No products in the basket.
Overspray
Fuzz, Hazing, Overspray, Poor Melt In
Description
Areas of granular paint particles adhering to, or partially absorbed in the surface of the film.
Cause
Spray dust deposited on the surface. This results from:
a) Poor masking.
b) Paint from a subsequent application settling on the surface.
c) Compressed air pressure too high.
d) Inadequate extraction or ventilation.
Prevention
a) Mask carefully and completely, ensure that the edges of masking tape are thoroughly sealed.
b) Protect adjacent surfaces from spray dust.
c) Set compressed air pressure as low as possible, consistent with proper atomisation.
d) Use a spray booth, and ensure correct air circulation and extraction.
Rectification
Rub down with abrasive compound and polish.
Orange Peel
Inconsistency, Levelling, Orange Peel, Pebbling, Poor Flow, Uneven Application
Description
Pebbled, uneven surface of the paint film, similar in appearance to orange skin.
Cause
Failure of the paint droplets to coalesce on the surface.
This may be due to:
a) Poor spraying technique, spray gun too far from surface, incorrect compressed air pressure, incorrect nozzle adjustment.
b) Excessively thick or thin film.
c) Paint incorrectly mixed, wrong viscosity, poor quality or incorrect thinner.
d) Insufficient drying time between coats, cold air fanning to speed drying.
e) Incorrect ambient or surface temperature, draughts.
Prevention
a) Use the correct spraying technique and ensure that equipment is correctly adjusted.
b) Apply paint in thin even coats.
c) Ensure that the paint is correctly mixed, use only recommended thinner with the correct grade.
d) Allow sufficient drying time between coats.
e) Spray within the recommended temperature range and ensure proper ventilation.
Rectification
Rub out the orange peel, compound and polish. In severe cases it may be necessary to flat and repaint the surface
Lifting
Crinkling, Frying, Lifting, Puckering, Raising, Shrivel, Swelling, Wrinkling
Description
Shrivelling, swellings, wrinkles or folds of varying severity at the paint surface.
Cause
Non uniform drying within the paint film.
This may result from:
a) Excessive film thickness.
b) Insufficient drying time between coats, forced drying, non uniform air temperature.
c) Use of wrong or poor quality thinner.
Prevention
a) Apply paint in thin, even coats.
b) Allow sufficient drying time between coats, ensure correct, uniform drying temperature.
c) Use only recommended thinner.
Rectification
Allow the film to harden thoroughly. If the defect is slight, flat, compound and polish the affected area.
In severe cases rub down to the substrate and repaint.
Inadequate Colour Coverage
Grin Through, Inadequate Colour Coverage, Lack of Paint, Poor Coverage, Poor Hiding, Poor Opacity, Rub Through, Show Through, Thin Paint, Transparent Film, Undercoat Showing Through, Undersprayed
Description
Underlying surfaces visible through the paint film, most frequently in hard to spray areas, on lower panels or on sharp edges and contours.
Cause
Inadequate thickness or poor covering power of the colour coat. This is frequently due to:
a) Poor spraying technique.
b) Inadequate lighting, insufficient or cramped working space, inaccessibility of surfaces.
c) Poor mixing of materials.
d) Reduced thickness of the colour coat due to excessive compounding and polishing.
Prevention
a) Use the correct spraying technique, ensure even and adequate film thickness.
b) Work under good lighting conditions in a properly sized spray booth, pay special attention to inaccessible areas.
c) Ensure that the materials are thoroughly mixed.
d) Avoid excessive compounding and polishing.
Take special care on edges and sharp contours.
Rectification
Flat the affected area and repaint.
Hands on Metal
Finger mark, Fingerprints, Hands on Metal
Description
Also known as Finger Marks and Hand Print Blistering
Cause
No matter how clean the hands may seem, there is always some dirt, grease, oil or perspiration which will cause blistering and poor adhesion.
Prevention
Keep bare hands off the surface to be painted.
Rectification
In motor body assembly plants, cars are never directly touched with human hands. After being chemically cleaned – the operators wear cotton gloves. It is a good practice for all painters to follow.
Dry Spray
Dry Spray, Poor Wetting
DESCRIPTION
A granular or coarse textured finish with no gloss.
CAUSE
Paint being deposited on the surface in a powdery condition.
a) Viscosity of paint too high, use of incorrect or poor quality thinner.
b) Poor spraying technique, dirty spray gun, compressed air pressure too high, gun held too far from the surface during spraying.
c) Spraying in draughts or in a high velocity airflow.
PREVENTION
a) Use the correct proportion of recommended thinner.
b) Use correct spraying techniques, ensure that equipment is clean, set air pressure as low as possible, consistent with proper atomisation, spray from the correct distance.
c) Use a spray booth, and ensure that air circulation and extraction is at the correct velocity.
RECTIFICATION
Flat, compound and polish. If the texture is too coarse for this to correct the defect, rub down the topcoat and repaint. Metallic finishes must always be rubbed down and repainted.
Dirt
Bits, Dirt, Dirt Inclusions, Dirt Nibs, Grittiness, Seed, Specs
DESCRIPTION
A rough, irregular surface to the paint film is easily felt with the hand. The particles are often totally embedded in, and covered by the film.
CAUSE
Contaminating particles incorporated in the paint.
These may be the result of:
a) Dust, dirt or threads falling from cloth or clothing or blown out of mouldings or panel joints during spraying, setting on the wet paint film.
b) Dust not properly removed from the surface prior to spraying.
c) Airborne particles setting on and becoming incorporated in the paint film during or immediately after spraying.
d) Dirt in the paint or thinners resulting from open or rusty
PREVENTION
a) Ensure that cloths and clothing are clean and dust free, blow out mouldings and panel joints prior to spraying.
b) Clean down and tack-off the surface prior to spraying each coat.
c) Keep the spray shop clean and dust free, avoid sanding operations in the area of the spray booth. Wet down surrounding surfaces if necessary, ensure that the filtration system is working properly.
d) Keep all materials in clean, sealed containers and strain before use.
RECTIFICATION
Allow the paint to harden completely. Light surface dirt may be removed by flatting, compounding and polishing.
Deep embedded dirt, or dirt in synthetic paints, requires the surface
Cobwebbing
Cobwebbing, Webbing
Description
Paint issues from the spray gun nozzle and is accelerated by the airstream in which it divides into filaments which extend and break up. Failure of the filaments to break up or “atomize” is known as cobwebbing.
Cause
a) Use of cold paint which has thickened considerably.
b) Incorrect pressure and/or viscosity too high.
c) Use of cheap or incorrect thinner.
Prevention
a) Apply at correct pressure and viscosity.
b) Use correct quality thinner.
Rectification
Reduce air pressure and/or viscosity until cobwebbing disappears.
NOTE:
Some specialised materials, tank linings for example, are difficult to atomise and require special equipment to be sprayed successfully.
Clouding
Clouding, Colour Change, Floatation, Floating, Flooding, Haloing, Lapping Marks, Mottling, Patchiness, Ringing, Shadowing, Striping, Uneven Application
Description
Colour variation in metallic paint, with patches of lighter or darker tint, often in streaks following the direction of spraying.
Cause
Irregular application density of the basecoat.
This is a result of:
a) Poor spraying technique.
b) Poor pattern from the spray nozzle.
c) Paint too wet, insufficiently mixed paint, poor quality or wrong type of thinner.
d) Surface too hot or too cold.
Prevention
a) Use the correct spraying technique.
b) Adjust the nozzle to the correct pattern before commencing spraying.
c) Ensure that the paint is thoroughly mixed to the correct consistency.
Use only recommended thinner.
d) Ensure that the surface is within the recommended temperature range.
Rectification
If the clearcoat has not been applied, shade the base, otherwise rub down the surface and repaint.
Cissing
Cissing, Craters, Fish Eyes, Saucering
Description
Small, crater like holes or indentations in the paint surface, varying in size from pinholes up to 1cm in diameter. Usually the larger craters occur individually, whilst the smaller ones are often found in small densely packed clusters.
Small impurities are often visible in the centre of the crater.
Cause
Variations in the surface tension of the paint.
The most common reasons for this are:
a) Silicone in the environment or on the surface of the substrate; even minute traces are sufficient to cause cissing.
b) Contamination by other sources, such as grease, dried soap, detergent, spray dust, wax, or oil from the spray gun.
c) Incompatible elements in the primer.
d) Saturation by fumes in the spray booth.
Prevention
a) Thoroughly clean any silicone polishes from the surface to be painted and avoid using silicone polishes in the vicinity of the paint shop. Prepare the surface using the same preparation procedure as that set out below.
b) Thoroughly clean the surface with wax and grease remover. Do not allow cleaning solvents to dry on the surface but remove with a clean dry cloth, using the cloth only once.
Clean surfaces prior to sanding and always ensure that all sanding dust is removed. Prepare bare metal surfaces with metal conditioner.
Repeat the solvent cleaning operation prior to commencing spraying.
Ensure that the spray gun and compressed air equipment is properly maintained.
c) Always use the recommended materials.
d) Ensure that the spraying area is properly ventilated.
Rectification
Remove the paint completely from the affected area repaint, following the recommended preparation procedure.
In extreme circumstances it may be necessary to use an anti-cissing additive. Always consult the paint manufacturer before using such additives.