Paint Defects

Paint defects

General about paint work defects
To facilitate communication concerning paint work defect, between Volvo Car Corporation and importers and between importers and dealers the most frequent paint work defects have been given codes.
The following is an extract from Volvo Standard as applies to defect codes.





The following are examples of paint work defects.

Sealing-, adhesive-, or primer residue

Cause
Sealant applied too liberally. Deformation in the panel or sealant application.

Action
Remove the defective sealant. First apply primer, then new sealant and paint.

Corrosion smooth surfaces

Cause
Mechanical damage to the panel (stone chips).
Moisture and water damage to bare metal before painting
Fingerprints on bare metal.

Action
Stone chips that have not developed creeping corrosion are treated according to recommendations in the car instruction book.
If the damage is widespread or the cause is damp, water or fingerprints which occurred in the manufacturing process, sand back to bare metal and build up the paint coats from the beginning.
Stone chips, from for example studded tires, occur frequently and are regarded by many customers to be due to defective paint. A good rule when inspecting and discussing with customers is to compare the paint work in the stone chip risk zone with the headlamp lenses and the windshield etc.

Corrosion in the seams

Cause
Sub-standard welding, incorrect weld sealant, unsealed seams allowing moisture to seep in, incorrect adhesive.

Action
The seam is sandblasted and repainted. When the paint has dried treat the seam with rustproofing agent.
Treat the interior of the seam with penetrating rustproofing fluid.

Creeping corrosion

Cause
Creeping or filiform corrosion occurs when the painted surface is missing for some reason, stone chips or a damaged panel for example, and spreads if the panel is not pre-treated to prevent this.

Action
Sanding the affected surface to bare metal and repainting.

Color patches in the paint

Cause general
Old paint.
Badly mixed paint.
Paint that has been in the spray bowl for too long.
Incorrect amount of hardener.
Incorrect viscosity or thinner.
Incorrect air pressure.
Mixture of different makes.

Cause metallic
Metallic too dark - base metallic sprayed too wet.
Metallic too light - base metallic sprayed too dry.

Action
Sand down the color coat and repaint. Use P 600 wet sandpaper.
Adjust the shade carefully through a spray test.

Color run, drops

Cause
Paint viscosity too low.
Color coat sprayed too thickly in some places.
Too short drying times between applications.

Corrective action, metallic paint
Remove the paint run carefully with a razor blade.
Sand lightly with P 1200 sandpaper and polish.
If this does not give satisfactory result, polish and paint the whole area.

Corrective action, non metallic paint
Carefully remove the paint run with a razor blade.
Sand lightly with P1200 sandpaper and polish.

Dirt in paint

Cause
Dirt particles in the air in the spray box (dirty intake filter).
Inappropriate work clothing.
Poor cleaning.
Dirt in the paint.
Badly cleaned paint filter.
Old paint.
Contaminated spray air.

Action
Trapped particles which are not acceptable to the customer are sanded and polished.
Respraying should only occur if sanding and polishing does not give a result and if less dust can be guaranteed when repainting.

Orange peel, matt paint

Cause
Thinner evaporated too quickly.
Incorrect viscosity (too thick)
Humidity in the spray box too high
Incorrect spray pressure
Coat too thick.
Temperature difference paint and surface.
Uneven drying.

Action
Sand the color coat with P 400 or P 600 sandpaper until orange peel disappears.
Polish with polishing paste and polish.
If this is not successful repainting is necessary.

Paint coat too thin

Cause
Inadequate spraying

Action
Note that certain interior areas such as the engine compartment and cargo compartment accept thin paint. The seats and upholstered areas inside the car also accept thin paint.
On exterior surfaces sand the paint with P 400 or P 600 sandpaper and respray.

Spray mist, masking faults, visible paint seams and other visible touch-ups brush strokes for example

Cause
Masking not correctly applied (bad masking).
Spray pressure too high.
For some reason the paint work repairs or brush retouching carried out in the factory have not had a satisfactory result.

Action
Either just polishing or alternatively first sanding then polishing. Do not polish edges.
Paint mist should only be sanded if polishing does not give a satisfactory result. Paint is sanded matt and apply topcoat.
Surfaces can be improved by spot retouching or by limited repainting of the necessary area.

Sand scratches in the panel or primer

Cause
Sanding edges, sanding holes, sanding scratches, circular scratches or breaks.

Action
Lighter scratches can be removed with P 1100-1200 sandpaper and polishing.
Only deeper scratches are sanded, filled and repainted.

Scratches in paint

Cause
Scratches from sharp objects, polishing marks or cleaning scratches.

Action
Smaller scratches can be treated with polishing paste and polish.
Deeper scratches are sanded down with P 1200 sandpaper, polished with polishing paste and then polish.
Scratches down to the undercoat are filled with paint and polished. Respraying may be necessary.

Cracking

Cause
Coat too thick.
Oven temperature too low.
ultra violet radiation on metallic paints (applies especially to hot climates)

Action
Grind down to primer with P 320 sandpaper.
Build up new color coat.

Blistering

Cause
Hand sweat
Hard water
Badly cleaned surface.

Action
Sand down to primer with P 320 sandpaper.
Build up new color coat.

Craters in the paint ("fish eyes")

Cause
Silicon in the atmosphere or in the paint.
Oil or water in the compressed air.
Thinning too "quickly".
Incorrect thinning.
Incorrect oven temperature.
Incorrect paint viscosity - too thick
Too short evaporation time before baking. Should be 10-15 minutes.
Excessive application at high temperature

Action
Sand the area down to bare metal and repaint.
If craters only occur in the color coat the paint does not need to be sanded down to bare metal.

Flaking paint, peeling edges or stone chips

Cause
Poor cleaning.
Poor adhesion.
Incorrect paint selection.
External mechanical causes, for example stone chips.
Mechanical causes after vehicle has passed Quality control, in transport.
Paint coat too thick, for example after touching up.

Action
Touch up with (paint) brush or respray.
Sand down and build up a new paint coat.
Check adhesion of topcoat by applying tape and pulling away suddenly. If the top coat adheres to the tape sand down to primer (Use P 230 sandpaper). Then build up a new paint coat.

Atmospheric effects on paint (oils, bird droppings etc.)

Cause
Aggressive chemical substances such as limestone, cement, rust and acid vapor, affect with moisture mainly affect horizontal surfaces. Bird droppings, oils, soot, degreasing agent etc.
Droppings, especially those of sea birds corrode painted surfaces.

Action
Slight color change is affected by sanding with P 1200 sandpaper sandpaper and polishing. For heavy staining sand and build up a new paint coat. Apply primer to areas that are sanded through to bare metal.
Wash immediately when discovered. If the damage is too great respraying is required.

Mechanical effects on the paint (spark shower)

Cause
Rusty metal particles, industrial emissions for example, on horizontal painted surfaces. Spark showers from overhead railway, streetcar or trolley bus cables etc.

Action
Wash with 3% oxalic acid and then thoroughly with water. Polishing may be necessary for heavy damage. If particles are embedded deep in the paint respraying is necessary.