The Insider’s Guide to Buying a Blast Cabinet:  Ten Often Overlooked Tips

 

Blast cabinet purchasing decisions are often based on the size and price of the machine.  Is it big enough for the parts I need to blast, and is it affordable?  Because many machines are inexpensive and there isn’t a lot of awareness of potential pitfalls, you often discover too late the offsetting costs of performance, labor and maintenance, amongst other problems.  So to make a wise decision, keep these factors in mind:

 

1. How much blasting will be done?  Once a blast cabinet is installed, you may be surprised how much use it gets.  If it turns out that you blast more than three or four hours a day, you can save a lot of time (and time is money of course) investing in a better machine.  Or, sometimes a simple equipment upgrade to the existing machine can work wonders.  A vendor’s test lab can determine blasting cycle time, and iron out which equipment selection delivers the best return on investment – before investing. 

2. What media should I use?  If you are not locked into a spec, work with a local distributor that carries a wide variety of media – and has a well equipped lab.  Fine, aggressive, dense, lightweight or dust-producing media dictate special equipment considerations.  Media is key to performance.  Time spent developing the blasting process – before a machine is purchased – is time well spent. 

3. Equip it for the rigors of blasting.  No two ways about it, aggressive media such as aluminum oxide wears out the equipment.  Having the machine made from the right materials in the first place can bolster durability, while minimizing labor and downtime.  Include rubber linings, heavy duty hoses, and boron carbide nozzles. 

4. Do you need to address potential problems with your surface finish?  Too rough a prep can result in too much coating being used – and coating failure.  Traces of iron in the blast media can cause stainless steel parts to rust.  Embedment of aluminum oxide shards can cause delamination of flame-sprayed metallic coatings.  Each of these is easily overcome with the right preparation. 

5. Speaking of finish, keep it consistent!  Quality blasting processes eliminate the problem of too many variables.  Sure, blasting is a robust, versatile process and tweaks to a dozen or more variables can “tune in” the process to exactly what you need.  But when those variables wander off center, your quality suffers.  Use durable media.  Extract dust.  Make up media in frequent, small amounts.  Consider automation, where gun angle, distance, pressure, and dwell time can be controlled – and you will be blasting fast and lean. 

6. Dust problems are a huge issue, often overlooked – and commonly found with cheap or undersized dust collection equipment.  Especially worrisome are blast machines that positively-pressurize their dust collector systems – where a small leak can send a continuous (but fine) jet of dust into the shop.  Ambient dust can cause failure of sensitive electronics, breathing problems for personnel, and even explosive environments.  Solutions run the gamut from properly equipped, self-cleaning dust collectors, reclaimers that extract dust from the media, to substituting wet slurry blast equipment for dry blast.  Truly industrial vacuums help with housekeeping and are much better at handling abrasives than your typical Shop Vac. 

7. Material Handling and Ergonomics.  Sure, the part will fit inside the cabinet.  But I have seen too many cases where the operator has a hard time reaching all areas of the part that needs to be blasted.  What is called for is figuring out how the operator should interface with the workpiece – and then “build the cabinet” so as not to get into the way!  Sometimes this means a lazy susan.  Or a height extension and operator platform.  Other times it can involve a secondary operator workstation, or an iris to pass the part through the machine.  And at other times, nothing will substitute for a walk-in blast room where the operator suits up.  We build special ergonomic cabinets, automated systems, basket blasters, and robotic blasters, too.  Don’t forget to focus on the optimal nozzle for your project.  Customize the system to your needs.

8. Logistics:  I can quickly find most blasting equipment – it’s located as far from the office as possible.  That is because poorly maintained, inexpensive blasting equipment is “better out of sight and mind” – keeping the mess at bay.  But with the right selection and preventive maintenance, you can now locate blasting equipment where it is needed most.  And that can be inside the workcell for rapid processing and lean manufacturing.  Keep supplies like abrasive there, too.  Incorporate abrasive make-up systems for consistent finishes, and other niceties that you may soon find to be essential to productive, clean blasting. 

9. Utilities:  Start at the beginning.  Figure out the production rate that is required and then determine a nozzle size and style that uses your labor efficiently.  Don’t forget to size your air supply properly.  Quick disconnect fittings on the air supply line are almost always a bad idea, but on the other hand, having an air receiver tank near the blast cabinet is never a bad idea.  Air needs to be clean, dry and oil free.  Your utility may help pay for an efficient Variable Frequency Drive for your central dust collector’s blower – and you will reap those energy savings as long as you run the process.  Bonus:  the VFD can save on abrasive cost, improve process finishes, and help lower noise levels in the shop!

10. Training and ongoing support.  Let’s face it, blasting work is often seen as an entry level position.  But considering that surface prep can be the cornerstone to a quality finish, we often see a mismatch between operation and output.  That’s where ongoing training is important.  Working within the framework of a loyal partnership, a good local distributor can help ensure that each new operator is tuned into the process.  And preventive maintenance contracted to the equipment supplier ensures productive equipment and well trained maintenance personnel. 

 

You can avoid a lot of blasting problems by working with an experienced, knowledgeable distributor with a strong customer support and education program.  Dawson-Macdonald has been servicing local manufacturing concerns since the 1920’s.  We are blasting specialists and offer the expertise that makes a difference to your operations and bottom line.  DM stocks over 200,000 pounds of blasting abrasives – and all common service parts – in our centrally located warehouse.  Unlike other suppliers, we employ full time service technicians that have  decades of hands-on experience to quickly resolve whatever issue arises with your blasting or dust collection operations.  Ask for an onsite evaluation, or visit our blast lab to see how we can improve your operations.  Don’t hesitate to contact me to help you to make your blasting operation lean and clean!

 

© Mark Hanna and BlastPrep, 2017