Preparing Concrete Using A Shotblaster

Shotblasting is one of the oldest and most economical methods of levelling and preparing a concrete floor but, as with any concrete preparation method, some important points should be noted before embarking on any project.

A shotblaster is a highly specialised machine that works by forcibly propelling fine steel beads or ball bearings onto the surface at high velocity using centrifugal force to create a ‘sandpaper’ effect.   This is done in a controlled pattern and direction to remove thin surface deposits such as dirt, grime, coatings, curing compounds, paint or other contaminants.

These machines are also useful for cleaning and profiling a concrete floor in preparation for the application and adhesion of coatings, overlays and decorative toppings and can also be used for aesthetic purposes, such as etching stencils or floor graphics.

Another good thing about using a shotblaster is that they leave the surface dry and ready for the next stage, so you can get going immediately.

A number of factors control how deep the surface removal is - including the size and concentration of the metal beads, the rate at which the shotblaster travels, the impact force of the beads and the properties of the existing coating.   You can vary the travel speed of the machine and the size of the beads to achieve the desired results.

TIP : If you want an aggressive, more open profile in preparation for a thicker coating such as a tile, run the machine on a slower drive speed and use larger beads.  For a lighter profile, better coverage and higher production rates (for example if you’re going to apply a thin coating or sealer, or even simply leave have the concrete floor surface bare), run smaller shot through the machine with a faster drive speed.

It’s important to note that while shot blasting is an affordable option for concrete resurfacing, it’s not always the best choice especially when thick or heavy elastomeric coatings, deep stains or rubbery mastics need to be removed.   With thicker coatings such as urethanes, the shot can simply bounce back and whilst it is possible to do several passes with the machine to remove the thick coating, some shot blasters can leave visible paths as a result of the overlap of successive blast lines.  If the finished coating or overlay is to be a thin, clear epoxy or urethane, these imperfections will show through.

Shotblasters come in various different sizes and models, all of which require vacuums.  They are typically walk-behind or ride-on models, with smaller machines ideal for working in tight areas like next to walls, around equipment and into corners.

You also need to know that shotblasters are powerful machines and require a fair amount of skill and care to avoid damaging the floor and achieve optimum results. 

TIP : Make sure you hire your shot blasting machine from a professional company that asks all the right questions upfront to ensure you get the most appropriate concrete equipment, steel shot and steel grit for the job.

We’ll use our decades of experience in the concrete industry to help you make the right choice of concrete equipment.  We’ll find out as much as possible about your project before making  recommendations and we’ll make sure that whatever concrete equipment you hire, it will meet your expectations in terms of price and performance.  Give us a call on 1300 048 521 or have a look at our extensive range of concrete equipment for hire in Perth