When preparing and restoring a specific substrate in preparation for protective coating application, it is essential to ensure a complete clean surface clear of corrosion, paint, weld slag, grime, oil, salt deposits and dust. This to guarantee the coating chemistry is not compromised once applied to the surface profile.
There are numerous methods of achieving this, however sandblasting is largely considered the ideal surface preparation technique and the most effective process. For optimal results the process should always be completed by an experienced, reputable sandblasting company. Although sourcing the appropriate technician can be tedious. Asking the right questions of your potential sandblaster can help to determine whether they’re the right person for the job. Here are some helpful questions to ask.
With a wide variety of sandblasting media to choose from, consisting of everything from Garnet to plastic abrasives, it is vital that the contracted sandblasting company determine the ideal abrasive for the project and substrate being treated. Certain abrasives may be deemed too aggressive for the specific application and if incorrectly applied can result in damage to the underlying surface. Alternatively, a fine or light abrasive may be too subtle and ineffective in attempts to remove thick coatings or corrosion. By discussing the sandblasting media with the specialist prior commencement, you can determine whether they’re the right service provider for your needs.
Are your sandblasters covered by public liability insurance, professional indemnity insurance and workers compensation? Have they provided you a detailed Safe Work Methods Statement outlining the scope of the project to be undertaken? If your sandblasters do not possess this crucial paperwork avoid them and seek alternate companies, as they clearly do not priorities Occupational Health & Safety in their daily practices. Ask for all relevant documentation and have the confidence in knowing your sandblasters are covered in the unlikely event of an onsite incident.
All sandblasting projects begin by completion of a small sample undertaken via a “test blast”. This not only allows the sandblasters to accurately regulate the appropriate abrasive and pressure to apply to the surface, but also to determine the desired finish the client desires. Once permission to proceed has been granted by the client as a result of the sample, this finish is then replicated throughout the remaining surface area. It is recommended you check in with your sandblasters at the beginning of every day to ensure consistency of appearance and update them of any new onsite developments from a safety standpoint for the day ahead.
Sandblasting onsite can be a complex and potentially hazardous process, so it’s vital that strict safety precautions are implemented for the wellbeing of technicians, contractors and general public. Before commencement, sandblasting companies must construct 360-degree encapsulation, to ensure all abrasive, dust and waste remains within the dedicated exclusion zone. Further, the use of dust collectors to create a negative pressure environment is recommended to additionally control airborne contaminants. Employing appropriate signage reading “Sandblasting in Process” or “Authorised Person Only” is also suggested to increase public safety. Furthermore, all sandblasting operators will wear blast suits and air fed helmets being supplied from a fitted air filtration system, as well as general onsite personal protective equipment. Post sandblasting, leaving a clean and tidy site and correctly disposing of the spent abrasive is of the upmost importance. Ensure your sandblasters remove all waste to limit any potential onsite risks.