Walnut Shell in a Wheel Shot Blaster?

When I first got the request from my customer, I was like you want to do what now? As I had never heard of it being in a wheel blaster, air blast sure, but standing up against the power of a wheel throw? Let's dive it... does it work?

I have one customer who is using it a Table Blaster application and loves it. Although I tried to get them to test some parts in a more traditional blast, they insisted on their Walnut Shell.

Yes, walnut shell can be used in wheel blast machines, but with certain limitations and considerations due to its softer, organic nature. Walnut shells are an abrasive commonly used for more delicate cleaning applications, like removing coatings, carbon deposits, and surface contaminants without damaging the substrate material. However, since walnut shells are lightweight and less dense than traditional blast media like steel shot or grit, they can be challenging to use in wheel blast machines, which are typically designed for harder, heavier media. Here are a few points to keep in mind:

• Machine Suitability: Standard wheel blast machines are typically designed to handle metallic abrasives and may need modifications to effectively use walnut shells. The blast wheel speed and power might be too high for such light media, leading to inefficient blasting.
• Adjustments and Modifications: To make it work, the machine settings, like wheel speed and feed rates, may need adjustments. Lowering the blast wheel speed can help prevent walnut shell particles from breaking down too quickly. A VFD (variable speed drive) can come in handy to dial in the right desired impact.
• Applications: Walnut shells are best for applications where a gentle, non-destructive blast is needed, like cleaning turbine blades, engine parts, or molds. It’s less ideal for situations requiring heavy-duty rust or scale removal.
• Wear and Tear: Walnut shells will have a different wear effect on the machine than steel or aluminum oxide. Ensure the machine is designed or adapted to handle organic media, as it may require more frequent cleaning to prevent clogging.

So, while feasible, it's often recommended to use walnut shells in air blast machines, where you have finer control over blast pressure and application, rather than traditional wheel blast setups unless specifically adapted.

When should you reach for Walnut Shell, in what application does this benefit you? The proper media is just as important as the proper machine choice.

Applications that require gentle cleaning without damaging the underlying surface. Here are some advantages:

1. Non-Abrasive Cleaning: Walnut shells are softer than traditional media like steel shot or aluminum oxide, making them ideal for cleaning and stripping delicate surfaces without scratching, etching, or warping. They’re often used on softer metals, wood, fiberglass, and even plastic.
2. Environmentally Friendly: As an organic, biodegradable material, walnut shells are more environmentally friendly than synthetic or metallic abrasives. They generate less harmful dust and can often be disposed of or recycled more easily.
3. Preservation of Surface Integrity: Because walnut shells are relatively soft, they remove coatings, carbon, or dirt without damaging the substrate. This is ideal for applications like engine part cleaning, mold removal, and aerospace or automotive restoration, where preserving fine tolerances is critical.
4. Cost-Effectiveness: Walnut shells can be a cost-effective solution, especially in applications where reusing the media isn't a priority. Although they break down faster than metallic abrasives, their lower cost and suitability for single-use applications can make them economical in certain industries.
5. Reduces Health Hazards: Unlike media that may contain silica or create hazardous dust, walnut shells produce minimal dust with low toxicity. This reduces health risks for operators, especially if a good dust collection system is in place.
6. Surface Preparation for Coating or Bonding: Walnut shell blasting can create a slightly textured surface that is still smooth enough for coatings or bonding. This slight profile may improve adhesion without removing too much material.
7. Versatility: Walnut shell media can be used across a wide range of surfaces and materials without the need for extensive preparation or cleanup, making it adaptable for different industries and surfaces.

These qualities make walnut shells ideal for applications like mold cleaning, engine restoration, turbine blade cleaning, and restoration of antique items where preserving the material's original quality is essential. It effectively removes rust, carbon, paint, and grease without damaging softer materials. This technique preserves the surface integrity, making it suitable for soft metals like aluminum, as well as other delicate materials such as fiberglass, plastic, and wood.

If you are needing help with your blasting whether it is exploring new media options or designing a machine to fit your needs, the LS team has seen just about all it in our 47 years. Let me help guide you on the pros and cons of your choice and get you into the process that works best to meet your desired outcomes.

Sales Manager - Melissa Gibson (Palmer)

[email protected]

316-670-6283