The fine art of vintage car and automotive abrasive blasting
Gold Coast – 0403 942 016
The abrasive blasting of motor vehicles has a justified poor reputation as many vehicles have been damaged from the process to the point of “not worth repairing”. The warping, buckling and pitting of panels is caused by many factors, such as:
- heat (friction)
- air pressure
- grit size and type
- work hardening of the metal
- lack of technique and knowledge
- careless handling.
Many owners are not aware their vehicle has been damaged until informed by their panelbeater and the blasting operator may not even acknowledge they may have caused it!
There is no comparison between blasting steel girders and earth moving equipment to fragile motor vehicle panels. Also, if the vehicle has been coated with an industrial primer it needs to be removed if a quality paint finish is expected. There are many types of blasting materials available all claiming superior characteristics for the cleaning of:
Types of blasting material:
- bi-carb of soda
- plastic beads
- glass beads
- zinc slag granules and many others.
Each has it’s own use with advantages and disadvantages. Basically the formula is the less abrasive the material the more energy and time it takes to remove paint, body filler, rust scale and stain. Thus it is a balance between economics and effectiveness.
Regardless of what material is used it still comes down to the expertise of the operator. Experience and panel beater knowledge is essential when blasting motor vehicles, especially with large flat panels.
There are obviously other methods of stripping paint from a motor vehicle, such as paint strippers and mechanical sanding. Besides the cost of paint stripper and sanding discs it takes an enormous amount of time and frustration, plus the mess and health hazard to the operator and the surrounding area.
Acid dipping is another option with the advantage of treating box sections and inner sill panels, etc. The disadvantage is acid residue can remain active in joints and seams and can react on new paint work even though a neutralizing agent is generally used. Also proof coat and sound deadening material falls as a sludge into inaccessible areas such as turret rails, behind wheel arches and quarter panels. Some vehicles have aluminium panels, for example, doors, bonnets, boot lids and fenders which have completely disintegrated in acid baths.
PREPTECH, with years of experience, have mastered the art of abrasive blasting of motor vehicles, producing a clean, smooth, distortion-free surface, in preparation for outside-only re-sprays to total bare shell restoration.
For outside only re-sprays, parts need only to be removed as required by the spray-painter, for example, bumpers, mouldings, badges, lights, etc.
Glass, door jambs, air vents, engine bays are masked for protection to stop material from entering vehicle interior and ducting. If required, previous repairs to the vehicle (body filler) can be left in tact with only the colour and primer removed requiring only a “reskim” rather than creating a problem for the panel beater.
On complete restoration projects, the body shell is supported from damage during the blast cleaning of underbody areas, engine bay, floorpans, sills, etc.
After blasting the body shell and panels are cleaned from grit and dust,sill panels subframe rails and box sections are blown out with compressed air in preperation for etch priming.
As bare metal should be treated immediately a wash coat of single or two-pack etch is applied. The etch should be compatible with the intended paint system or as required by the spray-painter.
PREPTECH’S service includes pick-up and delivery in the Gold Coast area and the assurance and confidence that all care has been taken with your vehicle.