Tag Archives: Blast Media

wet blasting technology, part 4 – typical wet blasting applications

Wet blasting can do nearly any job that is done with dry shot blasting. The defining differences are that wet blasting does so more gently and without producing dust. In addition, wet blasting can handle a small amount of oil and grease unlike dry blasting.

At Rosler, we have more than 80 years’ experience in surface finishing. While wet blasting has gained popularity recently, we’ve used this technique to provide precise, repeatable results to a number of industries over the years.

Typical Applications

With proper testing and process parameters, wet blasting can achieve numerous surface finishing goals.

Cleaning

Fastener with heat discoloration before and after wet blasting.
A fastener with heat discoloration before versus after wet blasting.

Depending on the work piece’s starting condition and successive finishing steps, rust, scale, oxidation, road grime, grease, and oil may need to be removed. Wet blasting can accomplish a variety of cleaning applications including:

  • Dies and molds such as die castings and tire and glass molds.
  • Automotive rebuilds such as engines, transmissions, brakes, etc.
  • Investment castings such as boat propellers, pump impellers, housings, valve bodies, etc.
  • Aircraft engine rebuilds.
  • Various components before inspection or secondary processing.

Burr Removal

Hydraulic components before and after wet blasting.
Hydraulic components before and after wet blasting.

Work pieces with flashings and burrs must undergo deburring and deflashing. For example, firearm components require burr removal after drilling, milling, and turning. Drill bits and milling tools also require burr removal.

Descaling

Despite the newest heat treatment processes, discoloration, oxidation, scale, and hard residues are found on cast and forged products as a result of manufacturing and environmental influences. Modern production methods, control and testing processes, and an uninterrupted continual processing of the cast and forged parts requires clean, light work piece surfaces.

Surface Texturing

Creating a somewhat rougher surface finish is a key step in preparation for painting, coating, and bonding with glue. Ensuring that subsequently applied coatings have a rough enough surface to adhere to improves the quality and life span of a work piece.

Examples of wet blasting applications for surface texturing include:

  • Preparation of automotive parts for rubber coating such as brake and engine seals.
  • Surface preparation to place a corrosion protection coating for screws.
  • Surface preparation to place a primer on airplane components such as rotor blades, stringers, and wing spars.
  • Orthopedic implants in which osseointegration and bone growth around the implant are encouraged. Light profiling of tibia plates, knee femorals, hip stems, and spinal implants helps promote this bone growth.

Stripping of Paint and Coatings

Reconditioning engine components with wet blasting.

Wet blasting is ideal for stripping of paint and coatings from delicate work pieces. Processing of mineral-based construction materials such as concrete or sandstone, glass, textiles, and wood is possible with Rosler machines as well as the finishing of plastics and metals.

Cosmetic Finishing

Wet blasting removes machining lines from aluminum gun bodies as shown in these before and after examples.
Wet blasting removes machining lines from aluminum gun bodies as shown in these before and after examples.

Wet blasting serves as an excellent method of applying a uniform, matte finish on work pieces. This finish can take various forms, including:

  • Creating a pre-polish finish smoother than what can be achieved with dry blasting.
  • Applying a non-glare, matte finish such as the finish required for surgical instruments.
  • Masking machining lines on a variety of parts like tibia implants or aluminum gun bodies.

Shot Peening

Landing gear includes many wet blasted components.

Shot peening is a process specially developed to improve the properties of components which are exposed to changing strains. For safety reasons, shot peening is also now absolutely necessary in the aviation and space industries. Shot peening is also essential in all industries requiring long lives for components including the automotive sector.

Wet blasting applications for shot peening are mainly used in conjunction with Almen strip N for glass beads, ceramic beads, and stainless steel shot.

Additive Manufacturing Post Processing

Additive manufactured components before and after wet blasting.
Additively manufactured components before and after wet blasting.

Wet blasting is an essential technology for various post processing tasks, specifically additive manufacturing. Wet blasting cleans the 3D printed components by removing residual powder and significantly reduces their initial high surface roughness. It is capable of de-powdering and providing general surface cleaning and initial surface smoothing from Ra = 1,000 micro inches down to Ra = 40-60 micro inches (25 µm to 1–1.5 µm).

On metal AM parts the loosely sintered grains on corners are effectively removed. The wet process eliminates the worry about residual powder containment or sparking during the blasting process.

De-contamination of nuclear power plant components

Manual wet blast cabinets allows for same removal of contaminants.

Removal of small, radioactive fragments from the component surface in nuclear power plants can also be achieved through wet blasting. The process decontaminates the components to a point where they can be declassified as radioactive. Special consideration regarding the water treatment are required to meet the requirements for this application.

The Rosler Way

With a trusted partner such as Rosler, you don’t need to worry about the ins and outs of an application. Contact us to discuss your wet blasting needs and challenges and we will deliver a solution. We’ll even demonstrate results with FREE sample processing in one of our global test centers. That’s the Rosler Way.

The complete Wet Blasting Technology Series includes:

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Wet Blasting Technology, Part 3 – Technical Features, Slurry Control Achieve Precise Finishing

Numerous technical features combine to make wet blasting an effective method of surface finishing.

When expertly combined by an experienced finishing expert such as Rosler, this method can achieve precise and repeatable results on a variety of work pieces from a wide range of industries.

A general understanding of the essential technical elements of a wet blasting machine will help you select a machine for your specific needs as well as prolonging the efficiency and life of existing wet blasting equipment.

Continue reading Wet Blasting Technology, Part 3 – Technical Features, Slurry Control Achieve Precise Finishing

Structural Steel FAQ, Part 6 – Blast Media’s Influence on the Steel Surface Profile

The surface profile created by shot blasting depends entirely on the blast media and the way it is handled. The right media selection and equipment operating parameters are critical for the surface quality of structural steel components being prepared for paint coating. While mineral abrasives play a role for certain air blast applications, the lion’s share of industrial surface preparation is done in highly mechanized turbine blast machines utilizing steel media.

turbine screenshot
Media being thrown by a blast turbine.

Rosler Metal Finishing has decades of experience in the turbine blasting field. Through the years, we’ve used and evaluated all kinds of media and resulting roughness or lack thereof. This installment of our Structural Steel FAQ series will answer:

What influence does metallic blast media have on the surface profile
of structural steel?

Types and Shape

Steel shot and grit differ in shape, appearance, and profile results.

Shot has a spherical shape similar to small pellets and creates a relatively smooth, more homogeneous surface profile compared to steel grit.

Continue reading Structural Steel FAQ, Part 6 – Blast Media’s Influence on the Steel Surface Profile

Structural Steel FAQ, Part 2 – Methods of Surface Preparation

Structural steel is a widely used material in a variety of industries due to its strength and durability. Our last post in the Structural Steel FAQ series established why this material must be prepared – namely to preserve its strength and longevity. This post will describe the type of surface preparation required before shot blasting structural steel.shipbuilding2938x450

In order to stand up to the harsh demands of the construction, shipbuilding, and heavy equipment industries, the most appropriate type of surface preparation must be undertaken to ensure the best shot blasting results possible.

As always, consult a surface finishing expert such as Rosler Metal Finishing with to discuss your specific components, their condition, and the desired outcome for your structural steel applications.

We turn to another FAQ about structural steel: What type of surface preparation is required prior to shot blasting?

The answer depends on the condition of the component…

Read more about structural steel surface preperation

Shot Blasting 101

Shot blasting is a specialized surface finishing process where small metal (or mineral) pellets, called blast media, are thrown onto the surface of a work piece at incredibly high speeds, ranging from 200-800 feet per second.  The impact on the work pieces from this process is what produces the desired surface finishing effect.

Shot blasting can help achieve surface cleaning, surface preparation, descaling, deburring, deflashing, and shot peening.

The process components of a shot blasting system include a shot blast machine, raw and finished work pieces, blast media, dust, and other byproducts.

The two most common types of shot blast machines are turbine blasting and air blasting.

Continue reading Shot Blasting 101

Blast Media – Considerations when choosing

Important factors that should be considered in the selection of any blast media for a particular application is the material and chemical composition, hardness, density, shape, screen size, and, last but not least, the hardness of the component to be blasted.

Component image

The term ‘media’ as used in mechanical surface finishing refers to the free flow abrasive or non-abrasive type of media which carries out the process required on the component.

So, what can be considered and used as a blast media?

Anything! That can be projected through a blasting system.

Media Characteristics to be considered include:

Continue reading Blast Media – Considerations when choosing

Shot Peening – Blasting for Longer Component Life

High speed and highly controlled, the process of shot peening has many similarities to the aerospace, automotive, and aviation components it is used on. The machines require absolute precision and reproducibility much like the components they are preparing for long life and changing loads.

Shot peening is a special shot blasting process in which spherical blast media is thrown at the surface of metallic work pieces. The impact energy of the pellets “cold forms” the upper layers of the metal similar to hammering and forging processes.

More on shot peening for longer component life

Blast Medias – Considerations : Choice And Use

Important factors that should be considered in the selection of any blast media for a particular application is the material and chemical composition, its hardness, its density, its shape, screen size and last but not least, the hardness of the component to be blasted.

Component image

Continue reading Blast Medias – Considerations : Choice And Use