Pros and Cons of Wet Blasting

Wet blasting also known as Vapor blasting has grown a lot in popularity recently.  It is a great solution for certain sandblast applications and like any application has its pros and cons. Our goal is to cover the benefits and drawbacks of wet blasting so that you can determine if it might be a good fit for your sandblasting needs.

Wet Blasting Pros

• One of the biggest advantages to wet blasting is the potential to reduce dust, especially when using a sandblast media that breaks down easily like coal slag.
• An additional advantage to wet blasting is being able to wash the surface with water in a single step.  This can be beneficial if using air alone to blast the surface of a product’s surface off is not sufficient enough to properly clean the surface of any remaining blast media prior to coating application.
• Can sometimes help reduce media use – The amount of media you use will vary based on a lot of factors with any blast application. Typically the size of the blast nozzle will be the biggest factor in determining the amount of sandblast media you consume. With a wet blasting system you will be adding water into the media stream which can help to reduce the amount of media you use depending on the substrate being blasted and how strong the contaminant is adhering to the surface.
• Less Senstivity to Outside Conditions – This benefit depends on the style of wet blaster you are using. For example if you are using a wet blaster that has water mixed in with media, then your blast outfit will not be as effected by humidity because their is water already in your blast media and you will be using a rust inhibitor.

Wet Blasting Cons

• Wet Blasting will be more expensive to start – Wet blasting will require both a sandblast pot as well as a water injection system. Depending on if you upgrade an existing blast pot or choose a fully integrated system you can spend anywhere from a few thousand dollars up to almost double or more the price of a regular blast pot.
• It can result in flash rusting (leaving less time to apply a protective coating) –  Whenever you sandblast you remove the mill scale, rust or coating from a products surface. Regardless if you wet or dry blast the surface will begin rusting again if a protective coating is not applied. However, with wet blasting you will have less time to wait until the surface starts corroding again and will have to use a rust inhibitor to be able to use the equipment. This is because water accelerates corrosion, the rust inhibitor will help slow the process but even with the inhibitor a wet blasted product will have less time available compared to a dry blasted product before corrosion starts.
• Containment of blast media can be challenging – Depending on what you are blasting and what you are blasting with you may need to be able to retain all residual blast media and byproduct of your blasting. If this is the case you would need to be able to retain the water that is produced from wet blasting, which could be challenging.
• You may not be able to stop blasting for much time – With a dry blast media you can stop blasting for a while to tend to an issue and return to blasting. However, depending on the style wet blaster you have you may not be able to stop blasting for very long. This is particularly applicable if your wet blaster mixes water in the media. If you leave water mixed with media in your blast pot for too long the two will form a hardened mass in the blast pot making for a challenging clean up.

Conclusion

A wet blasting system can be a good option in certain applications. Its greatest benefits are the ability to reduce dust that is created by blasting as well as the potential to provide a cleaner surface while potentially using less media. The greatest downsides with a wet blast system include the higher initial costs, certain application limitations, and difficulties that can happen when trying to contain your blast media. If you wonder whether wet blasting could be an improvement for your application or the right idea for your need we recommend trying a wet blast system with your process. Do you have additional questions, or want to demo a wet blast unit?  Contact us to see if we can help.