Top 10 Mistakes New Blasters Make

Practical Lessons from the Field

Blasting is one of the most powerful and effective tools used in mining, construction, quarrying, and avalanche control. However, it is also an activity that requires training, planning, and strict adherence to safety procedures.

New blasters often make mistakes that can lead to poor fragmentation, excessive vibration, flyrock, regulatory violations, or serious safety hazards.

Below are the 10 most common mistakes new blasters make and how they can be avoided.

1. Poor Blast Design

Many new blasters underestimate the importance of proper blast design.

A blast should never be based on guesswork. Key parameters such as burden, spacing, bench height, and hole diameter must be calculated correctly.

Poor blast design often results in:

• Oversized boulders

• Excessive ground vibration

• Incomplete rock breakage

• Flyrock hazards

Professional blasters always start with a clear design and calculations before drilling begins.

2. Incorrect Burden and Spacing

Burden and spacing control how the explosive energy is distributed in the rock.

If burden is too large, the blast may fail to break the rock properly.

If burden is too small, the blast may produce flyrock or dangerous airblast.

Proper burden and spacing should be determined using:

• Hole diameter

• Rock type

• Explosive type

• Bench height

3. Poor Stemming Practices

Stemming is one of the most overlooked parts of blasting.

Stemming helps confine the explosive energy within the hole, allowing it to break rock rather than escape through the collar.

Common mistakes include:

• Using incorrect stemming material

• Insufficient stemming length

• Using drill cuttings instead of crushed rock

Good stemming significantly improves blast efficiency and safety.

4. Incorrect Primer Placement

Primer placement controls how the detonation wave travels through the explosive column.

Typical mistakes include:

• Placing the primer too high in the hole

• Using multiple primers incorrectly

• Poor coupling of the detonator

Most production blasts use bottom priming, which allows the detonation wave to travel upward through the explosive column.

5. Using the Wrong Explosive for the Job

Different blasting situations require different explosives.

Examples:

• ANFO for dry holes in hard rock

• Emulsion explosives for wet conditions

• Water gels for special applications

Using the wrong explosive can result in:

• Poor detonation

• Misfires

• Reduced energy output

6. Ignoring Ground Conditions

Every rock mass behaves differently.

New blasters often fail to consider:

• Rock joints

• Bedding planes

• Water in boreholes

• Variable geology

A blast design must always be adjusted based on actual ground conditions.

7. Improper Delay Timing

Delay timing controls how the rock moves during a blast.

Poor timing can lead to:

• Increased vibration

• Poor fragmentation

• Face cutoffs

• Airblast problems

Modern blasts use millisecond delays to control rock movement and improve breakage.

8. Poor Powder Factor Control

Powder factor describes the amount of explosive used to break a given volume of rock.

Using too much explosive can cause:

• Flyrock

• Excessive vibration

• Overbreak

Using too little explosive can cause:

• Poor fragmentation

• Large boulders

• Secondary blasting

A properly designed powder factor is essential for efficient blasting.

9. Inadequate Safety Procedures

Blasting operations require strict safety protocols.

Common mistakes include:

• Poor blast area security

• Inadequate warning signals

• Failure to account for personnel

• Improper misfire procedures

Safety must always be the top priority in blasting operations.

10. Lack of Training

Perhaps the most significant mistake is attempting blasting without proper training and education.

Blasting involves:

• Federal and state regulations

• Explosive handling procedures

• Blast design calculations

• Environmental and safety considerations

Professional training helps new blasters understand the science and engineering behind safe blasting practices.

Learn Safe Blasting with PETS

The Practical Explosives Training School (PETS) provides professional education for blasters, engineers, and safety professionals working with explosives.

Our courses cover:

• Explosives fundamentals

• Blast design calculations

• Safety and regulations

• Field case studies

💥 Blast smarter. 💥Break rock better. 💥Train with the professionals at PETS. 💥

Visit:  petrexplosivesgroup.com