Abrasive Blasting 101
Wet blast cabinets have been around for a very long time. Although dry blasting almost made wet cabinets obsolete, more and more applications today require wet blasting because it eliminates the frictional heat that can damage delicate parts and permits iron free blasting. A few wet blasting applications include critical plating and painting, chemically clean part surface, no abrasive impregnation into the part surface, and aircraft part cleaning with the least part surface removal.
If you’re preventing the abrasive from embedding into the part surface, or you need a chemically clean surface for critical plating and painting, or you need to eliminate frictional heat for medical parts and circuit boards you will need a wet blasting cabinet. Applications for semi-conductors and minimal part surface removal used in aircraft remanufacturing and wheel refurbishing also use wet blasting. Here are a few of our favorite FAQs about wet blast cabinets:
Yes, it really does if you value labor costs. Understand that wet blasting has no frictional heat and it’s very slow when compared to dry blasting. If you need 23 percent abrasive suspended in the water to create the fastest wet blasting possible you need an efficient slurry pump. How do you increase the abrasive density? A sealless slurry pump! Remember, you can always lower the percentage of abrasive but cabinets only suspending 9 to 10 percent can never increase slurry percentages.
Pro Tip: A sealless slurry pump, working with a mist collector, can increase abrasive % in suspension and lower maintenance cost as well as create a negative pressure inside the cabinet to allow the large 1/2″ 90 cfm gun usage.
Wet blast cabinets by nature are slower cleaning, normally made of stainless steel, and require a sealless slurry pump if you want higher slurry percentages with faster cleaning times. These are costly items increasing the machine cost.
Stainless steel construction is one major factor increasing the cost of wet blasting cabinets but not the only reason. Wet cabinets are available in mild steel, but the soon rust into (rust blasting cabinets) as the cabinet disintegrates.
To maximize cleaning speed, you want the highest percentage of abrasives in suspension possible and the largest possible gun size. Particle density is the answer to the slow speed of wet blasting and helps to lower the cost of labor. This is why you want to add a slurry pump and the largest possible gun size, 1/2” nozzle and 1/4″ airjet blasting at 90 to 100 psi to your machine.
ProTip: You can lower the percentage of abrasive inside any wet blasting cabinet but you can’t increase the abrasive percentage inside a cabinet with weak agitation and maximum abrasive percentages listed at only 9 to 10%.
In the 50s you could find Air Agitation to carry the abrasive into suspension if the abrasive to be used was very fine. You could also find slurry pump agitation using the old type of pump that included packing gland to prevent the vertical pump shaft from leaking on the floor. The problem was you always needed to tighten the packing gland to prevent leaking; this would damage the shaft resulting in costly maintenance. Keeping abrasive in suspension for long enough to allow the abrasive gun to capture and deliver to the part could be a problem with Air Agitation or Paddle Wheel Suspension. By the time the cabinet was large enough to house a typical part, the abrasive was settling out of suspension. In the early days almost all wet machines were made using mild steel because today’s fabrication tools didn’t exist for stainless steel construction.
Today you can find the stainless steel constructed wet blasting cabinets using sealless slurry pumps. With the addition of new wet blasting applications comes more companies offering wet blasting cabinets – some that have never manufactured wet blast cabinets before and some not meeting code!
If you are thinking about wet blasting today always choose your cabinet based on your application and or Daily Duty Cycle. Do you want an inexpensive mild steel cabinet or fiberglass cabinet using abrasive percentage suspension of 10% or less? Or do you want the quality and speed of a stainless steel cabinet with a sealless slurry pump? When you are using a Sealless Slurry Pump and you require large abrasive media it’s about fast recirculation to keep the abrasive in suspension, compressed air and paddle pumps are a poor substitute. Standard Sealless Slurry Pumps can naturally be larger to handle larger abrasive and faster circulation.
ProTip: Always ask what the maximum abrasive percentage is of any wet blasting cabinet and the maximum abrasive mesh size that you can use along with maximum blasting pressure and gun cfm size. This will tell you about cleaning speed and value for dollar. If you compare cleaning speed and machine cost, next calculate the labor per year against part production or hourly usage. You can quickly see savings of more than $100,000.00 per year based on labor savings for one blasting cabinet. Never accept a limited gun size, limited abrasive mesh size or limited blasting pressure for a few dollars in savings.
Sure you can! Yesterday it was much harder, but with the new applications today requiring wet blasting you can find many limited application machines. Unfortunately, as with all blasting cabinets, you get what you pay for with wet blasters. If you choose to cut your budget and go for the cheapest option don’t be surprised to find your cabinet rusting after a short time and the fine 220 mesh abrasive soon is contaminated with 36 mesh rust.
Media Blast & Abrasive has been manufacturing sandblasting cabinets since the 1970s. We make more than 180 standard models and sizes of abrasive blast cabinets including our wet blasting cabinet: the Hurricane. In addition to a comprehensive list of included features, we offer more than 80 optional features for increased productivity, durability, and operator safety. If you’re not sure whether a wet blast cabinet is the right fit for your needs, give us a call or visit our Buying Guide.