The company considered a modern trichloroethylene (trike) system and also looked at vapour degreasing using lower risk (and more expensive) solvents. There was a nagging doubt, however, whether in the coming years all volatile organic compounds will be subject to increasingly stringent controls.

Revill finally decided that aqueous cleaning was the way to go when one of its aerospace customers asked about the subcontractor’s plans for cleaning components. The manufacturer commented that the aerospace industry, which traditionally used trike for cleaning, now favours water-based degreasing of its components. Another major aerospace company was even more direct when it recently asked Revill’s operations manager Dave Moore what his plans were for switching from trike degreasing.

So the Exeter-based paint shop, which previously used nine tonnes of trike annually, has switched to an aqueous cleaning system from Turbex. Instead of solvent it uses water and two non-hazardous additives – detergent for degreasing and phosphate to coat the parts ready for painting. They are of such low environmental impact that the company has received wholehearted approval of its new process from both its local authority and water treatment company.

The company has found that the aqueous cleaning machine, which started operating on the Exeter site at the beginning of 2008, is just as efficient as trike at degreasing components. A major advantage, however, is that the Turbex machine is one fifth cheaper to run than the former trike system, as although electricity usage is a little higher, consumption of consumables is down and so too are labour costs.

The addition of a protective phosphate layer after aqueous cleaning means that it is no longer necessary to paint components straight away, as was necessary after degreasing with trike. Furthermore, the phosphate coat provides a better key for wet paint or electrostatic powder coating. Using tape, bend and cross-hatch tests, the subcontractor has confirmed the quality of the paint finish on components that have been processed in the aqueous machine.

Against a background of more and more aerospace OEMs and first-tier suppliers closing their internal plating and painting facilities and putting work out to subcontractors, Revill is particularly well placed to pick up additional contracts.

Part of the reason is the proximity of its sister company within the EIC Group, electroplating firm South West Metal Finishing, which is also in Exeter. Rapid transfer of components between the sites means that Revill is able to paint them soon after plating, which is important as the time lag between operations must be short to avoid degradation of the surface.

The group is able to offer a one-stop-shop service that includes not only finishing but also non-destructive testing of components, which is exactly what aerospace customers are looking for these days. South West Metal Finishing’s turnover is also biased towards aerospace contracts – around 70 per cent by turnover – and the company holds many industry- and customer-specific approvals.

Around two-fifths of parts received by Revill are plated, including from South West Metal Finishing. Some have already been cleaned before they arrive, while others require degreasing. Phosphating is not applicable with these components.

It is the other three-fifths of throughput that present the paint shop with more of a challenge. As a subcontractor, it is uncertain what parts will come in from week to week and what soils will be on them. Some could be aluminium castings that have cutting oil left on them from machining, while ferrous parts may have been coated with dewatering oil to prevent the surface from rusting.

Moreover, the material may not even be metal; Revill routinely receives plastics and composites to finish. There is also the wide range of different component sizes to contend with, which vary from small bracketry to the base of a flight simulator.

Continued Mr Moore, “With all of this in mind, we wanted the largest cleaning machine that we could fit into our factory and one that would be able to cope with virtually anything. The Turbex system, with its wash chamber dimensions of 2.1 by 1.2 by 1.2 metres and 2-tonne weight capacity, does just that.

“It means that we can clean rectangular parts up to 2.4 metres long and accommodate even larger, thin components across the longest diagonal, giving us more versatility than our previous, smaller trike tank.

“Overall we can process 25 per cent more parts in a single cycle, which is key to the efficiencies we are experiencing. We don’t need to run the Turbex machine as often, so chemical use is less than we expected and the labour element is also reduced.”

Mr Moore concluded, “All our customers benefit from the additional phosphating process after degreasing, provided that they want it of course, so we are providing a better service at no extra charge.”