Global Technologies Racing Ltd (GTR), the Fontwell, West Sussex, UK, based specialist designer and manufacturer of high specification carbon fibre components for Formula 1, Indycar and other state-of-the-art racing and performance cars, has recently installed its second Vapormatt wet blast machine.
The new machine – a ‘Panther’, with a 995mm x 700mm x 700mm processing enclosure – is used for the surface preparation of post-cured parts prior to painting or coating. It joins an existing ‘Vapormate 1’ machine with a 700mm x 700mm x 700mm enclosure, which is used for the surface conditioning of carbon fibre surfaces prior to laying-up and bonding.
Global Technologies Racing opted for the wet blast surface treatment process following thorough trials by Vapormatt, which established its superiority over comparable systems for the surface preparation of carbon fibre and other composite materials such as glass reinforced polyester (GRP).
When working with composite materials used in safety-critical applications in the motor racing and aerospace industries, precise and dependable surface preparation for bonding and coating is obviously of paramount importance. Both carbon fibre and GRP are notoriously difficult to bond, due to the presence of resinous material on the normally smooth surface. Grease and dust also compromise effective adhesion.
The Vapormatt wet blast process utilises water and fine abrasives in suspension, delivered by a slurry pump and accelerated by compressed air to the process nozzle, which is normally manually operated (automatic nozzle manipulation is also available for dedicated, repetitive tasks). The action of the slurry scours the surface to create a thoroughly clean and lightly abraded result. The water can be heated and mild detergent added to ensure the effective removal of grease or oil.
The ratio between the water pressure and air pressure in the process nozzle is variable, to enable a “water buffer” to be maintained between the abrasive media and the surface being processed. This water buffer effect has a number of major benefits. It lubricates the action of the media, eliminates static build-up and washes the surface continuously during processing. Added to this, it prevents impregnation of hard abrasive particles into the soft resin surface and prevents fibre damage.
Because of its inherent advantages, the Vapormatt wet blast process has superseded the use of hand abrading in many composite surface preparation applications – overcoming the inconsistencies of the latter and also eliminating the need for further chemical cleaning.
The Vapormatt process is also highly effective for preparation of the complex automotive components manufactured by Global Technologies Racing, which are difficult and time-consuming to prepare with conventional manual methods.
No solvents or other potentially hazardous chemicals are used by the wet blast process, so it is not subject to stringent EU solvent emission, VOC or dust emission legislation.
