blasting, most interested individuals ask about the application. “When do you apply blasting?” “What situations call for which blast media?” “Why would one application be successful, and another a losing battle?”

Understand application, and you understand blasting. When asked, I find it best to use examples of applications to highlight the success of one blast process or another. When a restoration contractor ventures into the world of media blasting – typically using exotic, sometimes-uncooperative, blast media like baking soda, or dry ice – he never knows where he’ll end up. Some jobs are “textbook” blasting jobs: easy to see the proper application with very little question. Other applications require a little more ability to think “outside the box.” Experiences, whether first-hand, or gathered from others, help to guide our future applications.

Good examples, those filled with the proper information, can put you in someone else’s shoes to learn from their experiences – good and bad.

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The first example explores a “textbook” blasting applications. And although it may seem obvious to those of us with experience, it wasn’t to the contractor that tackled it as his first blasting application.

This application involved a major fire loss mostly within a large brick home in a beautiful South Carolina suburb (Image 1). After the initial tear-out, it was obvious that the home had severe fire damage throughout the structure. The fire took place on the second floor of the home with severe damage to certain areas of the roof and attic above.

Smoke and soot damage were widespread throughout the remaining roof, trusses, attic, the second floor, and to a lesser degree even the first floor. The restoration contractor – experienced enough to recognize the extent and severity of this loss – knew that a novel approach would be required.

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Simply covering up the problem was not an option. While coatings are sometimes applied following blasting, this is not the entire process. The proven approach utilizing “source removal,” or getting rid of the offending material, would be required. This method, traditionally using hand sanders and wire brushing, would have required weeks of extensive labor spent sanding and brushing.

The manual removal approach is tedious, expensive, and often lacks a truly effective end-result. Further, there were areas of the structure where tools like sanders and brushes would have had problems. Problem areas included portions of the attic with OSB roofing material and its thousands of protruding roofing nails, and the complex wooden framework of the home, interwoven with communications and electrical wiring. In fact, one of the experienced sub-contractors on the job recommended tearing out and re-building large portions of the structure, including the roof and attic – a viable, but very expensive, option.

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The contractor had heard of media blasting and its application in cases of large losses like this. He had also heard that the process would provide an effective end result with a drastic reduction in labor hours. Of equal importance was the fact that with a blasting process the tool never touches the surface, just the media which is “thrown” with compressed air against the surface, conforming to irregular surfaces, around nails, and into cracks and crevices – with no damage to modern wiring, or most building materials. Additionally, cleaning rates of 10 square feet per minute or more would allow for a much quicker job completion – pleasing a rather impatient adjuster.

After some consideration and research – including contacting a few of his peers for a recounting of their experiences – the contractor chose baking soda blasting for the application.

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Baking soda offered several advantages in this application. Overall, baking soda blasting equipment is much less expensive than dry ice equipment, as is the operating cost per minute.

Baking soda blast media also offers significant odor reduction. This media is a “buffering” agent, neutralizing the strong pH, and at the same time the odor potential, of soot and smoke residues. With proper, in-the-field training, the contractor was quickly up and blasting (Image 2). Areas of heavy damage were cleaned effectively using this process (Image 3). The baking soda even proved effective at cleaning the masonry on the exterior of the structure.

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In the end the contractor, the adjuster, and the customer were all very happy with the results. The contractor realized a healthy profit from a job well done, a stronger relationship with this insurance adjuster, and a good experience that would serve him well into the future. The adjuster was pleased with the turnaround time, and the fact that the roof and attic were effectively restored at significant savings over replacement. (Image 4). The end customer was also pleased with the quick pace of the job, and ultimately the results. About the only one who wasn’t pleased was the sub who thought he should’ve torn out and replaced that roof…

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In our second example, an existing customer, a landlord, had heard that his contractor had some new-fangled technology utilizing baking soda as a “sand blasting” media. This customer had heard the hype, but was it capable of blasting paint off of concrete without damaging the surface? A recent tenant in one of his rental properties had moved out and left something behind.

That “something” turned out to be an improvised basketball court on the back patio. A little red spray paint and this tenant was able to provide his sporting guests with not only a free-throw line, but a three-point line, a center-court circle and even a little support for the local b-ball team in the way of the “D A” graphics (Image 5 and 6).

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The contractor utilized the “wet blasting” function of the baking soda blasting system – something many restoration contractors don’t even know about. Still using compressed air as the blasting agent, water was added at the nozzle using an additional spray jet to control dust (Image 7). This addition of a small amount of water, typically between ½ and 2 gallons per minute, is all that is required to “knock down” about 90% to 95% of the dust created by the blasting.

One of the side effects to wet blasting is that the clean-up method must also be wet. In this case that meant rinsing with large amounts of water, easily provided by the same garden hose that provided the nozzle water. The water-soluble, baking soda media posed no environmental problems and was simply rinsed away.

Relying on assurances by the manufacturer that damage to the concrete would be minimal, the contractor used a “fan” shaped nozzle at 60 PSI to clean the lines and paint markings. It was then necessary to clean the entire patio lightly to match the previously cleaned areas. The entire process took less than half a day for the two-person crew (Images 8 and 9).

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Damage to the concrete was kept to the absolutely minimum and the results were very pleasing to everyone involved, with the possible exception of that odd future tenant that might want to enjoy a little pick-up game in the backyard…

Our last example took place just north of the border in Canada, but could be found in almost any part of North America. What sets this application apart is that it was a mold remediation job that was paid for by an insurance company that does not cover “mold” in its policies. Increasingly insurance companies are limiting their exposure to losses caused by mold damage.

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Whether they limit or deny coverage, promote and support regulations and litigation in their favor, or simply refuse to cover the clean-up of mold infestations, insurance companies are distancing themselves from mold remediation claims whenever possible. Mold damage, however, is sometimes simply too integral to the problem to be dismissed. The contractor involved in this example was faced with this situation: The lower half of an insurance-covered home was severely affected by mold and moisture damage from an illegal marijuana growing operation. While not widely known, many of these “grow ops” exist right in our own backyards. In fact, the more a grow op looks like a normal residence, the better.

One of the problems with these operations is that the indoor greenhouse that is created is very warm, and very humid – ideal conditions for mold growth. This is often coupled with the fact that grow ops are very often set up in properties where the operator grows for a “season” or two, and then moves on to avoid detection. Little care is given to the protection of the structures in these situations, and the mold damage left in their wake can be severe.

Such was the case here. And although the insurance adjuster steadfastly refused to refer to the damage as “mold,” he understood the need to remediate the structure of the “greenhouse damage.”

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The contractor consulted a few of his peers to gain their perspectives about the available systems on the market. He determined that a dry ice blasting system would fit his business – heavily involved in mold remediation – very well. The dry ice blast system did a fine job of cleaning the mold, the staining and chemical residues from the recent “operation.” The fact that the dry ice media would sublimate – turning from a solid pellet directly into CO2 gas upon blasting – was a big advantage.

When blasting with dry ice there is no secondary waste. In a job where “mold remediation” was officially not taking place, the less clean up (and the cost associated with it) the better. And while cleaning of the “primary” waste is still necessary, usually with HEPA vacuums, the amount of cleaning and volume of waste is significantly less than with other blasting methods.

As with many experiences there are things to be gained from failure as well as success. In this particular case, the lesson concerned the logistics of dry ice. Dry ice pellets are perishable and as such they are made to order – as much, or little, as you’d like. Order carefully because large boxes of dry ice can be difficult to handle on the jobsite, as well as back and forth. (Image 10)

Also, because of the logistical complexities of dry ice, purchasers tend to err on the side of having too much dry ice on hand rather than too little. Extra ice is never returned for credit. It’s never stored for the next job (Image 11). Extra ice is simply waste; therefore, estimate and order carefully.

Hopefully these examples have provided a little insight into the business of restoration with blasting. Blasting is like most tools in the restoration business: the more experience we gain, the better we become at our craft.

Experience can be our best source of knowledge. Ask around, “borrow” someone else’s experience, and get some of that important information. Ultimately, though, we have to get out and make our own way. In the architectural restoration business, one sure way to make things happen is with media blasting.