togwt
08-11-2011, 01:36 PM
Cause: the wrong paint-gun pressure and/or distance from panel, an operator not knowing how to set-up the equipment for that particular type of paint, using the wrong gun tip or even a partly blocked paint-gun nozzle, improper pre-paint preparation and /or paint application, or uneven drying of the clear coat.
Effect: a paint film surface that has a dimpled appearance, very much like the texture of an orange, hence its name. It’s the appearance that paint takes on due to an equipment/operator caused defect?
It should have be eliminated after the final shooting of clear coat by the OEM wet sanding the paint film surface, and polishing with a mildly abrasive polish and a high-speed rotary polisher. Be cognizant that some degree of orange peel can be found in most finishes, both OEM and repainted.
Solvents hold the pigment molecules in suspension and help provide an even distribution as they are transported through the air in a liquid form and onto the surface. The main purposes of the solvent are to adjust the curing properties and viscosity of the paint. It is volatile and does not become part of the paint film. It also controls flow and application properties, and affects the stability of the paint while in liquid state.
Once the paint reaches the surface, the solvents outgas (evaporate) leaving the paint to become solid and dry. The solvent carrier system is used to suspend pigment agents, urethane, polyurethane, and other molecules that will be left behind once the solvents evaporate. Solvents also facilitate the paint to remain viscous (thin): that is they thin out the liquid solution to be less like oil and more like water.
Volatile Organic Compounds (VOC) Regulations
A viscous liquid is easier to atomize as it comes out of the paint gun tip, and the more solvent that is present in the liquid: the longer it will take to begin to become sticky/tacky, and the longer it will take to dry. The longer it takes for the paint to dry, the flatter the paint will end up as the drops have plenty of time to settle into a flat surface. Before the volatile organic compounds (VOC) regulations came into force it was common for paints to have 75%+ solvent content (that is, 75% or more of the solvent would evaporate into the air) now to be compliant with VOC regulations paint is limited to a maximum 50% VOC content or less.
Solvent-based paints are categorized by the ratio of solids (resins, pigments, binders, etc.) to liquids (solvents) In the US manufacturers are required to use high solids paints, with a ratio of about 60% solids to 40% solvent. In order to produce a better flow rate a higher percentage of solvents is required, however due to recent volatile organic compound (VOC) limit restrictions; the 60/40 percentage cannot be exceeded.
In 1980 the US Government began to get involved with the paint process used by auto makers, namely the volatile organic compounds (VOC) content of the petroleum based paints and solvents being used. The allowable emission limits of VOC were subjected to dramatic cutbacks.
VOC’s are organic chemical compounds that have high enough vapour pressures under normal conditions to significantly vaporize and enter the atmosphere. These restrictions stem from the (US) Environmental Protection Agency (EPA) limits on volatile organic compound, which are in almost all solvents.
In other countries (i.e. EU) these restrictions either don`t exist or are more lenient, allowing manufacturers to use low solids paints (as low as 30% solids to 70% solvent), which tend to have a smoother appearance. To combat these restrictions paint companies are developing new technologies.
High or Low Solids
Is a ratio of paint to solvents - High is 60/40) that leaves more material (coverage) once paint has cured. Low is (30/70, which means the paint contains more solvents, once they have out-gassed (evaporated) which leaves a thinner coat (paint thickness)
South Coast California Air Quality District (AQMD) now requires that multi-stage clear coats have a 250g/L (2.1 lb/gal.) VOC emissions rating or better AQMD, Rule 1151
Water-based (Waterborne) paints, for example, are essentially low solids paints (up to 60% solvent), but they are legal because de-ionized water is used as the solvent, as opposed to volatile organic compounds (VOC). In addition to the low solids aspect, waterborne paints have many other neat properties that help improve the performance and appearance.
Water-based Paint
In reality, water-based (waterborne) automotive paint finishing is actually not that new; PPG water-based paint has been used by some OEMs since the early 1990s Water-based clear coat s are softer than acrylic oil based paints; due to the quick forced dry process using higher curing temperatures, which causes the paint to dry fast, but not as hard. As a result, these paints scratch more easily. They also have difficulties with increased orange peel and production line runs and sags, due to uneven drying of painted panels. The increased orange peel causes a reduction in overall smoothness and gloss.
Orange Peel
Correction- check the paint with a PTG to see how much paint there is available before attempting repairs OEM clear coat is usually very thin, and by using an abrasive to remove orange peel may remove too much paint. A clear coat that is too thin loses its ability to adhere effectively (delaminating) to the underlying paint layer and will flake off.
A vehicle with its original paint has a higher re-sale value than a repaint. Due to the above; something else to consider is a ‘do nothing’ option and learn to live with it.
Orange peel can be removed by wet-sanding but this entails a substantial reduction in clear coat thickness. If you try to wet-sand it perfectly smooth the chances are that you`ll breakthrough the clear coat, causing more severe problems than the orange peel, which may eventually entail repainting. A vehicle with its original paint has a higher re-sale value than a repaint. Due to the above; something else to consider is a ‘do nothing’ option and learn to live with it
Reduction - the way light is reflected from a paint surface affects the vehicles appearance after it is detailed. Reflection of light is either Specular (mirror-like) or Diffused (retaining the energy, but losing the image) depending on the nature of the surface. It is also possible for reflection to occur from the surface of transparent media, such as water or glass.
A paint surface that has `orange peel` diffuses the light reflection; a sealant or coating will highlight the orange peel effect as they reflect Specular light (mirror-like) meaning a reflection of the exact image, whereas organic wax reflects a Diffuse light, which is a ‘fractured’ image, an organic wax also shares this reflection trait in the so-called `wet-look` (jetting) So by applying a Carnauba wax to a surface that has `orange peel` you are not masking the effect, but disguising it by making the rest of the paint diffuse light reflection in a similar way.
Authors Profile
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Effect: a paint film surface that has a dimpled appearance, very much like the texture of an orange, hence its name. It’s the appearance that paint takes on due to an equipment/operator caused defect?
It should have be eliminated after the final shooting of clear coat by the OEM wet sanding the paint film surface, and polishing with a mildly abrasive polish and a high-speed rotary polisher. Be cognizant that some degree of orange peel can be found in most finishes, both OEM and repainted.
Solvents hold the pigment molecules in suspension and help provide an even distribution as they are transported through the air in a liquid form and onto the surface. The main purposes of the solvent are to adjust the curing properties and viscosity of the paint. It is volatile and does not become part of the paint film. It also controls flow and application properties, and affects the stability of the paint while in liquid state.
Once the paint reaches the surface, the solvents outgas (evaporate) leaving the paint to become solid and dry. The solvent carrier system is used to suspend pigment agents, urethane, polyurethane, and other molecules that will be left behind once the solvents evaporate. Solvents also facilitate the paint to remain viscous (thin): that is they thin out the liquid solution to be less like oil and more like water.
Volatile Organic Compounds (VOC) Regulations
A viscous liquid is easier to atomize as it comes out of the paint gun tip, and the more solvent that is present in the liquid: the longer it will take to begin to become sticky/tacky, and the longer it will take to dry. The longer it takes for the paint to dry, the flatter the paint will end up as the drops have plenty of time to settle into a flat surface. Before the volatile organic compounds (VOC) regulations came into force it was common for paints to have 75%+ solvent content (that is, 75% or more of the solvent would evaporate into the air) now to be compliant with VOC regulations paint is limited to a maximum 50% VOC content or less.
Solvent-based paints are categorized by the ratio of solids (resins, pigments, binders, etc.) to liquids (solvents) In the US manufacturers are required to use high solids paints, with a ratio of about 60% solids to 40% solvent. In order to produce a better flow rate a higher percentage of solvents is required, however due to recent volatile organic compound (VOC) limit restrictions; the 60/40 percentage cannot be exceeded.
In 1980 the US Government began to get involved with the paint process used by auto makers, namely the volatile organic compounds (VOC) content of the petroleum based paints and solvents being used. The allowable emission limits of VOC were subjected to dramatic cutbacks.
VOC’s are organic chemical compounds that have high enough vapour pressures under normal conditions to significantly vaporize and enter the atmosphere. These restrictions stem from the (US) Environmental Protection Agency (EPA) limits on volatile organic compound, which are in almost all solvents.
In other countries (i.e. EU) these restrictions either don`t exist or are more lenient, allowing manufacturers to use low solids paints (as low as 30% solids to 70% solvent), which tend to have a smoother appearance. To combat these restrictions paint companies are developing new technologies.
High or Low Solids
Is a ratio of paint to solvents - High is 60/40) that leaves more material (coverage) once paint has cured. Low is (30/70, which means the paint contains more solvents, once they have out-gassed (evaporated) which leaves a thinner coat (paint thickness)
South Coast California Air Quality District (AQMD) now requires that multi-stage clear coats have a 250g/L (2.1 lb/gal.) VOC emissions rating or better AQMD, Rule 1151
Water-based (Waterborne) paints, for example, are essentially low solids paints (up to 60% solvent), but they are legal because de-ionized water is used as the solvent, as opposed to volatile organic compounds (VOC). In addition to the low solids aspect, waterborne paints have many other neat properties that help improve the performance and appearance.
Water-based Paint
In reality, water-based (waterborne) automotive paint finishing is actually not that new; PPG water-based paint has been used by some OEMs since the early 1990s Water-based clear coat s are softer than acrylic oil based paints; due to the quick forced dry process using higher curing temperatures, which causes the paint to dry fast, but not as hard. As a result, these paints scratch more easily. They also have difficulties with increased orange peel and production line runs and sags, due to uneven drying of painted panels. The increased orange peel causes a reduction in overall smoothness and gloss.
Orange Peel
Correction- check the paint with a PTG to see how much paint there is available before attempting repairs OEM clear coat is usually very thin, and by using an abrasive to remove orange peel may remove too much paint. A clear coat that is too thin loses its ability to adhere effectively (delaminating) to the underlying paint layer and will flake off.
A vehicle with its original paint has a higher re-sale value than a repaint. Due to the above; something else to consider is a ‘do nothing’ option and learn to live with it.
Orange peel can be removed by wet-sanding but this entails a substantial reduction in clear coat thickness. If you try to wet-sand it perfectly smooth the chances are that you`ll breakthrough the clear coat, causing more severe problems than the orange peel, which may eventually entail repainting. A vehicle with its original paint has a higher re-sale value than a repaint. Due to the above; something else to consider is a ‘do nothing’ option and learn to live with it
Reduction - the way light is reflected from a paint surface affects the vehicles appearance after it is detailed. Reflection of light is either Specular (mirror-like) or Diffused (retaining the energy, but losing the image) depending on the nature of the surface. It is also possible for reflection to occur from the surface of transparent media, such as water or glass.
A paint surface that has `orange peel` diffuses the light reflection; a sealant or coating will highlight the orange peel effect as they reflect Specular light (mirror-like) meaning a reflection of the exact image, whereas organic wax reflects a Diffuse light, which is a ‘fractured’ image, an organic wax also shares this reflection trait in the so-called `wet-look` (jetting) So by applying a Carnauba wax to a surface that has `orange peel` you are not masking the effect, but disguising it by making the rest of the paint diffuse light reflection in a similar way.
Authors Profile
.