Understanding Corrosion in Water Pipelines: A Guide for Pipeline Designers


Navigating Today’s Wet and Vapor Abrasive Blasting Technologies

By Wade Hannon | Published: June 15, 2017

Webinar Transcript

Evan: Welcome again to everyone joining us for today’s webinar on “Navigating Today’s Wet and Vapor Abrasive Blasting Technologies”, presented by Wade Hannon, Graco. Wade Hannon is an Area Sales Manager for Specialty Products at Graco, with expertise in equipment demonstrations and technical support. Through his more than 15-year career working with equipment companies, Wade has held a variety of positions including serving for three years as an owner-operator of Geo-Blaster. Wade operated Geo-Blaster Wet Abrasive Equipment in private, municipal and commercial blasting operations, maintaining the equipment and supervising training, and bidding projects.

Graco supplies technology and expertise for the management of fluids and coatings in both industrial and commercial applications. When Minneapolis based Graco began investigating the blasting market, equipment seemed like a perfect fit with the company’s history of moving, measuring, mixing, controlling, dispensing and spraying a wide variety of materials. After careful research of the pros and the cons of both dry blasting and methods of wet abrasive blasting, Graco launched EcoQuip 2 vapor abrasive blasting system. The vapor abrasive blasting method gives the operator more control over the water or abrasive mixture, which often results in reduced amounts of media expended. Not only does it use far less water than wet abrasive blasting methods (approximately 0.5-1 qt. of water per minute, the EcoQuip 2 reduces dust by up to 92% over traditional blasting, resulting in less containment and less clean up.

In today’s webinar, we will be navigating the market’s current wet and vapor abrasive blasting technologies. Methods of combining water with abrasive blasting to reduce dust that have existed for decades. New regulations to the abrasive blasting industry are forcing more companies to consider wet or vapor abrasive blasting. The perception in the market still remains that wet methods are messy, unreliable, and not much different than a wet slurry coming out of a blast nozzle. To combat these attitudes, manufacturers are introducing new equipment and technology to the surface preparation in cleaning markets.

The key points for today’s webinar will include:

  • Changes in the industry that have led to the development of new abrasive blasting tools and methods
  • Different types of wet abrasive blasting methods in the market
  • The difference between wet and vapor abrasive blasting methods, their advantages and disadvantages, and
  • Five things to consider before choosing your next vapor blasting equipment

As always, we invite our audience to prepare and ask questions throughout the webinar. We’ll be sure to reserve time at the end of the presentation to field any questions you may have.

Wade, welcome to the webinar!

Wade: Thanks, Evan! We really appreciate the opportunity for Graco to work with corrosionpedia.com on this.

Evan: Well, thank you so much, and we really appreciate you being here. I’ve taken a preview of the show, and it’s an absolutely great presentation you have planned for us.

Wade: I appreciate that very much.

Evan: Wade, when we were preparing for the presentation, you mentioned working with a shipyard as a transition from slurry blasting to vapor abrasive blasting. It’s such a great story and it shines a light on the importance of the technology to the industry. I’m sure our audience will be thrilled to hear about it.

Wade: Well, you know, one of the first locations—this is a couple of years back—that really got into it was Fairhaven Shipyard in Bellingham, WA. Now they’re a small to medium facility. Their main clientele is the US Government, doing full blast and painting vessels, mostly serving for the Alaska and Washington State ferry, but they do a lot of work for the Coast Guard, Navy and Army in that facility as well. And a small portion of the business comes from giving technically a shave and a haircut to commercial customers who can’t afford to do a complete blasting coat. They do a lot of abrasive blasting at that yard. Ninety percent of the ships basically have to be prepared and painted.

Previously, they were typically using what everybody else in the industry have used—water injection nozzles, halo nozzle, that type of wet blasting equipment, which I guess, we kind of call that slurry now. But again, the system is kind of far from perfect. You use a lot of water, you produce a lot of grit, and you’re going to wind up spending a lot of time washing, trying to get the surface clean to get that salts and chlorides off of that. In the end, there’s a lot of mud to clean up.

Now one big disadvantage with the slurry blasting is, you’re controlling the water at the end of the nozzle. The mud get flying everywhere, the blaster tries to dial the water down for better visibility, and that defeats the whole purpose. You’re just not getting the dust pressure that you need. And in addition to that, you have the weight of the garden hose on the nozzle, and the water in that garden hose. I mean, it’s contributing to operator fatigue. You know that production rate, really. They’re on the ocean and slurry blasting, you’re going to have to do a full containment on that—catch all the water, treat it. So it’s not only a mess, but it’s also a lot of increased work.

They were trying to find something that would bring more customers to the yard, make it more efficient, so a full blast was a more affordable option for some of these smaller ships. And they eventually came across the website for the vapor abrasive product line by Graco. When they saw that, they watched some videos. They’re used to having OSHA come down, so they wanted to see it first-hand. One of the videos that they saw was us working with Flatiron Construction to do an architectural blast on some of the concrete pillars on the new overhead rail system for BART to the Oakland Airport.

So, they agreed to look at a couple of high-capacity double tank units, which is our EQs2, and if they didn’t live up to the hype, they would be returning them. So, we went down. I personally went down, helped those guys fire up. We did a 300-ft. barge, was the first job. We did that with a lot less abrasive, a lot less dust, a lot less water. We did not create a huge swampy, gritty mud puddle. The water is controlled essentially in the pot, so by the time most of the abrasive is— the water is squeezed out from between those particles by the time it gets picked up in the air flow. Whereas, with this unit, there’s no tank to fill up. It’s just drawing from a standing tank to continually pressurize the pot with hydraulic pressure. You can hook a garden hose up to the unit, you can draw from a standard tank that you’ve got a premixed, whether it’s rust preventer or rust inhibitor in there as well. There’s several different options. You’d need less PPE. But again, the most important thing with vapor and wet abrasive is, you still need personal protective equipment. That is crucial.

With having to do the cleanup costs down there, they figured that by the time they were done, they were saving 25-30% on that. Not only that, I’m standing about 20 ft. from a welder as he’s doing his work and we’re doing our work, and it was completely safe.

Evan: Wow, that’s a great story, and it certainly outlines the importance of this technology to the industry.

Before we get started here on the actual presentation, we’d like to once again invite our audience to prepare and ask any questions they have throughout the webinar. We’ll make sure that we reserve time at the end of the presentation to field any questions that you may have.

Okay, as I’m looking through, it looks like our audience have all taken their seats here. So, Wade, how about we start the show?

Wade: Great! Sounds like a good idea. I’m sure everybody is anxious to get back to the business of earning money out there.

Evan: Perfect! Take it away.

Wade: Today on the agenda, what we’re going to do is, we’re going to have a good understanding of why the shift to the wet and vapor abrasive blasting systems in the marketplace, how each of them work, how they’re different from one another—because there are many that are different, what is vapor abrasive blasting, the five things to consider before purchasing wet or vapor abrasive blasting equipment. Now, obviously, at the end, will be followed up with a Q&A. In that case, if there’s some questions that we just don’t have that answer right now to, we will log that down. We will make sure that we get back to you with the proper answers.

First off is, why the shift to wet and vapor abrasive blast systems? Well, of course, the very first is dust suppression. This is something that the whole market is going after, and the main advantage of our vapor abrasive wet systems is up to 92% dust suppression compared to dry blasting. Less dust is a big thing in the marketplace nowadays. Big thing is the OSHA silica rule that’s come out, right? That’s a new rule, I guess, that we’re kind of put back another six months on that. But it was to take effect June 23rd here and is aimed specifically at crystalline silica, which is the most common abrasive out there. It’s defining a permissible exposure limit for crystalline silica that is 50% lower for general industry in maritime, and 80% lower for the construction industry than previous limits. And again, we’ve got that six-month little bit of reprieve so that enforcement will now start on September 23rd 2017.

The new EPA guidelines that are coming out: Emission Factors for Abrasive Materials, such as, you know, you’ve got materials such as the coal slag, garnet, copper slag. They’re generally used to cleaning metal surfaces, removing rust and preparing the surface, getting a good profile before the application of a coating. Pre-blast and post-blast abrasive materials contain traces of heavy metal such as chromium, magnesium, nickel. We’ve even got some of the products out there that have lead, arsenic. So, there’s a lot of different products out there that they’re starting to go after because of the heavy metal issue. We’ve got leaching in the ground water from some of these materials, as well as health risks from using the heavy metals to blast.

There’s a lot of “green” initiatives coming along within companies. I think everybody is trying to get to that next step of doing something different and trying to be less impactful on the environment. You know, company, health and safety plans are changing. You’ve got increased health insurance, increased liability insurance, increased workers’ compensation. In some areas, like you’ve got California, they’ve got a cap and trade system for their carbon taxes, and everybody is competing for younger talent nowadays, which can be extremely difficult itself.

What we’re going to go into here is a little about the different types of what abrasive blasting methods: WIN and Halo nozzles. You can see a WIN nozzle which is really a water injection nozzle that injects a stream of water near the end of the nozzle. Some of them actually do that at the bottom of the pot as well, but the result is essentially the same. And you’ve got jets of water that just dampen the abrasive as it leaves the nozzle. These are pretty well the standard of what was in the industry up to, you know, really in North America, the last five to seven years. The next is a halo nozzle. As most of you are aware, there’d be a water ring that just goes around the blast nozzle and creates a curtain of water, and that dampens the dust after impact as well. These nozzles, both of them, are bought and added to dry blast systems, so it is fairly economical.

As you can see, your pros are: relatively inexpensive, and you’re suppressing 50-85% of the dust, roughly. Cons: high water consumption for dust suppression. You know, you could be anywhere from a gallon to 3 gals/min, depending on what you’re doing, how much material you’re throwing out there, and how much dust you need to suppress. And you still got that high media consumption rate that you would with the dry blast type units. So now, not only are you using that 600, 700 lbs./hr of material, but you’re also going to save 50-60 gals+/hr.

Now, with a wet abrasive blaster, the water and abrasive is stored in a pot, and that’s stored under air pressure. So while the material is mixed together in that pot—and it does give you some effective dust suppression—you have limited flow control, and you still have a high abrasive and water consumption rate in comparison to the vapor abrasive. As you can see from the image there, this is essentially what you’re getting, which is you’re getting a material that is just almost like a Venturi system. It’s just dragging out whatever mixture is in there.

Now each wet system reduces dust, but there are drawbacks and potential problems with several, or there were. Over time, a lot of these drawbacks and problems from the older technologies led to a lot of mess. It’s too wet, I can’t get the production rate, it’s way too messy, I’ve got too much clean up. This really changed with the vapor abrasive blasting.

We’ll get into a little bit about what exactly is vapor abrasive blasting. Why do they call it vapor abrasive? Why don’t we just call it wet? There is a reason and a thought behind that. We combine the water and abrasive in the same pot, but we create water pressure in that pot, not air pressure. So, it’s literally the hydraulic pressure on top of your material that is squeezing that material down. And again, before it gets picked up in that airflow, you’ve squeezed almost all the moisture out of it. So, you’ve got a wet particle that’s hitting the surface. It’s got more mass; it’s got more momentum. These are some of the reasons that we can get that same type of production rate, the same profile, with a smaller grain of material, and also with using a lot less material.

You can add some of the rust preventers or Inhibitors directly to the pot while you’re blasting steel. What this does is, it really removes a lot of the salts and chlorides from the surface, which is a problem that you’re getting when you run into a flash rust situation.

One thing I want to mention that I haven’t got in here is, there are from SSPC and NACE that talk about wet abrasive blast cleaning standards. This is something that I think is important for everybody to get because when you look at your dry blast situation where you may have an SP10, you may have an SP5, whatever you need to get to in a dry situation is not necessarily the same wet when we look at the visuals of it. So it’s very important that we talk about surface cleanliness using the wet systems because that tends to wash and hydraulic a lot of that material salts, chlorides off. And of course, it just helps immensely if you’re using a rust inhibitor or passivator or preventer.

Now the big issue with pros here is, you’re going to get up to 92% dust suppression in comparison to dry blasting. With this system, we also afford really fine control. We can turn that air blast pressure down to 30 PSI. I can nearly turn the water and abrasive completely off. So, I could dial down and use 70 lbs/hr on a real light restoration job at 30 PSI, or I can crank that up to get a full production value of the same type of production rate as sandblasting, using less than half the material. So, it allows for a wide variety of surfaces that we can clean.

A little bit of a closer look. The system will remove any coatings, contaminants corrosion and residues from hard surfaces, and it would do that in a more efficient, cleaner way than your typical dry blasting will, and in comparison to a lot of the types of slurry blasters that are out there as well. Now this is similar to dry blasting, but again, we’ve got the material moistened prior to impact. So, once that fragmentation happens, a lot of that extra particles are already wetted out and typically hit the ground very quickly. We optimize our airflow and water usage. We only use roughly—I would say, on average, probably 1-2 pts/min. And if you run in a real low production or doing something very delicate, probably even less than that.

Now you can utilize any type of blasting material that is going to sink in water, except steel shot of course. So you have a wide variety of material that can be used without a doubt. You know it works with garnet, crushed glass, glass beads, coal slag, copper slag. I used walnut shells last week for a customer demo. And of course, soda which is a nondestructive material. And the wetness of the blast is a function of the media size and shape. For instance, if I’m using a 2040 garnet, I’m going to have a lot more water in between each particle than I would if I was running an 80 grit. So, the thicker the material, the more water you’re going to see in the blast; the finer the material, the less amount of water.

There’s five things to consider when selecting the wet or vapor abrasive equipment. How simple are your controls? Are Infield adjustments required to maintain consistency and performance? Do you have support from the manufacturer? And most importantly, the manufacturer’s distributing network, which is really key for contractors out there in the field. There’s nothing worse than being out in the field and having to run around for 3, 4 hours trying to find a an O-ring. You’ve got, where are the equipment and parts manufactured? There’s a key thing. I mean, Graco is a very proudly American company, and we have a distribution network unlike any other supplier out there in this industry, and we also have excellent warranties on all of our products. It’s crucial to we make sure that we take care of the customer, and that’s what we strive to do every day.

When we’re talking about water usage, let’s look at the specs to determine how much is actually used. You want something out there, a machine that’s going to use as little as possible. And in a lot of cases, you’re not even going to see any water run off of this machine. And obviously, depending on the local humidity, the local temperature, a lot of times, that’s evaporated so quickly that you really don’t see any. You’ve got less containment and less cleanup using this. And that translates not only of course to less containment for a major portion of blasting operations, but you’re less cleanup, and with cleanup comes disposal. We’re working with a customer on a lead abatement job right now, and that’s one of the biggest things is, if they were to come in there and use a water ring and that type of paint, well, you know now you’ve got 600-700 lbs/hr of material, plus the water, to dispose of; whereas, we’re probably going to be looking with our system somewhere around 250-300 lbs/hr, and about 15 gals/hour of water, especially when you’re dealing with something that is a product like a lead. That’s going to be very expensive disposal. So, this can really help with those kind of costs and maximizing your profit as a contractor.

I would definitely say wherever you’re at, get a hold of a Graco rep, see a demo because you’ve got to see it to believe it. I can tell you anything, we can all talk about all of this stuff, but once you see it, you’ll believe it. You’ll understand why it is so much different than the typical wet type system.

Third is our media usage. Media can be extremely expensive in some cases. I mean if we’re talking about glass bead, plastic media. I’m going to be doing some good testing of plastic media here next week, so we’ll be able to kind of update you. Anybody that’s interested, throw that question aside, and we’ll get back to you on that.

When you want a machine that uses a lot less, does a great job, and is easy to run, because let’s face it, we all know as contractors out there in the field, you may get a call from one of your guys at 2 in the afternoon saying, well, it hasn’t been running since new. That’s just part and parcel of being a contractor and having employees. Make sure your machine has great control of media usage. You know, modified dry systems are very hard to control the media usage. You’re really running a Thompson valve, so you’ve got to have a lot of material running through there because it’s fighting itself to get to the surface and do its job.

You want to make sure that the machine handles coarse and fine materials. The new EcoQuip 2 uses a pinch valve type system with our own proprietary house in there. Not that you can’t use a regular piece of blast hose, but ours have been designed for longevity. Make sure you’ve got something that’ll go from 12-150 grit. If you don’t have a pinch valve in there, you’re not going to be able to get a thick material through. And there are some out there that are using Saunders valves and some of that older technology that obviously, Graco went to great lengths to some engineering work and determined that the pinch valve hose was the way to go.

And you don’t want media to be sensitive to moisture in dry pot based systems. I’ve got one customer who I think last year got an extra 65 days a year just because he was sending guys home. They’re blasting under a tent, but it was raining out. The humidity was too high. They were clogging up. So, they didn’t have that problem with the vapor abrasive system. And it was kind of interesting to get his take. It more than paid for itself just to be there for those days alone.

The other is blast performance. What are the removal rates like? How’s the machine compared to dry and wet? Can we verify these? We’ve got an engineer blaster—our engineers here at Graco went to great lengths to make sure that we smooth it out, so there was no CFM loss. The machine has got a very smooth consistent pattern.

Removal rates… you know, we can get into that. Those are some variable. How many coats of paint, how many mils? What type of material is on there? What I definitely will say is we can go toe-to-toe with the dry blaster all day long using a fraction of the material.

Dust suppression. Don’t take claims at face value. There are companies out there who claim 100% dustless or dust free. All I can say to that is ask for an air quality control report because that scientific proof with their claims are actually real. Don’t take a manufacturer’s word for it. Get a third-party report, so at least that you know where you’re safe. And there’s no such thing as dustless or dust-free in this industry. The fact is, if we look at air quality control reports and the way that those studies are done, any of the dust that is kicked up by the compressor air itself, the ambient dust, it’s considered to be dust from the process. So again, make sure that you check, you look through this.

How did EcoQuip 2 rate in these five areas? Well, we’ve got really easy-to-use system now. Pots automatically pressurize themselves. The pots are—so once you get up to the top and you filled that pot with water, you close it up, and that pressurizes automatically because there’s no air left trapped in the pot. We’ve got much simpler controls. And probably one of the best things that we’ve put on there was an abrasive meter media track. That just counts our pump cycles per minute, and that way, I can tell if I’m going to be doing 40 PSI and some very delicate work and I’m using soda, I’d probably only want 3 or 4 CPM on the top. If I’m running at 120 PSI and fully cranked out, I’d probably want 15 CPM on the pot. Where this really comes in handy is, you’re going to be able to have your guys on site. They’ll know what the last job was. You can take some of those details. You know, maybe I did that a month ago, but you can look back in your paperwork and you can know that while I used this size of material, I had this many cycles on my blast pump, this was my blasting pressure, and you’re done. So, it’s a very user-friendly machine out in the field. And you’ve got, of course, using media loading and handling. We’ve got the cone design to drop that abrasive as quickly as possible down into the pot.

5-step Quick Start process, which is posted on the pot of each of these machines. So, while they’re out in the field, your guys are able to go through this very quickly—even to the new guys—and it’s pretty self-explanatory. You hook up your blast hose. You can fill the pot with abrasive, top it off with water, set your blast pressure, open up your abrasive media flow, which comes from the pot, and you go to the surface, you blast and you set your media track system.

How did EcoQuip 2 rate in these five areas? The low water usage, it is documented and known. We use 1/2 to 1 quart/min. We have the ventless pot. The below chart kind of compares the EQm with the EQp. And as you’ll see in the next few slides, our EQm is a mobile unit with a 3.5 cuft blast pot, and our EQp is a portable unit with a 2 cuft blast pot. This kind of of gives you an idea on the different rates of CPM for the EQp as compared to the EQm, and especially going with different grit sizes from 80, 30/60, down to 16/40. So, we’ve got a lot of this information that we provide to the customers so that you’ve got everything you need when you get out on the site.

We’ve got low media usage. Quicker and easier to set and monitor than abrasive consumption rates. Again, this is kind of just going back and highlighting what we’ve talked about. You’re handling both coarse and fine material from 12-150 grit. The smallest model, which is our EQp, the portable. It’s 2 cuft pot—it can blast for up to 90 minutes, depending on your settings. So that’s pretty phenomenal time for a small 2 cuft pot.

Our performance is equal or faster to removal rates compared to dry blasting. And again, if you want to crank this up and use 300-400 lbs/hr, we can go faster than dry blasting at 600 or 700 lbs/hr. We’ve got the engineered blast circuits so you don’t have very much pressure drop, if any at all. I think it winds up being about 1 CFM. And you’ve got an increased max blast pressure from 120 to 175. I mean, let’s face it. I don’t know too many guys who can get out there and hold on to 130 PSI nozzle, but what we’ve done is that the pots are now certified to 200 PSI. That gives us a great amount of head pressure to make sure that our blast is very consistent and smooth. And that’s one of the keys out there. That was a big change that made a difference with the vapor abrasive.

We can handle both low and high airflow, and we handle, again, very coarse and fine materials at the same time. That’s just all going to come down to adjustments, pressures, media track settings between, say a 12 grit and 150 grit, but we can easily walk you through that process if that’s something that comes up.

This is our third-party dust suppression report. We at Graco only make claims we can substantiate. That’s a key thing. I always use that term we use our secret weapon; it’s called the truth. Yeah, you really can’t go wrong there. So, with our third party testing, and that was through Applied Environmental Sciences in May 2014, we did the comparison study of airborne particulate produced by vapor abrasive versus dry abrasive. We had three different types of media. We used garnet, we used coal slag, and we used crushed recycled glass—3 sets of samples dried and weighed to measure particulate mass production on each run, and we found up to 92% dust reduction on steel in comparison to dry blasting.

Here’s a picture of some of the EcoQuip 2 models. I’ll go from the top left over to the right, and then we’ll go down on the bottom. Top left is our EQp or portable unit with a 2 cuft blast pot. That machine is designed to run on anything from a 70 CFM to a 375 CFM compressor. Again, nice simple blast controls, and it’s a very portable machine that you guys can put into the back of the truck and take out. You can get it up an elevator if you’ve got some tight spaces.

Then we’ve got in the center top our EQm, as we call the mobile. That’s a 3.5 cuft pot. That machine is designed to operate on compressors from 185 to 500 CFM. Excellent little unit. Productivity is fantastic. It’s just a little easier for guys to get around at if you’re doing driveways, things like that.

Once we get into the EQs systems, which is our right hand top layer, that is a 6.5 cuft pot. Those machines come with 110 gallon water tank in a crash frame forkliftable from both sides. Those machines are typically what start to see in high production areas—shipyards and heavy industrial oilfield, that type of thing. You can also—if you have your own trailers and that type of thing—you can get the OEM version of that which is a pot and panel. So you can fit that right into your existing equipment.

Lower left, we’re looking at the EQ 2S. This is a dual pot model. This is really, really big and heavy industrial and shipyard applications due to the fact that you now can have two nozzles working at the same time. We did some extensive testing over the years, and we found that the only way to make sure that there’s really a true good consistency in both lines is you’ve got to have them coming out of two separate pressure vessels. So, that’s why Graco has designed that dual pot system.

On the lower right are our mobile units, or trailer units I should call that. You’ve got two different kinds. We have both 6.5 cuft pots and panels on these, but one is available with a 200 CFM compressor; another is available with a 375 CFM compressor. So it really just kind of depends on your applications and what you’re using. Great unit, very well-built, heavy duty.

One of our educational resources that the we tried to bring out and just educate people in the industry was blastjournal.com. This was essentially brought out so that we could give a forum and an area for people in the blasting business to really understand what vapor abrasive and wet abrasive was all about. So, it’s a fantastic resource. We’re doing articles every couple of months, and we make sure that those go out. So please, take a look at the Blast Journal, check into some of the articles that we’ve got. It’s from a new guy getting into the business. We can help you there, or we’re putting article out how to write your Google Adwords properly, how to design your website properly, how to bid on a blasting job, how to contain a blasting job, right up to some of you guys out there have been doing this for perhaps since. So, you may not need those resources, but we’ve got plenty other resources on there as well that can help out. If there isn’t something on there, send us an email. We’d be happy to get your feedback and try and get some of the more detailed information for some of the more experienced blasters.

That kind of wraps up where we’re at, and again, if you want to request a demo, just go to graco.com/ecoquip. There is a link on there where you can hit that button, and you can request a demo. We have demo text pretty much covering all of North America. So, thank you all very much for being here. Thank Corrosionpedia for having us. Now we look forward to some questions.

Evan: Hey, Wade! Wow, thanks for powering to that presentation. It was really informative. And to the audience, I want to remind you that we’ve already had a number of questions coming through, and we’d like to encourage you to ask any questions that you may still have. Wade, if you’re all ready, I think we should jump right into these questions here.

Wade: Good to go.

Evan: Perfect. The first one comes from John, and he asks, “How does the EcoQuip 2 stand up to cleaning galvanized grating?”

Wade: It works fantastic. As a matter of fact, I just got back from Texas here a couple of weeks ago, working with one of North America’s largest galvanizers. They have several of the machines in their production lines and several mobile units that they actually use out in the field. So, great product to be able to do that. You’re just going to have a situation and what type of material to use.

Evan: Perfect. Alright, we have another question here from Jordan who asks, “What variables affect how much water will be used when blasting?”

Wade: The biggest variable is the grit size, the material. Again, if you’re going down to a 1220, 3060, that’s what’s really going to be the variable. The thicker the grit, the more water you’re going to see in between the particles, the more water you’re going to be running through. If we’re running an 80 grit—even a 60 grit— most of that is compacted by the hydraulic pressure in the pot. So by the time that gets picked up in the airflow, there’s really just a mist left, which is one of the reasons why we call it vapor abrasive.

Evan: Perfect. Alright, we have one here from… I want to make sure I pronounce his name right, and apologies if I get it wrong, but who asks, “Can any of the equipment fit tight manholes? Example, 20 or 30-inch manholes.”

Wade: No, but what I would suggest in a case like that—and I think I know what you’re getting at—so the first part of my answer will be, you can run a lot of blast hose with these machines. The second to that is, if you’ve got something specific, we’d be happy to look at that as a particular option. We have a lot of distributors who do some custom build on that. So, please, by all means send me an email if you’ve got some specifics, and I can try and help you in the right direction.

Evan: Perfect. Alright, we have another here from Brian who asks, “How long can you last before refilling the pot and water tank on the various EcoQuip models? I saw the EQp will blast for up to 90 minutes?”

Wade: Yes, that’s correct. And then, if you go up to the EQm, again, it kind of depends on what water source you put to it, but you’ll be about 13-15 gals/hr on a EQm. It’s a 3.5 cuft pot. If I was running, say a 60-80 garnet, I’d be getting 2.5 maybe 3 hours of blast time on that, running through about 45 gallons, 40 to 45 gals/hr of water. When you get into the 6.5 cuft pot, then that’s relatively variable. It’s an easy 3.5+ hours with that. And I’ve seen guys have those dialed down and last for 6, 7 hours. So, it’s really variable. What do you have to remove, what pressures are we at, and how hard do we have to hit.

Evan: Perfect. Thank you for the answer. I have another one here from—again apologies if I mispronounce your name, but who asks, “Compared to wet blasting, how much does vapor blasting reduce airborne particulates containing toxic metals, i.e. lead?”

Wade: That’s an interesting question, and this is going to be somewhat shooting from the hip, but I know that if we look at the typical wet type systems were somewhere between 50% and 80% reduction; whereas, ours does get up to that 93% reduction. This is going to have something to do with the type of material you’re using to blast. Obviously, your Garnet is probably the cleanest material out there to blast. Next down would be your crushed recycled glass. So, there are some variables there.

Evan: Perfect. Well, we appreciate the answer. We have one here from Luis from Honduras, coming in from, or he’s here from the South. “Any problem with inhibitor rust additive in water or only portable water?”

Wade: It needs to be in potable water, absolutely. So, you need to have a fairly clean source. Now having said that, I have many customers down in Florida that deal with the same type of issues, very high calcium content. You know, I have to flush those machines regularly because of it. They use the rest inhibitor regularly. Well, I can’t really answer that specifically. You won’t see a big issue with it, but you should use potable water.

Evan: Okay, we have a question here from Amy who asks, “How do you prevent flash rusting with vapor abrasive blasting? How long will these chemicals be able to surface?”

Wade: Sure. And there’s a few different types, so I’m not going to go into specifics on the ones out there, but you’ve got surface passivators, and you’ve got preventers. Typically, you can mix that in with the water, they’ll be anywhere from 50:1 to 100:1 mix ratio, and those can prevent flash for up to 72 hours. Obviously, that’s in ideal conditions, with no rain and that type of thing. But up to 72 answers—er, sorry—72 hours is the answer that I have.

Evan: Alright, looks like we’ll be rounding 72 answers to these questions as well here. So, we have lots, lots more on the way. A question here from Ronaldo. How is it different from the quill blast units that are presently in use in offshore maintenance industry?

Wade: The theory is the much the same. What we do is, we use more generic parts—easier to get a hold of. And again, we’ve got a distribution network second to none. But the theory is the same as far as pressurizing the pots with water. We just have a finer control over our ability to blast; our production rate far exceeds as well.

Evan: Okay, we have…

Wade: Oh, and let me add to this. We do have an Apex certified machine, Ronaldo.

Evan: Perfect, question here from … “What about collection treatment and disposal of used up water grit slurry?”

Wade: You know, I’ve got some customers who do a lot of lead work in tank farms, and what they’ve done is they actually used a little extra water, they designed a drip tray systems. Everything went down into the drip tray, and they vacuumed it out and went and disposed of it. There’s different products depending on what you’re doing. For instance, in the lead world, you’ve got several products that are designed to prevent the lead from leaching once it’s been blasted, so it can be disposed of nonhazardous. So, there are the options there that we can help walk you through.

Evan: Okay, a follow up here is, “Is there any way to reuse the spent water from the grit slurry?”

Wade: Yes, I’ve seen it done, but the fact is, you’re using so little of the material that it’s hardly worth your time to do that.

Evan: Perfect. Okay, we have a question for Mike. “What are the acceptable levels of dust in the air quality report?”

Wade: Well, that really just depends on your different States, your different local governing bodies, the EPA. So, it’s somewhat variable.

Evan: Okay, perfect. Well, it looks like we are out of questions coming in here, unless there are any that come through in the next minute or so. If anybody has any other questions, I’m sure Wade would be happy to jump in here and answer. Wade, is there any other issues that you’ve often encountered, questions you’ve encountered that you’d like to make sure everyone knows the answer to.

Wade: No, you know I think everybody’s answered the typical questions that we get, which are of course all the concerns that everyone has out there when trying to switch to a whole new process. But again, we’re here to help, we’re here to answer any questions. So, if people have any questions, you can email myself at [email protected]. I would be happy to answer those questions or get the answers for you if I don’t have them.

Evan: Perfect. Well, we have a couple more that have come in. Maybe even in a few more, all we had to do is ask and they just come rolling in. Joan asks, “Is there any ricochet benefits compared to dry abrasive blasting thing?”

Wade: Yes, it’s massively different. You do not get the deflection the way that you do with dry blasting. I always see that when people will come up behind a demonstration, and they’ll be standing there 10 ft back, and they’ll kind of inch their way in, and there’s a look on their face like, man, nothing is coming back up. So yeah, big difference.

Evan: Okay, and a follow up question to that from Jamie. “What is the ricochet distance when trying to protect. What do you typically see is the actual distance there?”

Wade: I typically—you know, I don’t have it specifically, but I typically see that everything drops within 10-12 ft of the blaster himself.

Evan: Perfect. Alright, we have another here, “What type of surface profile can we expect compared to dry blasting?”

Wade: I’ll get you any surface profile you can get with dry blasting, and I’ll do it with a finer material. For instance, if I need to have a 4 or 5 mil profile, I’m going to be using a 30/60 garnet. If I need a quick 2-3 mil profile, I can use an 80 grit garnet. So, what’s happening there is, those particles again or wetted out, they have more mass, they have more momentum, they do more work.

Evan: Perfect. Okay, well, we have another here that says—I think this one is fairly specific and related but—“We need to protect galvanized grating 6 in. from the blast surface.” I’m not sure if that’s a question or a comment, but I’ll let you address that one.

Wade: I’m assuming that you don’t want that galvanizing to be taken off. And in that case, there’s options. A lot of times, I’ve got customers who, they’ve got a sensitive area will actually use some corrugated plastic sheets cut out properly as a template, and that’s a fantastic way to do it because it’s light, they’re easy to work with, and you won’t get through them.

Evan: Perfect. Okay, we have a question here from Robert, who asks, “How well does it work on coal tar epoxy coatings on pipelines?”

Wade: It works great. Works fantastic, and you just let me know, we’ll come out and prove it to you.

Evan: Perfect. Nice and easy.

Wade: And the reason that—let me add to that. The reason for that is, while the surface temperature doesn’t change because of the moisture in there, we’re not creating a heating issue. Which means that we’re not balling that up and trying to move it off much kind of like powder coating.

Evan: Perfect. Alright, we have another one here from John again, related to the ricochet question. “In reference to the ricochet question, can ricochets be used to assist in the cleaning?”

Wade: I have seen where we’ve been doing some concrete work delamination, and we’ve been able to pin back at the rebar using our equipment, where it was a lot more difficult with the dry blaster.

Evan: Perfect. Okay, well, it is almost 50 minutes in to the show here. And once again, we’ve ran through our list of questions. Wade, the one that I know you addressed earlier, but I think it’s the perfect place to end this presentation off with is, if people have any more questions either later this afternoon or sometime tomorrow, what would be the best way to reach out to you with those questions?

Wade: That’s going to be my email address, and I’ll bring that up again, which is whannon. So, [email protected].

Evan: Perfect. We will make sure that we include that email in the follow up that we send to all of our attendees who’ve shown up here today.

So, on behalf of Corrosionpedia and Graco, I would like to thank everyone who has attended our webinar today. Thank you for the great questions and the great attentiveness throughout the show. We look forward to seeing you all come back some other time, and we look forward to helping you with any other questions you have in the future.

Wade, anything you’d like to say to our audience before you go?

Wade: I want to thank everybody for taking the time to be here. We really appreciate the interest in what’s making this different. I want to thank Corrosionpedia.com for giving us an opportunity to have this platform and work with them. We’re really excited to do that in the future.

Evan: Perfect. Thank you so much, Wade, and thank you to everybody else. Until next time, we will see you later.

Wade: Thank you!

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