Crushed Glass VS Coal Slag Blast Media

Glass and Coal slag are two popular sandblast medias. Both have their benefits and drawbacks making them best suited for certain blast applications more so than others. In this article will cover crush glass and coal slag, their pros and cons, and which may be best for your blast application.

Crushed Glass- What its capable of

Crushed glass is commonly available in a few different mesh sizes. Crushed glass is commonly used for applications that require removal of a variety of degrees of paint from light to heavy layers of paint. Depending on the mesh size of the crushed glass, pressure, and time spent in a specific area you can achieve mil profiles of 2 – 6 mils.

What are Crushed Glasses Pros

• Better visibility when blasting – Since crushed glass is clear it will not have as dark of a cloud associated with it compared to coal slag
• Less Dust – Crushed glass will fracture like coal slag but will not create as large of a dust cloud. This can be helpful when you are trying to blast in an area where large visible clouds of dust are problematic
• Environmentally friendly – Crushed glass is inert which depending on your location can be safe to use around water; it is always recommended to check with your state office first before using a certain blast media
• Limited embedment – Crushed glass will not embed very much into the surface making it ideal for applications where embedment is problematic (like log cabins)

What are crushed glass Cons

• Expense – Compared to coal slag crushed glass can cost quite a bit more than coal slag
• Speed – Due to being softer than coal slag crushed glass can be slower at removing coating depending on the substrate it is removing coating from

Common Crushed Glass Uses

• Fiberglass coating removal
• Concrete Surface Preparation
• Steel surface preparation
• Wood – Use on wood will depend on the wood substrate certain woods are too soft and crushed glass could etch the wood (which is undesired)
• Brick

Coal Slag What is capable of

Much like crushed glass coal slag is used for a variety of applications from very light to heavy coating build up removal. It is capable of achieving mil profiles anywhere from 2 – 6 mils.  It also comes in a variety of mesh sizes.

Coal Slag Pros

• Lower cost – Typically coal slag cost less compared to crushed glass media
• Speed – Typically since coal slag is higher on the mohls scale it will be faster at blasting compared to crushed glass
• Environmentally friendly – many coal slag options have been approved to meet environmental requirements.

Coal Slag Cons

• Dust – Coal slag typically produces more dust than crushed glass which can be problematic in areas where visibility is critical or where neighbors will not be ok seeing dust from sandblasting

Coal Slag Common Uses

• Steel surface preparation
• Steel surface coating and rust removal
• Concrete surface preparation and coating removal