Wynnum Car Renovators Panel Beating & Towing (WCR) is a medium sized spray painting and panel beating workshop which employs eight staff. Over the years, Peter Watson (Manager of WCR) has been continuously thinking of ways to improve his business productivity, reduce operating costs, and help protect the environment.
He has to date introduced a number of waste reducing work practices including:
- the recycling of cardboard and metal parts;
- the re-use of coolant where possible; and
- the use of a gun-wash station.
Peter also uses High Volume Low Pressure (HVLP) spray guns, High Solid Paints (HSPs) and a Dustless Sand Blaster, which help minimise environmental pollution and provide the subjects for this case study.
High Volume Low Pressure Spray Guns
Peter has found that by using the HVLP guns he saves money on paint costs and reduces paint particulates and volatile organic compounds (VOCs) emissions into the environment.
These guns work by atomising the paint with a higher volume of air at a lower pressure. The lower pressure results in reduced paint dispersion and 'bounce-back', which translates to more paint reaching the job surface and less in over-spray.
By using the HVLP guns, Peter now only needs 2 litres of paint for a typical job compared to the 3 to 3.5 litres which was previously consumed. This results in annual savings well in excess of $3,000.00.
High Solid Paints
The use of High Solid Paints (HSPs) helps to further protect the environment in a cost effective way. The advantages of these paints are their lower solvent content and their production of thicker coats. This means that VOC emissions are minimised when these paints are used, and less time is required to spray paint a car: with conventional paints, six coats are required, but with HSPs, only two coats are needed.
Used in conjunction with HVLP guns, this constitutes a Best Practice method in the auto refinishing business.
Paint strainers are conical in shape and are made of a composite of paper and synthetic fabric. The paint filters through the holes in the fabric and solid particles of paint and debris are removed.
These strainers are more commonly used for a once only application and then discarded. Whilst it is best to use new strainers for paints used in the finishing coats, Peter found the strainers can be reused for undercoat applications where the requirements are not so stringent.
Through cleaning and reusing the strainers, a box of 270 strainers now lasts six months instead of two, effectively reducing usage by 67%. With each box costing $90.00, Peter currently spends $180.00 per annum on paint strainers as compared with $540.00 previously, realising an annual saving of $360.00.
As well as cost savings, reusing the strainers saves space in the Industrial bin and reduces paint contaminated wastes going to landfill.
Dustless Sand Blaster
Peter uses a sand blaster fitted with a dust extraction unit to effectively remove rust from car body surfaces. It has a 90% efficiency rate for rust removal compared with the conventional blaster which has an average efficiency rate of only 70%.
With conventional blasters, airborne dusts containing heavy metals and other toxic substances are generated, and settle all over the surrounding areas, impacting on workers’ health and contaminating the surrounding ground and waterways.
With the dustless sand blaster, these harmful pollutants are effectively contained. The blasting nozzle is enclosed in a dust extraction unit which captures the outfall and directs it into a vacuum unit, where the lighter particles and debris are removed from the heavier abrasives (sand in this case), which are subsequently reused in the blasting process. As this machine is hired, all servicing and waste disposal is taken care of by the rental company.
Another feature of this system is that the sand medium can be reused several times before it needs to be replaced, making the system convenient and cost effective to use.
Other benefits of the system include:
- Its capability to blast close to the glassed areas of the car (windows, wind sheild) as the outfall is contained; and
- Its protection of the operators’ hands and skin from damage by the abrasive outfall.
- Finishing Orbital Sander
- This system is used for dry rubbing and is effective from an environmental point of view because it does not require the use of water. Not only is water saved, but it gets the job done in half the time of traditional sanding.
Disc Sanding Gauze
Peter also uses a disc sanding gauze for wet rubbing. It eliminates the need to use a sponge and bucket and it saves time and money. It takes 1 sheet of gauze ($1.00 each) and 2 hours to complete an average sized car, compared to 8 sheets of sandpaper (also $1.00 each) and 4 hours to sand the same car by hand. The saving in labour and material costs is obvious.
When door panels are repaired, the water proof linings between the door frames and the interior panels need to be replaced. Normally, new plastic sheets are used for this purpose, but it was found that the plastic wrappings from new bumper bars serve just as well. Reusing the plastic wrappings helps to reduce the volume of non-biodegradable wastes (plastic) going to landfill, and saves money at the same time.
This innovation, together with those discussed above, enable WCR to operate in an environmentally friendly and cost effective way.