• DEFECT

    Rust Staining

     

     

     

    Yellowing

     

    Chalking

     

     

    Scum  

     

     

    Bronzing

     

     

     

    Loss of Gloss

     

     

     

     

     

     

    Cracking

     

     

     

    Blistering

    Flaking

     

     

     

     

     

     

    Staining

     

     

     

     

    Water Marking

     

     

     

     

     

     

     

     

     

     

    Water Spotting

     

     

     

     

     

     

    Black Spotting

     

     

     

     

     

     

     

     

     

     

     

     

     

     

    Industrial Fallout       

     

     

    CAUSE

    Seeping from seams that are rusting inside.

     

     

    Atmospheric conditions ie. industrial pollution.

    White powdery deposit due to weather erosion of the surface leaving loose pigment particles. Milky appearance ingrained in the surface caused by continual washing in hard water.

    An iridescent "bloom” appearing on blues and Maroons, due to pigment action used in the colour.

     

    Associated with chalking ie.,  erosion of the  medium,  or microcracking due to age. Maroons and single layer metallics especially on bonnets will suffer most. Cellulose paints are most prone.

    Embrittlement of the paint on ageing. From fine surface cracks to deep            cracks through the colour.

    See "Blistering" info.

    Paint Film lifting and breaking away from the substrate. Excessive film thickness (several repaints). Embrittlement due to natural ageing.

    Poor preparation (inadequate sanding on window surrounds). Areas around stone chips.

    Contact with road tar, lubricating greases and petrol, rubber components.               

     

     

    Marks and depressions in the paint film occurs more on lacquer (cellulose and acrylic) than on fully cured 2K or hard dry synthetic.

    More especially on new paint becoming slightly thermoplastic under the sun. If heavy rain falls, it will settle in large drops (especially if the paint is waxed) and make a contour.

    Bleaching of the paint caused by rain drops. More severe when Cause by acidic rain ie. rain falling through atmospheric layers of industrial contamination. Can cause bad discoloration, particularly on blues and reds.

    Associated with Cadmium pigments (red. orange, yellow) and can occur on all types of paint. Note that this is an infrequent fault now, as Cadmiums in both OE and refinish have been superseded by pigments that are either free from the defect, but expensive, or cheaper but prone to the ordinary water spotting problems mentioned above. Therefore, the so-called black spotting” may well be classified as general water spotting.

    Soot or ash particles    from factory chimneys (viz. steel works) become embedded in the paint film, imparting a rough surface. Can sometimes be seen as tiny metallic looking spots. In severe cases the sulphurous particle can eat down through the paint film.

    Usually happens when vehicle is parked close to heavy             industrial areas.

                                       

     

     

     

    RECTIFICATION

    Clean off paintwork with compound or polish.

    Application of sealant to seam will prevent recurrence temporarily.

    Remove with compound, failing this, flat and re-colour.

    Will polish off, but usually recurs. Permanent solution is to flat back to sound surface and repaint.

    Use super cut to revive the colour.

     

     

    Will polish off easily with No. 7 or super cut.

     

     

    Can be temporarily revived with compound and polish. Flat, undercoat and re- colour for permanent rectification. Avoid spot repairs with cellulose over OE on horizontals.

     

    Thoroughly flat, apply undercoat and colour. Severe cases need to be stripped back to metal.

     

    Strip and repaint.

     

     

     

     

    Local areas sand back to firm feather edge, etch prime, undercoat and colour.

    Remove contaminant with compound and polish away the stain. Heavy staining needs flatting away, or even stripping before repaint.

    Flat (with P1200 paper) and polish.

    If too deep, fully flat with P800 and recolour.

     

    Remove any wax with white spirit before flatting.

     

     

     

     

    Does not often respond to polishing. Flat and repaint. SR Undercoat caused       or Isolator 85 must be used to prevent contaminant leaching through to new colour coat.

     

     

     

     

     

     

     

     

     

     

     

     

     

     

     

     

    As with Water Spotting, compound and polish.

    For heavier contamination 10% oxalic acid solution (2oz per pint of water) carefully, applied for 15 mins to affected areas, then thoroughly rinsed off with clean water.

     

    Note: Oxalic acid is a poison and all precautions must be taken, ie. gloves. Goggles, to prevent contact with skin and eyes.

    If this treatment is not effective, than strip and repaint.

    Let us take a look at some of the causes and rectification of application problems.