Abrasive Blasting Technical Tips

/Abrasive Blasting Technical Tips
Abrasive Blasting Technical Tips2019-09-04T11:02:58-04:00

Abrasive Blasting Technical Tips

Customers often have a variety of technical and application questions about the proper selection, performance, and use of BARTON abrasives.

In addition to the information found elsewhere on this website, this section is provided by various experts at BARTON regarding topics that have come up frequently in conversation with customers. We hope you find the information helpful. Of course, if you have a question that’s not addressed in this section, don’t hesitate to call 800-741-7756. BARTON customer service professionals are always ready to answer your questions.

Achieving maximum blasting performance with BARTON garnet abrasives

Joe Morris, National Sales Manager

What are some of the best practices to help ensure maximum blasting performance?2019-04-02T09:47:06-04:00

Abrasive blasting is a complex process with numerous variables that impact performance. Every blasting application is unique. Proper planning, close monitoring, occasional adjustments, and recycling as appropriate are necessary to create a safe, efficient, and environmentally sound blasting operation.

These abrasive blasting guidelines will help operators achieve maximum performance from BARTON’s blast-media garnet abrasives.

Clean Blast Pot

Remove all foreign materials or other blasting abrasives from inside the pot and make sure the filter is clean. Contaminants that remain from previous use make proper abrasive metering difficult and increase dust generation.

Air Supply

Use clean, dry air (use aftercooler/dryer as needed) with an air pressure range of 90-110 psi at the nozzle. Higher air pressure yields greater productivity, all things being equal, but it also increases particle breakdown. When recycling, BARTON recommends 95 psi at the nozzle. Pressures above 100 psi at the nozzle help ensure optimum abrasive efficiency in the form of faster cutting and lower abrasive consumption. When recycling, operator will need to determine optimal settings to balance cutting speed with recycled yield.

Abrasive Metering

Very little garnet is required to produce a clean, uniform finish compared to other blast media. In general, you will use only about half as much garnet as compared to coal slag, provided you are using the correct grade of garnet (See grade selection guidelines below). To set the proper abrasive metering, close the metering valve, then open it slowly while blasting to introduce abrasive to the air stream until you reach the point where the optimal cut is achieved.

For new steel applications and to remove coatings under 5 mils, one indication of a proper abrasive metering is a “blue flame” at the nozzle. A coating that is thicker and more difficult to remove requires more abrasive to be metered into the air stream to maintain fast cutting.

Note: Running the abrasive too lean will reduce cutting speed. Running the abrasive too rich will waste abrasive, increase dust generation, etc.

Nozzles, Couplings and Whips

A venturi-type nozzle will yield maximum performance. A long-bore #7 or #8 is suitable for most applications. Use the largest nozzle possible given application and sufficient air pressure/volume. Replace nozzles once they become 1.5 sizes larger than the original orifice.

Determining the correct garnet abrasive grade for surface preparation

Joe Morris, National Sales Manager

What are the guidelines for deciding the proper blasting abrasive grade to use?2019-04-02T09:47:06-04:00

The blast media and grade required for a particular application is determined primarily by the profile specified and the thickness and type of coating/contaminant to be removed. Always conduct testing on the surface to be cleaned to determine the best grade, given the application-specific performance required. As a rule, use the finest grade that will produce the needed profile and remove the coating quickly.

To produce a 3.5 – 4.5 mil profile on steel (SSPC-AB 1, Grade 4)
Recommended blast media: 36 mesh – ADIRONDACK 36 CG
Frequently used to remove thick coatings, marine fouling (20-50 mils) and rust

To produce a 2.5 – 4.0 mil profile on steel (SSPC -AB 1 Grade 3 and Grade 4)
Recommended blast media: 30/60 mesh – ADIRONDACK 30/60 CG
Frequently used to remove heavy coatings (up to 40 mils) and rust while controlling profile

To produce a 2.5 – 3.5 mil profile on steel (SSPC-AB 1, Grade 3 and Grade 4)
Recommended blast media: 30/60 mesh – ALLTEK 30/60 Plus
Frequently used on new steel and maintenance work on coatings up to 20 mils

To produce a 2.0 – 2.8 mil profile on steel (SSPC-AB 1, Grade 3)
Recommended blast media: 80 mesh – ALLTEK 80 HPA
Frequently used on aluminum and other more sensitive substrates

To produce a 2.0 – 2.5 mil profile on steel (SSPC-AB 1, Grade 3)
Recommended blast media: 80 mesh – FUSION 80
Frequently used for single-pass applications on new steel where consistent profile is critical

About the Author

Joe Morris
National Sales Manager

Joe Morris National Sales Manager provides Abrasive Blasting Technical Tips to help you get the best resultsJoe Morris has been with BARTON International since 2006. Joe has more than 18 years’ experience with abrasive blasting and coating application methods and has led the efforts to expand the use of garnet for surface preparation. In addition to heading Barton’s national sales team, Joe manages the company’s blast media division.