The first stage in restoring a rusty but restorable classic's bodywork is to have the body cleaned back to the bare metal stage. This stage must be completed before any form of panel beating or shaping can get underway.
Classic car restoration will usually involve working with dirty and rusty steel- steel panels that will be covered with original paint or a covering of rust or usually a combination of both,
Bringing this metal back up to a workable standard will involve a lot of filing and sanding – the only method of determining deformations and damage to the metal surface.
As any experienced classic car restorer will tell you, finding and eradicating these defects will act as a guide on how the overall bodywork renewal project will fan out.
Thankfully for the vehicle restorer, several methods can be employed to clean sheet metal.
There were only two options available at one time – neither of them very pleasant or particularly efficient.
The first method was to treat the metal by dipping it in a bath of hydrochloric acid.
There was always the trusty blow torch for those who chose not to take this path- a ponderous method of burning off old paint.
Nowadays, body shops provide a variety of solvents developed for the specific purpose of removing paint and cleaning metal surfaces - rapidly and efficiently
If the problem area is not t00,1,3,400,0,300,0,0,0,0,1">oo widespread, some body shops prefer to use the tedious method of sanding, although it does remove surface rust along with paint and can be done in-house without all the noxious fumes that come with any form of chemical dipping.
There are a number of devices with a spinning surface that can be used in sanding, with abrasive sandpaper head, plastic mesh discs or wire brushes for heavy work being the favoured method of cleaning metal.
Experienced restorers are usually more than happy to farm out the dip stripping process to specialist contractors who should have the proper facilities to carry out the job safely and efficiently.
They will be aware of the importance of dealing with a well-established contractor with a flawless record, as the quality of work can vary considerably in quality and effectiveness.
In recent years abrasive blasting, sometimes called sandblasting, has become common practice in metal cleaning.
Once again, while it is an attractive proposition to farm this task out, it is of the utmost importance to find one who know what they are doing.
Sub standrad work can destroy panels that were restorable or leave a lot of blemishes on the method that will involve time and expense to remove them.
An experienced sandblaster will know how to leave the vehicle's contours intact, ultimately making for a much more successful paint job.An experienced sandblaster will know how to leave the vehicle's contours intact, making for a much more successful preparation and paint job.
Trained and disciplined professionals will never allow themselves be rushed to complete a sandblasting project simply because they know that the best and safest means of blasting sheet metal is to take their time.
The most commonly used material in blasting metals are either soda and polystyrene beads, not because they remove deep, pitted rust particularly well, but because they prevent "warping" as well as being gentler on the metal surface.
Bodyshops that are more concerned about removing rust than preserving shape will use harder media such as aluminium oxide, copper slag, silica sand and tungsten carbide, which will provide a very clean surface.
Once again, this blasting method requires a lot of time, as the operator needs to know how to constantly adjust the angle and distance of the nozzles from the target metal.
What must be taken very much into account when it comes to blast cleaning any metal surface is that when the job has been completed, the surface is very vulnerable to the effects of moisture in the air, which could cause rust to form almost immediately.
