Abrasive Blasting 101
Does your abrasive blast cabinet have a problem with excessive dust? Aside from lack of machine maintenance and regular service, there are many reasons cabinets can have excessive dust inside with poor visibility. These are some of the reasons that warrant a call to an abrasive blasting expert, like one of our team members.
You’re overusing your machine. First time abrasive blast cabinet buyers often purchase a machine with a limited Machine Duty Cycle to save money. These machines are designed for limited, occasional blasting. They do not have the support features to operate as workload increases. In fact, the machine gets messy and the visibility drops to almost nothing. When visibility is bad, machine operators generally begin holding parts closer to the window to see more clearly. This results in the window or window protector being etched, and ultimately the machine operator can no longer see the part inside the cabinet. When it comes to lower cost machines, users may not realize they are trading cost for lower quality high-wear parts like nozzels, abrasive hoses, windows, lighting, dust collector filters, etc. These items may need increased maintenance and replacement to keep the cabinet functioning properly – and those costs start to add up as the machine daily usage increases.
Real World Example
If you have an application for a blasting cabinet only requiring a daily duty cycle of 5%, about 20 minutes per 8-hour day maximum, a lower cost blasting cabinet will meet your needs. Overuse it trying to clean parts for more than twenty minutes a day and you will have a mess. Read this if you’re wondering whether or not an inexpensive blast cabinet is a good fit for you.
You lack a separator reclaimer to clean and recycle spent abrasive. The separator reclaimer is among the first items removed to make a blast cabinet less costly. Operating a cabinet without this feature is like driving a car without an oil filter. Yes, it can be done, but you’re going to have to do a lot more maintenance to keep things running smoothly.
ProTip: A separator reclaimer can’t operate as a stand-alone feature. When it’s eliminated to reduce machine costs, several other important items are also omitted.
Your Cabinet uses small Blower Volumes (cfm air movement out of the cabinet). These cabinets only have five to seven air changes within the cabinet per minute which means less clean air is pulled into the cabinet to replace dust created by the blasting operation. As a point of reference, to meet minimum air changes per minute for industrial-grade, high-performance blasting cabinets manufacturers must guarantee at least 20 air changes per minute. This is why so many inexpensive cabinets have poor visibility and create messy work areas; they have few air changes inside and a much smaller dust collector.
ProTip: A larger cfm blower can be used with a separator reclaimer because the separator removes dust and recycles the usable abrasive, which prevents abrasive escaping to the dust collector. Using a larger cfm blower requires more dust collector filter area to collect the dust and dirt without stopping blower airflow. It may help to think of it like a vacuum cleaner that can’t operate when the filter is full.
Real World Example
To understand how many air changes your machine gets per minute, divide the cubic feet inside the cabinet into the blower cfm volume. Note: most vacuum blowers only move about 90 to 100 cfm.
Your Cabinet has Poor Airflow Design. A small dust collector size, blower cfm and filter dust storage size, means a single air inlet filter. This creates bad cabinet airflow and dead areas inside the cabinet, which allow dust to escape each time the cabinet door is opened.
You’re Using a Small Gun. Small guns create much less frictional heat – and frictional heat is hugely important when it comes to abrasive blasting. Low frictional heat can mean the difference between it taking an hour to clean a part or less than ten minutes. Buyers beware: increasing the gun size isn’t necessarily the solution to your problem. Your gun cfm needs to match your blower size or you’ll end up with a huge mess on your hands.
Your application should determine which blasting cabinet you should purchase, not how much money you want to spend. Keep in mind that looking forward is part of any application. Try to purchase a machine that creates the most frictional heat possible and can scale as your business grows. When you’re shopping different manufacturers or models, be sure to pay attention to separator reclaimers, cabinet air changes, dust collector filter size, frictional heat, machine duty cycle, and other important features. Nobody wants to spend more on equipment than required but if you don’t spend enough for your application it’s money wasted!