FAQ

1What is Shot Peening?
Shot peening is a cold working process used to produce a compressive residual stress layer and modify mechanical properties of metals. It entails impacting a surface with shot (round metallic, glass, or ceramic particles) with force sufficient to create plastic deformation.

It is similar to sandblasting, except that it operates by the mechanism of plasticity rather than abrasion: each particle functions as a ball-peen hammer. In practice, this means that less material is removed by the process, and less dust created.
2What Media are Used for Finishing?
Mineral: Silica sand can be used as a type of mineral abrasive. It tends to break up quickly, creating large quantities of dust, exposing the operator to the potential development of silicosis, a debilitating lung disease. To counter this hazard, silica sand for blasting is often coated with resins to control the dust. Using silica as an abrasive is not allowed in Germany, United Kingdom, Sweden, or Belgium for this reason.

Another common mineral abrasive is garnet. Garnet is more expensive than silica sand, but if used correctly, will offer equivalent production rates while producing less dust and no safety hazards from ingesting the dust. Magnesium sulphate, or kieserite, is often used as an alternative to baking soda.

Agricultural: Typically, crushed nut shells or fruit kernels. These soft abrasives are used to avoid damaging the underlying material such when cleaning brick or stone, removing graffiti, or the removal of coatings from printed circuit boards being repaired.

Synthetic: This category includes corn starch, wheat starch, sodium bicarbonate, and dry ice. These "soft" abrasives are also used to avoid damaging the underlying material such when cleaning brick or stone, removing graffiti, or the removal of coatings from printed circuit boards being repaired. Sodablasting uses baking soda (sodium bicarbonate) which is extremely friable, the micro fragmentation on impact exploding away surface materials without damage to the substrate.

Additional synthetic abrasives include process byproducts (e.g., copper slag, nickel slag, and coal slag), engineered abrasives (e.g., aluminum oxide, silicon carbide or carborundum, glass beads, ceramic shot/grit), and recycled products (e.g., plastic abrasive, glass grit). Metallic: Steel shot, steel grit, stainless steel shot, cut wire, copper shot, aluminum shot, zinc shot.

Many coarser media used in sandblasting often result in energy being given off as sparks or light on impact. The colours and size of the spark or glow varies significantly, with heavy bright orange sparks from steel shot blasting, to a faint blue glow (often invisible in sunlight or brightly lit work areas) from garnet abrasive.
3What Is Exactly Abrasive Blasting?
Abrasive blasting is the operation of forcibly propelling a stream of abrasive material against a surface under high pressure to smooth a rough surface, roughen a smooth surface, shape a surface, or remove surface contaminants. A pressurized fluid, typically air, or a centrifugal wheel is used to propel the blasting material (often called the media). The first abrasive blasting process was patented by Benjamin Chew Tilghman on 18 October 1870.

There are several variants of the process, such as bead blasting, sand blasting, sodablasting, and shot blasting.
4Will Polishing Increase Or Decrease The Value?
Generally when restoring an item back to its original condition the value of an item will remain the same or increase. We have on staff experts that will advise you as to the ideal course of action for your particular item. There are a few instances when we advise against refinishing. Certain items just are not worth refinishing, or they should remain in an untouched state. When these items enter our shop, we give our honest opinion of what should or shouldn’t be polished.
5Is My Job Too Small?
Please note that we do not limit our processes to materials and markets. Over the years we have had the opportunity to serve customers with one piece who walk in off the street as well as large companies with thousands of pieces. We are building our customer relationships, and we are determined to please our new customers. We know how important it is to start off on the right foot as we grow our reputation for quality service.

Our mission has been to provide superior service in the metal polishing industry while consistently exceeding our customers quality and delivery expectations. We have a strong commitment to continual quality improvement and investments in the newest technologies. Superior quality, competitive prices, and rapid turnaround are our measures.
6What is Glass Bead Blasting?
Glass bead blasting is the process of blasting a surface with tiny glass beads at extremely high pressure in order to clean the surface of any external deposits such as paint or rust. Despite the high pressure, the metal is not damaged by the process. In the automotive industry, glass bead blasting is often used to remove paint from a vehicle prior to priming and re-painting, as well as removed rust from a vehicle.
7Ultrasonic Cleaning vs Drum Washing
Both ultrasonic cleaning and drum washing are methods used to clean parts or tools. These two methods differ when it comes to specific usage, as well as delicacy of the clean. This post will detail ultrasonic cleaning versus drum washing and give insights into when each one should be used.

Ultrasonic Cleaning:

Ultrasonic cleaning is an advanced process that uses ultrasound (typically between 20-400 kHz), as well as a liquid cleaning agent to clean fragile products. This is done by placing the product into the cleaning liquid, and then lowering in a transducer. The transducer will then produce ultrasonic waves. These waves will create tiny “voids” or “vacuum bubbles” which then collapse to produce very high pressures - up to 20,000 lbs per square inch. Due to the minute size of the bubbles, the process merely cleans the surface of the product. Higher frequency ultrasound is used to create smaller bubbles, which can clean more complicated products.

Drum (Auger) Washing:

Drum washing is the more traditional approach to part washing. A product is sent through a machine where it is then washed, rinsed, dried, and unloaded. Chemical agents can be used during the cleaning process in order to achieve a higher degree of clean when dealing with impurities such as grease and dirt. Drum washing differs greatly from pressure washing, as parts are cleaned automatically in an enclosed machine, versus a pressure washer which typically has a single spray nozzle, and must be operated manually.
8What is Shot Blasting?
Shot Blasting is a method that is used to clean, polish, and strengthen metal. Shot blasting has become a part of almost every industry that works with metal products and parts on a regular basis. Shot blasting is necessary to prepare metal for surface coats, such as plating, paint, and overlays. Shot blasting is commonly used in the auto industry in both the preparation of new parts, and the restoration of old parts.
9What is Wheel Blasting?
Wheel blasting is a different method of blasting a surface in order to clean a metal product. Instead of using high pressure air to propel beads, a spinning wheel is used. The centrifugal force of the spinning wheel propels beads at an adjustable rate in order to fine tune the abrasiveness of the clean.

A wheel machine is a efficient method of blasting, since the abrasive (typically steel shot, cut wire, pellet, or grit) is recycled throughout the operation.
Obertec Limited 905.625.9955
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