How to select the Best Abrasive for Surface Preparation in 2020

Not all Blast Abrasives are created equal.  Selecting the optimum Abrasive Media for Abrasive Blasting Surface Preparation is the most important decision to be made to achieve the lowest overall cost per square foot.

Choosing the best (lowest cost per square foot) abrasive for a project involves answering the following questions:

• Which Abrasive(s) will allow for the fastest Production Rates? Fewest man hours.
• Which of the Abrasive(s) exhibits the lowest Consumption Rates? Least tonnage purchased.
• How important is greater visibility (low Dust Levels) for this project? For example, interior of tanks or enclosed areas will require the absolute lowest Dust Levels.
• Is the steel substrate painted – and if so, what is the condition? Or is it new, uncoated steel?
• Given the delivered price per ton of each Abrasive per project, which Abrasive(s) has the lowest overall price per square foot factoring in the Abrasive characteristics from above?
• Cost per ton is not the most relevant parameter in order to determine lowest cost per square foot.

Let’s review the more popular available Abrasives.

Iron Silicate (Copper Slag)

Just like Abrasives in general, not all Iron Silicates (Copper Slags) are created equal.  TCR Blast Abrasives markets only the High-Performance varieties of Iron Silicate – that is, Low Dust, Low Consumption Rate and high Production Rates.  Depending on the specific project and location, Iron Silicate is almost always the top 1 or 2 Abrasives candidates in terms of overall cost per square foot based on the following:

• Low Dust Levels
• Very low Consumption Rates
• Excellent Production Rates
• Works on both new steel and coated steel
• Recyclable 2 to 3 times
• Can be used in Slurry Blast systems
• Among the lowest in cost per ton of all High-Performance Abrasives
• Very low Cost per square foot

Aluminum Oxide Abrasive

Aluminum Oxide is processed from the Bauxite ore.  As a result of having to “produce” the Aluminum Oxide Abrasive, impurities (e.g., free silica, trace heavy metals, etc.) are at very low concentrations – if even detected.  The great advantage of AlOx is the MOH Hardness of 8 to 8.5 – among the very hardest of Abrasives widely available.  AlOx is available in brown, black and white colors – each sourced from different production facilities throughout the US.  Higher cost is the disadvantage of AlOx.  To summarize, the AlOx properties are:

• Very, very low Dust Levels
• Very low Consumption Rates
• Very good Production Rates
• Works on both new steel and coated steel
• Recyclable 4 to 6 times
• Among the highest in cost per ton of all High-Performance Abrasives
• Medium to High Cost per square foot compared to other High-Performance Abrasives

Garnet Abrasive

In terms of performance and pricing within the High-Performance Abrasive arena, Garnet resides between AlOx and Iron Silicate Copper Slag.  Both pricing and performance of Garnet are greater than Iron Silicate Copper Slag – but less the AlOx.  Garnet is however the Abrasive of choice in the Waterjet Cutting industry – in conjunction with Ultra-High Pressure (40,000 to 60,000 psi) Waterjets that precisely cut up to 2” plate steel or other materials.  Pink to gray-pink in color, Garnet is also used in dry abrasive blasting operations were low dust, low Consumption Rate and high Production Rates with moderate costs are important.  Garnet is derived from beach sands (alluvial – or sub-angular – Garnet) – or the mineral is mined out of the ground in Garnet rich veins (Hard-Rock Garnet – more angular than alluvial).  To summarize Garnet properties:

• Very low Dust Levels
• Very low Consumption Rates
• Excellent Production Rates
• Works on both new steel and coated steel
• Recyclable 3 to 4 times
• Can be used in Slurry Blast systems
• Moderate cost per ton in the High-Performance Abrasive market
• Moderate Cost per square foot

Recycled Crushed Glass

Recycled Crush Glass is made from processing of post-consumer glass products such as glass bottles, jars and other glass containers & objects.  It is used extensively in Slurry Blast systems whereby water is mixed with the Crushed Glass Abrasive (along with a Flash Rust Inhibitor) and the substrate is “wet” blasted to remove old coatings, corrosion, or other contaminates.  Crush Glass has a light off-white color and used by many Abrasive Blasters because the residue is sometimes left on the ground (inert & innocuous residue).  Very low free silica, very low trace heavy metals both contribute to the clean waste stream when using Crushed Glass.  It is only around 6 MOHS Hardness – and will create some level of dust if used as dry abrasive.  And the low density & relatively low hardness translates to using Crushed Glass in “light” cleaning operations.  Crushed Glass features are:

• Moderate Dust Levels (unless “Wet” Blasting)
• Moderate to good Consumption Rates
• Production Rates similar to coal slag and silica sand
• Works on both new steel and lightly coated steel
• Not Recyclable
• Used extensively in Slurry “Wet” Blast systems
• Low to Moderate cost per ton
• Moderate Cost per square foot

Most Abrasive Blast operations are driven to use the lowest cost per square foot for a particular project.  Factors that have the greatest impact on cost per square foot include:

• Job location – proximity to Abrasive source greatly affects the freight cost
• Consumption Rate – lower Consumption Rate Abrasives means less media purchased
• Production Rate – the quicker an Abrasive prepares the substrate, the lower the Labor Cost. Lower Labor Costs usually has the most direct impact on lowering cost per square foot.
• Lower cost per ton + freight.

If you need assistance is selecting the optimum Abrasive for your Blast Operation, call or email Keith (keith@tcrcoatings.com) or Dan (dan@tcrcoatings.com) at TCR Blast Abrasives to work through the process.  We will demonstrate how to lower the overall cost per square foot for the Abrasive Blast Operation.