As a seasoned sandblasting professional, I can confidently tell you that one of the most commonly overlooked thing while sandblasting is the proper management of static electricity.
While many may think that a simple static shock is nothing to worry about, the truth is that the type of static electricity generated by sandblast cabinets can be much more dangerous than you may realize..
In this article I’ll go in depth on causes of shock in sandblasting cabinet and how to reduce it quick and easy –
Why is my sandblast cabinet shocking me?
The main reason your getting shocked by your blast cabinet is the process of the nature of the sandblasting process itself. As you are shooting abrasive particles at high speeds, they are creating friction against the walls of the cabinet and other equipment such as- gun and nozzles, leading to the accumulation of static charges. Charges mostly accumulate in your blast cabinet. These charges then discharge as a shock if you come in contact with the equipment, potentially causing you injury or damage.
The level of static electricity build-up in your cabinet can vary greatly depending on a many factors. Such as –
1. Humidity level in your workshop
The moisture content in the air of your workplace greatly affects the level of static charge that can build up on the surface of the abrasive particles and the equipment itself.
When the humidity level is low, the air is dry, and there is little moisture to neutralize the static charges. This can lead to a significant increase in the risk of static discharge and electrical shocks.
On the other hand, when the humidity level is high, there is more moisture in the air that act as a conductor, reducing the build-up of static charge.
This is why you may notice that in more humid climates, static shocks are less frequent compared to dryer areas.
2. Type of abrasive media you are using
No matter which abrasive media you use they tend to create static charge. But, abrasive media such as Glass beads or plastics create more charges compared to aluminium oxide or silicon carbide.
Even the type of clothes you are wearing while sandblasting can affect the level of static electricity build up.
How to Reduce Static Shock from Sandblast Cabinets?
To reduce static shock from sandblast cabinets, there are several steps you can take:
1. Properly ground your cabinet:
To avoid getting zapped, grounding the cabinet is the most fundamental thing you can do. You can use a grounding wire to attach the cabinet to a grounded outlet, or you can use a grounding strap to connect the cabinet to a nearby metal object. For example, you can connect your gun to the cabinet body through a grounding wire.
You should ensure that the wire or strap is securely attached to the cabinet and that the grounding point is a “true earth ground” to help the dissipation of static electricity. This will help dissipate any static charges that build up in the cabinet, reducing the likelihood of a static shock.
Grounding the cabinet ensures that any static charges that accumulate during the blasting process are safely dissipated through the grounding point. However, it is important to note that grounding alone may not be sufficient to eliminate static buildup entirely.
To maximize safety, a combination of measures should be employed, including using conductive blast media, increasing humidity, and utilizing anti-static products to mitigate the risk of static buildup and prevent static shocks.
2. Use anti static tools:
You can use various types of anti-static tools to make yourself safe from static shock. Such as:
- anti static gun-nozzles
- grounding wrist straps,
- and anti-static mats.
Here’s a value for money static sandblaster grounding kit.
Grounding wrist straps connect works by connecting you to a ground point, which allows any static charges to dissipate through the ground rather than building up on your body.
Similarly, anti-static mats are placed on the floor of the sandblast cabinet and work by dissipating any static charges that build up on the surface.
3. Use Conductive Blast Media:
Switching to a conductive blast media, such as aluminum oxide or steel grit, can also help reduce static shock in the sandblast cabinet. Conductive media helps to dissipate static charges as they build up, preventing them from accumulating and causing a shock.
Conductive blast media is made from materials that have high electrical conductivity and can conduct electricity away from the surface of the media.
When the conductive blast media is used, it creates a conductive path between the surface being blasted and the sandblast cabinet, which allows any static charge to dissipate through the conductive path rather than building up in the cabinet. This reduces the risk of static shocks and the ignition of flammable materials.
4. Use Humidity control devices:
If you are workplace is in a dry area or it’s a dry day increasing humidity levels is an effective way to reduce static buildup in the sandblast cabinet. You can use a humidifier or add plants to the area to increase the humidity level. Higher humidity levels help dissipate static charges, reducing the likelihood of a static shock.
Avoid standing on insulated mats in front of the sandblast machine as they can prevent the static charge from consistently dissipating.
Does sandblasting create static electricity?
Yes, sandblasting can create static electricity. When the abrasive media particles are blasted against a surface, they can rub against each other and the walls of the sandblasting cabinet, which can generate static charges. These static charges can build up in the sandblasting cabinet and on the surface being blasted, which can increase the risk of static electricity discharges or sparks that can potentially ignite flammable materials.
Why is Static Shock from Sandblast Cabinets Worse on Some Days?
The severity of static shock from sandblast cabinets can vary based on several factors, including humidity levels and the types of materials being blasted. On days with low humidity, the air is drier, which can increase the buildup of static electricity in the sandblast cabinet. Additionally, certain materials, such as plastics, are more prone to developing static charges, which can increase the likelihood of static shock. The buildup of static electricity can also be influenced by the speed and pressure of the blasting process, as higher speeds and pressures can create more friction and generate more static charges.
Can sandblasting cause sparks?
Yes, sandblasting can cause sparks if the blasting media strikes a hard surface, such as metal, at a high velocity. This can create sparks, which can be a fire hazard if they come into contact with flammable materials.
Can static shock start a fire?
In some cases, yes, static shock can start a fire. If a static charge is discharged near a flammable material, it can ignite the material and start a fire. However, this is a rare occurrence and typically only happens when working with highly flammable materials.
Is Static Shock harmful?
Static shock is generally not harmful and is considered a nuisance more than anything else. However, in rare cases, a static shock can be strong enough to cause muscle contractions or startle you, which can lead to an accident or injury.
Can static shock hurt you?
In general, static shock is not strong enough to cause serious harm or injury to you. However, in rare cases, a static shock can be strong enough to startle you, causing you to fall or drop an object, which can lead to injury.
Additionally, if you have certain medical conditions, such as a pacemaker, you should avoid exposure to static electricity, as it can interfere with the function of your device.